Striped bass

W44_Morone_saxatilis_ver2

Striped bass 2

 

W44_Morone_saxatilis_vers1

Striped bass 1

Striped bass | Morone saxatilis

Striped bass info via Wikipedia:

Striped bass
Morone saxatilis SI2.jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Moronidae
Genus: Morone
Species: M. saxatilis
Binomial name
Morone saxatilis
(Walbaum, 1792)
Morone saxatilis range.png
Synonyms
  • Perca saxatilis Walbaum, 1792
  • Roccus saxatilis (Walbaum, 1792)
  • Sciaena lineata Bloch, 1792
  • Morone lineatus (Bloch, 1792)
  • Roccus lineatus (Bloch, 1792)
  • Perca mitchilli alternata Mitchill, 1815

The striped bass (Morone saxatilis), also called Atlantic striped bass, striper, linesider, rock, or rockfish, is an anadromous Perciforme fish of the family Moronidae found primarily along the Atlantic coast of North America. It has also been widely introduced into inland recreational fisheries across the United States. Striped bass found in the Gulf of Mexico are a separate strain referred to as Gulf Coast striped bass.[2]

The striped bass is the state fish of Maryland, Rhode Island, and South Carolina, and the state saltwater (marine) fish of New York, New Jersey, Virginia, and New Hampshire.

The history of the striped bass fishery in North America dates back to the Colonial period. Many written accounts by some of the first European settlers describe the immense abundance of striped bass, along with alewives, traveling and spawning up most rivers in the coastal Northeast.[3]

Morphology and lifespan

The striped bass is a typical member of the Moronidae family in shape, having a streamlined, silvery body marked with longitudinal dark stripes running from behind the gills to the base of the tail. Common mature size is 8 to 40 pounds. The largest specimen recorded was 124 pounds, netted in 1896. Striped bass are believed to live for up to 30 years.[4] The maximum length is 1.8 m (5.9 ft).[5] The average size is about 67–100 cm (2.20–3.28 ft).

Distribution

A researcher holding up a large striped bass

Natural distribution

Striped bass are native to the Atlantic coastline of North America from the St. Lawrence River into the Gulf of Mexico to approximately Louisiana. They are anadromous fish that migrate between fresh and salt water. Spawning takes place in fresh water.

Introductions outside their natural range

Striped bass have been introduced to the Pacific Coast of North America and into many of the large reservoir impoundments across the United States by state game and fish commissions for the purposes of recreational fishing and as a predator to control populations of gizzard shad.[6][7][8] These include: Elephant Butte Lake in New Mexico; Lake Ouachita, Lake Norman in North Carolina; Lake Norfork, Beaver Lake and Lake Hamilton in Arkansas; Lake Thunderbird in Illinois; Lake Pleasant, and Lake Havasu in Arizona; Lake Powell along the Arizona/Utah border; Castaic Lake, Pyramid Lake, Silverwood Lake, Diamond Valley Lake, and San Francisco Bay-Delta in California; Lewis Smith Lake in Alabama;[9]Lake Cumberland in Kentucky; Lake George in Florida; Lake Murray in South Carolina; Lake Lanier in Georgia; Watts Bar Lake, in Tennessee; Lake Mead, Nevada; Lake Texoma, Lake Tawakoni, Lake Whitney, Possum Kingdom Lake, and Lake Buchanan in Texas; Raystown Lake in Pennsylvania; Umpqua River in Oregon and in Virginia's Smith Mountain Lake[10] and Leesville Lake.[11]

Striped bass have also been introduced into waters in Ecuador, Iran, Latvia, Mexico, Russia, South Africa, and Turkey, primarily for sport fishing and aquaculture.[4]

Environmental factors

The spawning success of striped bass has been studied in the San Francisco Bay-Delta water system, with a finding that high total dissolved solids (TDS) reduce spawning. At levels as low as 200 mg/l TDS, an observable diminution of spawning productivity occurs.[12] They can be found in lakes, ponds, streams, and wetlands.

Though the population of striped bass was growing and repopulating in the late 1980s and throughout the 1990s, a study executed by the Wildlife and Fisheries Program at West Virginia University found that the rapid growth of the striped bass population was exerting a tremendous pressure on its prey (river herring, shad, and blueback herring). This pressure on their food source was putting their own population at risk due to the population of prey naturally not coming back to the same spawning areas.[13]

In the United States, the striped bass was designated as a protected game fish in 2007, and executive agencies were directed to use existing legal authorities to prohibit the sale of striped bass caught in federal waters in the Atlantic Ocean and Gulf of Mexico.[14]

In Canada, the province of Quebec designated the striped bass population of the Saint Lawrence as extirpated in 1996. Analysis of available data implicated overfishing and dredging in the disappearance. In 2002, a reintroduction program was successful.[15][16]

Lifecycle

A striped bass caught off the New Jersey coast
Preserved specimen
X-ray image

Striped bass spawn in fresh water, and although they have been successfully adapted to freshwater habitat, they naturally spend their adult lives in saltwater (i.e., they are anadromous). Four important bodies of water with breeding stocks of striped bass are: Chesapeake Bay, Massachusetts Bay/Cape Cod, Hudson River, and Delaware River. Many of the rivers and tributaries that emptied into the Atlantic, had at one time, bred stock of striped bass. This occurred until the 1860s.[3] One of the largest breeding areas is the Chesapeake Bay, where populations from Chesapeake and Delaware bays have intermingled.[17] The very few successful spawning populations of freshwater striped bass include Lake Texoma, Lake Weiss (Coosa River), the Colorado River and its reservoirs downstream from and including Lake Powell, and the Arkansas River, as well as Lake Marion (South Carolina) that retained a landlocked breeding population when the dam was built; other freshwater fisheries must be restocked with hatchery-produced fish annually. Stocking of striped bass was discontinued at Lake Mead in 1973 once natural reproduction was verified.[18]

Hybrids with other bass

Striped bass have also been hybridized with white bass to produce hybrid striped bass also known as wiper, whiterock bass, sunshine bass, palmetto bass, and Cherokee bass. These hybrids have been stocked in many freshwater areas across the US.[19][20]

Fishing for striped bass

Striped bass are of significant value for sport fishing, and have been introduced to many waterways outside their natural range. A variety of angling methods are used, including trolling and surf casting with topwater lures a good pick for surf casting, as well as bait casting with live and dead bait. Striped bass will take a number of live and fresh baits, including bunker, clams, eels, sandworms, herring, bloodworms, mackerel, and shad, bluegills, worms, crayfish, bucktails jigs, silver spoons, and sassy shad baits with the last being an excellent bait for freshwater fishing.

The largest striped bass ever taken by angling was an 81.88-lb (37.14-kg) specimen taken from a boat in Long Island Sound, near the Outer Southwest Reef, off the coast of Westbrook, Connecticut. The all-tackle world record fish was taken by Gregory Myerson[21] on the night of August 4, 2011. The fish took a drifted live eel bait, and fought for 20 minutes before being boated by Myerson. A second hook and leader was discovered in the fish's mouth when it was boated, indicating it had been previously hooked by another angler. The fish measured 54 in length and had a girth of 36 in. The International Game Fish Association declared Myerson's catch the new all-tackle world record striped bass on October 19, 2011.[22] In addition to now holding the All-Tackle record, Meyerson's catch also landed him the new IGFA men’s 37-kg (80-lb) line class record for striped bass, which previously stood at 70 lb. The previous all-tackle world record fish was a 78.5-lb (35.6-kg) specimen taken in Atlantic City, New Jersey on September 21, 1982 by Albert McReynolds, who fought the fish from the beach for 1:20 after it took his Rebel artificial lure.[23] Recreational bag limits vary by state and province.

Landlocked striped bass

Striped bass are an anadromous fish, so their upriver spawning migrations led some individuals to become "landlocked" during lake dam constructions. The first area where this was documented was at the Santee-Cooper River during the construction of the two dams that impounded Lakes Moultrie and Marion, and because of this, the state game fish of South Carolina is the striped bass.[24]

Recently, biologists came to believe that striped bass stayed in rivers for long periods of time, with some not returning to sea unless temperature changes forced migration. Once fishermen and biologists caught on to rising striped bass populations, many state natural resources departments started stocking striped bass in local lakes. Striped bass still continue to exhibit upstream migrations from freshwater lakes during the spawning period. Landlocked stripers have a hard time reproducing naturally, and one of the few and most successful rivers they have been documented reproducing successfully is the Coosa River in Alabama and Georgia.[25]

A 70.6-lb (32.0-kg) landlocked bass was caught in February 2013 by James Bramlett on the Warrior River in Alabama, a current world record.[26] This fish had a length of 44 inches (110 cm) and a girth of 37.75 inches (95.9 cm).

One of the only landlocked striped bass populations in Canada is located in the Grand Lake, Nova Scotia. They migrate out in early April into the Shubenacadie River to spawn. These bass also spawn in the Stewiacke River (a tributary of the Shubenacadie). The Shubenacadie River system is one of five known spawning areas in Canada for striped bass, with the others being the St. Lawerence River, Miramichi River, Saint John River, Annapolis River and Shubenacadie/Stewiacke Rivers.[27]

Management

The striped bass population declined to less than 5 million by 1982, but efforts by fishermen and management programs to rebuild the stock proved successful, and in 2007, there were nearly 56 million fish, including all ages. Recreational anglers and commercial fisherman caught an unprecedented 3.8 million fish in 2006. The management of the species includes size limits, commercial quotas, and biological reference points for the health of the species. The Atlantic States Marine Fisheries Commission states that striped bass are "not overfished and overfishing is not occurring."[28] Another way to replenish and help repopulate the striped bass population is to reintroduce the species back to original spawning grounds in coastal rivers and estuaries in the Northeast.[3]

As food

Striped bass (3 oz, baked)
Nutritional value per 100 g (3.5 oz)
Energy 461 kJ (110 kcal)
0 g
3 g
Saturated 1 g
Polyunsaturated
0.8 g
19 g
Minerals
Sodium
(5%)
75 mg

Source: Seafood Nutrition Chart, New York Sea Grant and the New York Seafood Council, 1996.[29]
Percentages are roughly approximated using US recommendations for adults.
Striped bass brisket with a lima-fava bean puree

Striped bass has white meat with a mild flavor and a medium texture. It is extremely versatile in that it can be pan-seared, grilled, steamed, poached, roasted, broiled, sautéed, and deep fried (including batter-frying).[30] The flesh can also be eaten raw or pickled.[31][32]

The primary market forms for fresh bass include headed and gutted (with the head and organs removed) and filets; the primary market forms for frozen bass include headed and gutted and loins. It can also be found in steaks, chunks, or whole.[29] Fresh striped bass is available year-round,[30] and is typically sold in sizes from two to fifteen pounds, and can be sold up to fifty pounds.[32]

Striped bass has firm and flavorful flesh with a large flake.[32] The hybrid striped bass yields more meat, has a more fragile texture, and a blander flavor than wild striped bass.[33] The fish has a mild and distinctive flavor. In recipes, it can be substituted for milder fish like cod, as well as for stronger fish like bluefish. Other fish can substitute it, including weakfish, tilefish, blackfish, small bluefish, catfish, salmon, swordfish, and shark. Striped bass is easily grilled in fillets, and is therefore popular in beach communities.[29]

References

  1. ^ NatureServe (2015). "Morone saxatilis". IUCN Red List of Threatened Species. Version 4.1 (4.1). International Union for Conservation of Nature. 
  2. ^ Gulf Coast Striped Bass. Welaka National Fish Hatchery. Fws.gov (September 16, 2009). Retrieved on 2016-11-15.
  3. ^ a b c Little, Michael J. (1995). "A Report on the Historic Spawning Grounds of the Striped Bass, "Morone Saxatilis"". Maine Naturalist. 3 (2): 107–113. JSTOR 3858211. 
  4. ^ a b Froese, Rainer and Pauly, Daniel, eds. (2007). "Morone saxatilis" in FishBase. March 2007 version.
  5. ^ National Audubon Society (May 2001). National Audubon Society Field Guide to North American Fishes. Knopf, Rev Sub edition (May 21, 2002). ISBN 0375412247. 
  6. ^ Striped Bass Management Plan retrieved on June 10, 2007.
  7. ^ Pennsylvania State Fish & Boat Commission, Gallery of Pennsylvania Fishes, Chapter 21. Retrieved June 10, 2007.
  8. ^ Indiana Fish and Wildlife, Evaluation of Striped Bass Stockings at Harden Reservoir. Retrieved June 10, 2007.
  9. ^ East Fork Lake Fishing Map. ODNR Division of Wildlife. state.oh.us
  10. ^ Lakes | VDGIF. Dgif.virginia.gov. Retrieved on November 15, 2016.
  11. ^ Lakes | VDGIF. Dgif.virginia.gov. Retrieved on November 15, 2016.
  12. ^ Kaiser Engineers, California (1969). Final Report to the State of California, San Francisco Bay-Delta Water Quality Control Program, State of California, Sacramento, CA
  13. ^ Hartman, K. J. (2003). "Population-level consumption by Atlantic coastal striped bass and the influence of population recovery upon prey communities". Fisheries Management and Ecology. 10 (5): 281. doi:10.1046/j.1365-2400.2003.00365.x. 
  14. ^ "Executive Order 13449: Protection of Striped Bass and Red Drum Fish Populations". Office of the Federal Register. October 20, 2007. Retrieved October 24, 2007. 
  15. ^ "Reintroduction of the striped bass into the St. Lawrence" (PDF) (2nd ed.). Minister of the Environment. 2008. Retrieved May 12, 2014. 
  16. ^ "Reproduction of striped bass - A historical first: spawning ground identified in Montmagny". Gouvernement du Québec, 2003-2012. September 1, 2011. Retrieved May 12, 2014. 
  17. ^ Striped Bass Morone saxatilis. Chesapeake Bay Program
  18. ^ Wilde, G. R. and L.J. Paulson (1989). "Food habits of subadult striped bass in Lake Mead Arizona-Nevada". The Southwestern Naturalist. 34 (1): 118–123. JSTOR 3671816. 
  19. ^ Illinois Department of Natural Resources, Status of the Striped Bass/Hybrid Bass Bass Fishery March 2006 retrieved June 10, 2007.
  20. ^ Pennsylvania State Fish & Boat Commission, Gallery of Pennsylvania Fishes, Chapter 21. Retrieved June 10, 2007.
  21. ^ Greg Myerson's World Record Striper Official Website. Worldrecordstriper.com. Retrieved on November 15, 2016.
  22. ^ IGFA all-tackle world record striped bass. Igfa.org. Retrieved on November 15, 2016.
  23. ^ DiBenedetto, David (October 13, 2009). On the Run: An Angler's Journey Down the Striper Coast. HarperCollins. p. 195. ISBN 978-0-06-187735-3. 
  24. ^ "History of Freshwater Striped Bass". Retrieved March 1, 2010. 
  25. ^ "Striped Bass in River Systems". Retrieved March 1, 2010. 
  26. ^ "Word Record Landlocked Bass". May 2013. 
  27. ^ Aquatic Species at Risk - Striped Bass (Bay of Fundy Population). Fisheries and Oceans Canada
  28. ^ "Atlantic States Marine Fisheries Commission: Striped Bass" (PDF). Retrieved July 2, 2009. 
  29. ^ a b c "Striped Bass". New York Seafood Council. Retrieved February 5, 2015. 
  30. ^ a b "East Coast Striped Bass: Prep & Nutrition". Seattle Fish Company. Retrieved February 5, 2015. 
  31. ^ Ainsworth, Mark (2009). Fish and Seafood: Identification, Fabrication, Utilization. Clifton Park, New York: Delmar, Cengage Learning. p. 44. ISBN 978-1-4354-0036-8. 
  32. ^ a b c The Culinary Institute of America (2011). The Professional Chef (9th ed.). Hoboken, New Jersey: John Wiley & Sons. p. 108. ISBN 978-0-470-42135-2. OCLC 707248142. 
  33. ^ McGee, Harold (2004). On Food and Cooking: the Science and Lore of he Kitchen. New York, New York: Scribner. p. 200. ISBN 978-0-684-80001-1. LCCN 2004058999. 

External links

source: http://en.wikipedia.org/wiki/Striped_bass

 

Florida pompano

91W_Trachinotus_carolinus_vers1_80x24

Florida pompano | Trachinotus carolinus

Florida pompano info via Wikipedia:

Florida pompano
Pompano common.jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Carangidae
Genus: Trachinotus
Species: T. carolinus
Binomial name
Trachinotus carolinus
(Linnaeus, 1766)

The Florida pompano (Trachinotus carolinus[2]) is a species of marine fish in the Trachinotus (pompano) genus of the family Carangidae. It has a compressed body and short snout; coloration varies from blue-greenish silver on the dorsal areas and silver to yellow on the body and fins. It can be found along the western coast of the Atlantic Ocean, depending on the season, and is popular for both sport and commercial fishing. Most Florida pompano caught weigh less than 3 lb (1.4 kg) and are less than 17 in (43 cm) long, though the largest individuals weigh 8–9 lb (3.6–4.1 kg) and reach lengths up to 26 in (66 cm).

Because it is fast-growing and desirable for food, the pompano is one of the many fish that is currently being farmed through aquaculture.

The Florida city of Pompano Beach is named after the Florida pompano.

Description

The different kinds of pompano include African, Cayenne, Florida and Irish. The Florida pompano (T. carolinus) is part of the jack family. It is very similar to the permit (Trachinotus falcatus). It has a deeply forked tail and is blue-greenish silver with yellow on the throat, belly, and pelvic and anal fins. The first dorsal fins are low, with about six separate spines. The first spine may be reabsorbed in a larger fish. The second lobes on the dorsal and anal fins have a lower anterior.[3] There are 20-24 anal fin rays. It is a compressed fish with a deep body and a blunt snout.

Trachinotus carolinus, Rio Grande do Sul, Brazil

Size

Pompano WL.png

Juvenile pompano grow between 0.8 and 1.9 in (20 and 48 mm) per month, depending on the population. Pompano grow quickly and attain a length of about 12 in (30 cm) and a weight of about 1 lb (0.45 kg) after the first year. The relationship between total length (L, in inches) and total weight (W, in pounds) for nearly all fish can be expressed by an equation of the form: W = c L b {\displaystyle W=cL^{b}\!\,} W=cL^{b}\!\,

Invariably, b is close to 3.0 for all species, and c is a constant that varies among species.[4] A weight-length relationship was determined for a sample of 1,984 Florida pompano collected along the Gulf Coast of Florida between 2000 and 2002.[5] The fish sampled ranged in length from 79–481 mm (3.16-19.24 in). For this sample of Florida pompano, b = 2.9342 and c = 0.00076.

This relationship predicts that a 12-inch (300 mm) pompano will weigh about a pound. Most are less than three pounds when caught, though the largest pompano recorded have weighed 8-9 lb and were 23-25 in long.

Lifespan

The Florida pompano usually survives for only about three to four years,[6] although individuals as old as 6-7 yr have been caught.[5]

Range and habitat

The adult Florida pompano is typically found in more saline areas and relatively warm waters (70-89 °F), so it migrates northward in the summer, and toward the south in the fall.[6] Despite its name, the range of the Florida pompano extends from Massachusetts to Brazil, but it is more common in areas near Florida. During the summer, it can be found near Sebastian, Cape Hatteras, and the Gulf of Mexico. It is more common near oil rigs, Palm Beach, and Hobe Sound during the winter. It can also be found near the Virgin Islands year round.

Its habitat is surf flats, and it tends to stay away from clear water regions, such as the Bahamas.[7] Pompanos are very fast swimmers and live in schools. They are bottom feeders. They have very short teeth and feed on zoobenthos and small clams.

Ecology

Food

The pompano is a popular food fish. Chefs like it because the fillets are of even thickness, which aids in cooking. A popular dish created in New Orleans, called “pompano en papillote,” is wrapped in parchment paper with a white sauce of wine, shrimp, and crabmeat, and then steamed.[8]

The pompano’s flesh is oily and looks white and opaque. Its diet yields a rich but mild flavor. Fresh fillets can cost $17 or more.[9] Demand has encouraged the use of aquaculture to increase supply.

Aquaculture

The Florida pompano is a popular choice for aquaculture because it is such a popular food and sport fish and is in high demand, and at the same time it has a fast growth rate, high dockside prices,[10] and a tolerance for low-salinity waters.[10] The typical market size of farm-raised pompano is 1 to 1.5 lb (0.45 to 0.68 kg).[11]


Fishing

The pompano supports an important commercial and recreational fishery. Florida pompano are commercially fished in all states on the East Coast from Virginia to Texas, with Florida producing over 90% of the annual harvest. Harvesting occurs mostly along Florida's western coast, with some harvesting on the eastern coast and in the Banana and Indian Rivers. Between 1994 and 2006, it commanded dockside prices of more than $3 per pound of whole fish weight.[11]

Individually, Florida pompano are caught on light jigs and popping corks. They are very active on the line, testing light tackle beyond what their weight would suggest.[8] They bite near oil rigs in the winter.

From 1997-2000, the fishing mortality rates increased sharply. However, an extensive study by the Florida Fish and Wildlife Conservation Commission concluded, as of 2005, the population of Florida pompano was healthy and the fishery was sustainable with current practices.[5][8]

References

  1. ^ Smith-Vaniz, W.F.; Williams, J.T.; Pina Amargos, F.; Curtis, M.; Brown, J. (2015). "Trachinotus carolinus". The IUCN Red List of Threatened Species. IUCN. 2015: e.T16507646A16510412. doi:10.2305/IUCN.UK.2015-4.RLTS.T16507646A16510412.en. Retrieved 10 August 2017. 
  2. ^ Froese, Rainer and Pauly, Daniel, eds. (2006). "Trachinotus carolinus" in FishBase. April 2006 version.
  3. ^ Smith, C. Lavett, National Audubon Society Field Guide to Tropical Marine Fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda. Chanticleer Press, 1997, ISBN 0-679-44601-X, color plate 268, p. 490
  4. ^ R. O. Anderson and R. M. Neumann, Length, Weight, and Associated Structural Indices, in Fisheries Techniques, second edition, B.E. Murphy and D.W. Willis, eds., American Fisheries Society, 1996.
  5. ^ a b c Murphy, M.D., Muller, R.G., Guindon, K. A stock assessment for pompano, Trachinotus carolinus, in Florida waters through 2005. Report to the Florida Fish and Wildlife Conservation Commission, Division of Marine Fisheries Management. In-house report 2008-004, 2008.
  6. ^ a b ESPN page on Florida pompano Archived 2006-05-27 at the Wayback Machine.
  7. ^ Smithsonian Marine Station page on Florida pompano
  8. ^ a b c Ristori, Al. The Saltwater Fish Identifier. New York: Mallard Press, 1992, ISBN 0-7924-5575-4, pp. 44
  9. ^ "Archived copy". Archived from the original on 2010-04-13. Retrieved 2010-06-12. 
  10. ^ a b rch%20and%20Development MOTE Marine Laboratory aquaculture of Florida pompano
  11. ^ a b Southern Regional Aquacultural Center (Texas A&M) Species Profile on Florida pompano 2007[permanent dead link]
source: http://en.wikipedia.org/wiki/Florida_pompano

Longnose Gar

75W_Lepisos_osseus_60x20

Longnose Gar | Lepisosteus osseus

Longnose Gar info on Wikipedia:

Longnose gar
Longnose gar, Boston Aquarium.JPG
At the New England Aquarium
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Lepisosteiformes
Family: Lepisosteidae
Genus: Lepisosteus
Species: L. osseus
Binomial name
Lepisosteus osseus
(Linnaeus, 1758)
Synonyms[2][3]

The longnose gar (Lepisosteus osseus) is a primitive ray-finned fish of the gar family. It is also known as the needlenose gar. L. osseus is found along the east coast of North and Central America in freshwater lakes and as far west as Kansas and Texas and southern New Mexico. The gar have been present in North America for about 100 million years.[4]

Distribution

Fossils have been found in Africa, Asia, Europe, North America, and South America dating back 100 million years. Currently, longnose gar are found in Central America, Cuba, North America, and the Isles of Pines.[5] Longnose gar are frequently found in fresh water in the eastern half of the United States, but some gar were found in salinities up to 31 ppt.[6] Their microhabitats consist of areas near downed trees, stone outcrops, and vegetation.[7] The decline of their population is mainly due to human manipulation of aquatic systems.

Ecology

The most common prey of the longnose gar is small fish and occasionally insects and small crustaceans, and mostly feed at night.[8] Their main competitors are other gar of their own species, as well as other types of gar. Larger gar have been known to feed on smaller gar, as well.[9] Longnose gar were a main source of food for Native Americans and early colonists. The first settlers at Jamestown, Virginia, dined on this fish through their harsh early years.[10] Today, gar is more of sport fish, but their meat is surprisingly tasty. Predation is not a problem on adult longnose gar, but they are vulnerable to other gar predation when they are young, including adult longnose gar. L. osseus is carnivorous; for example, their diet consists of sunfish, catfish, and crayfish in their Texas range.[9] Sexual maturity for males is reached between three and four years of age, and females at six years of age. Sex ratios are in favor of the males in the early life stages until about 10 years, then switches in favor of females. Females hold an average clutch size of about 27,000 eggs. Their eggs are very toxic to terrestrial vertebrates, but other piscivorous fish could tolerate the toxins.[11]

Life history

Longnose gar have an average lifespan of 15–20 years with a maximum reported age of 39. This long lifespan allows the female to sexually mature around six years old. Males mature sexually as soon as two years of age. Longnose gars are sexually dimorphic; the females are larger than the males in body length, weight, and fin length. They generally have a clutch size close to 30,000, depending on the weight to length ratio of the females; larger females bear larger clutch sizes. They spawn in temperatures close to 20 °C in late April and early July.[11] Eggs have a toxic, adhesive coating to help them stick to substrates, and they are deposited onto stones in shallow water, rocky shelves, vegetation, or smallmouth bass nests.[12] Their hatch time is seven to 9 days; young gar stay in vegetation during the first summer of life.[8] Longnose gar reach an average length of 28-48 in (0.71-1.2 m) with a maximum length of about 6 ft (1.8 m) and 55 lb (25 kg) in weight.

Management

Currently, no management of this species is being conducted, nor is it federally listed as endangered, although some states have reported it as threatened (South Dakota, Delaware, and Pennsylvania).[13] In the early 1900s, longnose gar were considered as destructive and worthless predators. Many people feared them based on their spooky appearance of a long mouth filled with teeth and armor-like scales, as well as their diet of anything that would fit in their mouths. Soon after this characterization, gar population reduction methods were established. Their declining populations are due to overfishing, habitat loss, dams, road construction, pollution, and other human-caused destruction of the aquatic systems. Overfishing is more of a trophy fish than for food; people find their meat to have a mild but tasty flavor. Because of their long lifespans and older sexual maturity age, factors affecting their reproduction is an issue in preserving them.[14] Overfishing is a large issue for this fish, especially when the fish have not reached sexual maturity due to the female not peaking sexual maturity until about six years of age.[14][15]

References

  1. ^ NatureServe (2015). "Lepisosteus osseus". IUCN Red List of Threatened Species. Version 4.1 (4.1). International Union for Conservation of Nature. Retrieved April 7, 2016. 
  2. ^ Froese, R.; Pauly, D. (2017). "Lepisosteidae". FishBase version (02/2017). Retrieved 18 May 2017. 
  3. ^ "Lepisosteidae" (PDF). Deeplyfish- fishes of the world. Retrieved 18 May 2017. 
  4. ^ McGrath, P.E., E.J. Hilton (2011). Sexual dimorphism in longnose gar Lepisosteus osseus. Journal of Fish Biology 80(2)335-345.
  5. ^ Wiley, E.O. (1976). The phylogeny and biogeography of fossil and recent gars (Actinopterygii: Lepisosteidae). Miscellaneous Publication, University of Kansas, Museum of Natural History 64.
  6. ^ Uhler, P.R. & O. Lugger. (1876). List of fishes of Maryland. Report of the Commissioners of Fisheries of Maryland, to the General Assembly
  7. ^ Suttkus, R.D. (1963). Order Lepisostei. In: Fishes of the Western North Atlantic, Memoir 1, Part Three, of the Sears Foundation for Marine Research (H. B. Bigelow, C. M. Cohen, G. W. Mead, D. Merriman, Y. H. Olsen, W. C. Schroeder, L. P. Schultz, and J. Tee-Van, eds.), pp. 61-88. New Haven, CT: Yale University.
  8. ^ a b Haase, B.L. (1969). An ecological life history of the longnose gar, Lepisosteus osseus (Linnaeus), in Lake Mendota and in several other lakes of southern Wisconsin. Dissertation, The University of Wisconsin - Madison, Madison, Wisconsin.
  9. ^ a b Bonham, Kelshaw. (1941). Food of gars in Texas. Transactions of the American Fisheries Society 70(1):356-362.
  10. ^ Straube, B. and N. Luccketti. (1996). Jamestown rediscovery 1995 interim report. November 2006. The Association for the Preservation of Virginia Antiquities, 55 p.
  11. ^ a b Netsh, Norval F., Arthur Witt Jr. (1962). Contributions to the Life History of the Longnose Gar (Lepisosteus osseus) in Missouri. Transactions of the American Fisheries Society 91(3):251-262.
  12. ^ Beard, J. (1889). On the early development of Lepidosteus osseus. Proceedings of the Royal Society of London 46:108-118.
  13. ^ Johnson, Brian L., Douglas B. Noltie. (1997). Demography, Growth, and Reproductive Allocation in Stream-Spawning Longnose Gar. Transactions of the American Fisheries Society 126:438-466.
  14. ^ a b Alfaro, Roberto Mendoza, et al. (2008). Gar biology and culture: status and prospects. Aquaculture Research 39:748-763
  15. ^ Spitzer, Mark (2010). Season of the Gar: Adventures in Pursuit of America's Most Misunderstood Fish. U. of Arkansas Press.
source: http://en.wikipedia.org/wiki/Longnose_gar

Smallmouth Buffalo

Smallmouth Buffalo

Smallmouth Buffalo| Ictiobus bubalus

Smallmouth Buffalo info on Wikipedia:

Smallmouth buffalo
Smallmouth buffalo.JPG
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Catostomidae
Genus: Ictiobus
Species: I. bubalus
Binomial name
Ictiobus bubalus
(Rafinesque, 1818)
Smallmouth Buffalo Distribution.png
The distribution of I. bubalus in the United States
Synonyms
  • Catostomus bubalus Rafinesque, 1818

The smallmouth buffalo (Ictiobus bubalus, from the Greek for "bull-fish" and "buffalo") is a Cypriniformes fish species found in the major tributaries and surrounding waters of the Mississippi River in the United States as well as some other water systems where it has been introduced. It is a stocky fish like its relatives the bigmouth buffalo (Ictiobus cyprinellus) and the black buffalo (Ictiobus niger), although the smallmouth buffalo's mouth is located ventrally like other Catostomidae species while the bigmouth buffalo's mouth is terminal and opens forward, and the smallmouth buffalo's eyes are significantly larger than those of the black buffalo. These three species are superficially similar to the common carp (Cyprinus carpio), but all lack the characteristic barbels.

Physical characteristics

The coloration of smallmouth buffalo ranges from shades of gray to brown and coppery green dorsally and pale yellow to white ventrally. Fin colors match the portion of the body they attach to and are generally darker towards the tips. They are characteristically stocky, having a hump that rises up from where the operculum sits. Pectoral fins protrude ventrally like the anal fins, the caudal fin has even lobes, and the dorsal fin protrudes from the top of the hump to a blunt point then shortens and runs the remaining length of the body to the base of the tail. Average adults reach a length of around 40–60 cm (16–24 in) with some specimens reaching as much as 90 cm (35 in).

Habitat

The smallmouth buffalo is a hardy fish that frequents clear, moderate to fast-moving streams but has been occasionally known in some lakes and ponds. If prefers waters with dense aquatic vegetation and a silty bottom. It has a high tolerance for hard water and can survive in waters with pH ranges of 6.5–8.5.

Diet

The smallmouth buffalo's diet is primarily that of a detritivore, using its ventral sucker mouth to pick up vegetation and other organic matter from the bottom of its habitat, often scraping algae off of rocks. It is also quite the invertivore, consuming zooplankton, insect larvae, mollusk larvae and small crustaceans.

Reproduction

Spawning usually takes place in spring and summer with more specific timeframes depending on the location of the population. Migration is negligible. Spawning often occurs in shallower sections of streams where the egg can adhere to vegetation and gravel to keep from flowing away. Each female can lay tens of thousands to hundreds of thousands of eggs at a time depending on her size, so no parental care is applied and the eggs hatch in one or two weeks. The young hide in aquatic vegetation to avoid predators. The average lifespan of a smallmouth buffalo is nine to eighteen years with males reaching sexual maturity in four to five years and females at around six years.

Commercial uses

Although considered by many to be a rough fish, smallmouth buffalo is the most common commercially sold freshwater fish in the United States. The species is highly valued by some as a human food source and the fish meal is common in animal feed. They are relatively quick and easy to raise in commercial farm ponds. Anglers seeking to hook a smallmouth buffalo have found success with doughballs and corn on hooks.[citation needed]

References

[2][3][4]

  1. ^ NatureServe (2013). "Ictiobus bubalus". IUCN Red List of Threatened Species. Version 2014.1. International Union for Conservation of Nature. Retrieved 22 August 2017. CS1 maint: Uses authors parameter (link)
  2. ^ "Ohio Boating Accident Data Archive". Dnr.state.oh.us. Retrieved 2017-02-26. 
  3. ^ "Smallmouth Buffalo (Ictiobus bubalus)". Tpwd.state.tx.us. Retrieved 2017-02-26. 
  4. ^ "Smallmouth Buffalo (Ictiobus bubalus) - FactSheet". Nas.er.usgs.gov. Retrieved 2017-02-26. 

External links

source: http://en.wikipedia.org/wiki/Smallmouth_buffalo


Guadalupe Bass (Williamson County, TX)

Micropterus treculii, Guadalupe Bass

Guadalupe Bass | Micropterus treculii

collected March 2012, Brushy Creek, Williamson County, Texas, USA
printed March 2012
India ink on paper

 

We’ve printed this species  before – see our previous versions with a different specimen. We figured we’d try it again after running across this beautiful specimen in Brushy Creek just north of Austin.  See the photo below. It’s colors and patterns have changed a bit since we collected it. At that time it had some of the vertical barring typical of Guadalupe bass.

I really like the look of specimens with ink on them. All color is hidden and you start to notice things you wouldn’t otherwise. In this case the ink and the angle of the reflecting light allows you to see the individual scales in great detail. Notice how small the cheek scales are compared to the body scales. I recently learned that this is a good character for distinguishing Guadalupe bass and spotted bass from the largemouth bass which has cheek scales similar in size to the body scales.

Guadalupe Bass

Guadalupe Bass Gyotaku by Inked Animal

Guadalupe Bass | Micropterus treculii

The state fish of Texas!  Since 1989. This baby is one of around 10(?) bass in America, and is only found in central Texas.  Adam and I have collected fish together all over the state, and at least for me, this fish is one of those that when you catch it, you appreciate it. Especially a decent size one like this specimen.  This fish is special for many reasons, among them is that its only found in Texas, and its in danger of being bred out by the native spotted (Micropterus punctulatus) and large mouth (Micropterus salmoides) basses as well as the invasive small mouth bass (Micropterus dolomieu). Texas Parks and Wildlife department list it as a State Threatened fish.

I think the Guadalupe Bass should be the grand prize of any freshwater fisherman in Texas.  I’ve got a good friend with a fly fishing blog specializing in central Texas fishing, he has many maps and posts about catching this special fish.  Check him out at diefische.

We hope you like our Gyotaku of the Guadalupe Bass. Notice the detail of the scales behind the eye, good stuff.  This is our only one for the G.bass so far, and we’re determined to do some more with other specimens once they’re caught.  We still need to get an open mouth bass print! But that will probably be reserved for the large mouth….which is also still to come.


 

Guadalupa Bass info via Wikipedia:

Guadalupe Bass
File:Guadalupe Bass - Micropterus treculii.jpg
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Centrarchidae
Genus: Micropterus
Species: M. treculii
Binomial name
Micropterus treculii
(Vaillant & Bocourt, 1883)

The Guadalupe Bass (Micropterus treculii) is a rare species of fish endemic to the U.S. state of Texas, where it also is the official state fish. It is restricted to creeks and rivers (including the Guadalupe River, hence the name Guadalupe Bass), and is listed as Near Threatened.[2] Today, most fly fishermen and anglers practice catch-and-release techniques to improve fish populations. The Guadalupe Bass is often difficult to distinguish from the smallmouth bass or spotted bass, and the fish is known to hybridize.

Description and range

Guadalupe Bass, like most black bass, are lime to olive green in color, this particular species being lighter in shade usually in river specimens. They have a lateral line covered in mostly separate diamond shaped or circular spots, which with age fades from black to olive. There are also many smaller diamond marks scattered on the back which are less distinguished than the ones on the lateral line. Its physical traits are very similar to the spotted bass (i.e. small mouth that doesn't extend past the eye, sleek figure, etc.) with one exception: the green coloring tends to extend lower on the body past the lateral line than their cousins. So far the record is 3.71 lbs (3 lbs 11.360 oz.), caught by Dr. Bryan Townsend of Austin in 2014. The fish is only found in Edward's Plateau in central Texas. Its main habitats are the San Marcos, Colorado, Llano, and Guadalupe rivers. They can also be found in run-off creeks such as Barton Creek, Onion Creek, San Gabriel river, and The Comal river. The species has also been farm raised and stocked in the Llano river.

Threats and predators

The Guadalupe Bass has almost no predators. In fact its main threat is not predation, but hybridization with the introduced smallmouth bass. The two species are very closely related and in some rivers almost half the Guadalupe Bass are hybrids. The Texas Parks and Wildlife Dept. stated it will likely stock many bass in the future to beat out the hybrid population. This will be a pilot for several other areas where rare spotted bass sub-species are having the same problems.

Habitat

Typically, Guadalupe Bass are found in streams and reservoirs; they are absent from extreme headwaters. The Guadalupe Bass prefer flowing waters of streams within native variety, and use covers like large rocks, cypress trees or stumps for refuge.

Diet

The fish (especially juveniles and very old fish), unlike other bass, have an inclination towards insects. Guadalupe Bass at their predatory peak prefer larger bait fish such as shad and small bass or bluegill.

Fishing

While almost unheard of elsewhere, the Guadalupe Bass is very popular among fishermen in central Texas. It is cherished for its long tough fights, in which it manipulates the current and its unusually strong muscles, and beautiful colors which tend to be more natural and bright than those of spotted bass. Its preference for strong current and its large diet of insects earned it the name "Texas Brook Trout" and make it popular for fly fishermen. It fights similarly to both smallmouth bass and Rainbow Trout—making long runs and manipulating current, but also making sharp turns and attempting to entangle the line on structures, and even making large jumps like both species. Altogether, it makes a very satisfying fight, and it can be difficult and extremely fun to land a 2+ lb. fish.

If fishing in a larger river, one will most likely find large fish in deep pools with some current, scavenging off whatever the current brings, and in the shallows, looking for fry, bait fish, frogs, the occasional rodent, and hatching insects if in the right season. Smaller fish are found in fast current behind riffles, eating passing nymphs that were sucked in and small minnows eating the same. Due to their preference for small fish and insects, fly fishermen are at a large advantage.

References

  1. ^ NatureServe (2014). "Micropterus treculii". The IUCN Red List of Threatened Species. IUCN. 2014: e.T13405A19032728. doi:10.2305/IUCN.UK.2014-3.RLTS.T13405A19032728.en. Retrieved 10 November 2017. 
  2. ^ Gimenez Dixon, M. (1996). "Micropterus treculii". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 12 June 2014. 

Sources

source: http://en.wikipedia.org/wiki/Guadalupe_bass

Blacktip Shark 3

 

Blacktip Shark Gyotaku #3 by Inked Animal

Blacktip Shark | Carcharhinus limbatus


Blacktip Shark info via Wikipedia:

Not to be confused with the blacktip reef shark, Carcharhinus melanopterus.
Blacktip shark
Carcharhinus limbatus (2).jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Carcharhinus
Species: C. limbatus
Binomial name
Carcharhinus limbatus
(J. P. Müller & Henle, 1839)
Carcharhinus limbatus distmap.png
Range of the blacktip shark
Synonyms

Carcharias abbreviatus Klunzinger, 1871
Carcharias aethalorus Jordan & Gilbert, 1882
Carcharias ehrenbergi Klunzinger, 1871
Carcharias maculipinna Günther, 1868
Carcharias microps Lowe, 1841
Carcharias muelleri Steindachner, 1867
Carcharias phorcys Jordan & Evermann, 1903
Carcharias pleurotaenia Bleeker, 1852
Carcharhinus natator Meek & Hildebrand, 1923

The blacktip shark (Carcharhinus limbatus) is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of 1.5 m (4.9 ft).

Swift, energetic piscivores, blacktip sharks are known to make spinning leaps out of the water while attacking schools of small fish. Their demeanor has been described as "timid" compared to other large requiem sharks. Both juveniles and adults form groups of varying size. Like other members of its family, the blacktip shark is viviparous; females bear one to 10 pups every other year. Young blacktip sharks spend the first months of their lives in shallow nurseries, and grown females return to the nurseries where they were born to give birth themselves. In the absence of males, females are also capable of asexual reproduction.

Normally wary of humans, blacktip sharks can become aggressive in the presence of food and have been responsible for a number of attacks on people. This species is of importance to both commercial and recreational fisheries across many parts of its range, with its meat, skin, fins, and liver oil used. It has been assessed as Near Threatened by the IUCN, on the basis of its low reproductive rate and high value to fishers.

Taxonomy

The blacktip shark was first described by French zoologist Achille Valenciennes as Carcharias (Prionodon) limbatus in Johannes Müller and Friedrich Henle's 1839 Systematische Beschreibung der Plagiostomen. The type specimens were two individuals caught off Martinique, both of which have since been lost. Later authors moved this species to the genus Carcharhinus.[1][2] The specific epithet limbatus is Latin for "bordered", referring to the black edges of this shark's fins.[3] Other common names used for the blacktip shark include blackfin shark, blacktip whaler, common or small blacktip shark, grey shark, and spotfin ground shark.[4]

Phylogeny and evolution

The closest relatives of the blacktip shark were originally thought to be the graceful shark (C. amblyrhynchoides) and the spinner shark (C. brevipinna), due to similarities in morphology and behavior. However, this interpretation has not been borne out by studies of mitochondrial and ribosomal DNA, which instead suggest affinity with the blacknose shark (C. acronotus). More work is required to fully resolve the relationship between the blacktip shark and other Carcharhinus species.[5]

Analysis of mitochondrial DNA has also revealed two distinct lineages within this species, one occupying the western Atlantic and the other occupying the eastern Atlantic, Indian, and Pacific Oceans. This suggests that Indo-Pacific blacktip sharks are descended from those in the eastern Atlantic, while the western Atlantic sharks became isolated by the widening Atlantic Ocean on one side and the formation of the Isthmus of Panama on the other. Blacktip sharks from these two regions differ in morphology, coloration, and life history characteristics, and the eastern Atlantic lineage may merit species status.[6] Fossil teeth belonging to this species have been found in Early Miocene (23–16 Ma) deposits in Delaware and Florida.[7][8]

Description

The blacktip shark has a robust, streamlined body with a long, pointed snout and relatively small eyes. The five pairs of gill slits are longer than those of similar requiem shark species.[1] The jaws contain 15 tooth rows on either side, with two symphysial teeth (at the jaw midline) in the upper jaw and one symphysial tooth in the lower jaw. The teeth are broad-based with a high, narrow cusp and serrated edges.[2] The first dorsal fin is tall and falcate (sickle-shaped) with a short free rear tip; no ridge runs between the first and second dorsal fins. The large pectoral fins are falcate and pointed.[1]

The coloration is gray to brown above and white below, with a conspicuous white stripe running along the sides. The pectoral fins, second dorsal fin, and the lower lobe of the caudal fin usually have black tips. The pelvic fins and rarely the anal fin may also be black-tipped. The first dorsal fin and the upper lobe of the caudal fin typically have black edges.[1] Some larger individuals have unmarked or nearly unmarked fins.[3] Blacktip sharks can temporarily lose almost all their colors during blooms, or "whitings", of coccolithophores.[9] This species attains a maximum known length of 2.8 m (9.2 ft), though 1.5 m (4.9 ft) is more typical, and a maximum known weight of 123 kg (271 lb).[4]

Distribution and habitat

A blacktip shark swimming in murky water off Oahu, Hawaii

The blacktip shark has a worldwide distribution in tropical and subtropical waters. In the Atlantic, it is found from Massachusetts to Brazil, including the Gulf of Mexico and the Caribbean Sea, and from the Mediterranean Sea, Madeira, and the Canary Islands to the Democratic Republic of the Congo. It occurs all around the periphery of the Indian Ocean, from South Africa and Madagascar to the Arabian Peninsula and the Indian subcontinent, to Southeast Asia. In the western Pacific, it is found from the Ryukyu Islands of Japan[10] to northern Australia, including southern China, the Philippines and Indonesia. In the eastern Pacific, it occurs from Baja California to Peru. It has also been reported at a number of Pacific islands, including New Caledonia, Tahiti, the Marquesas, Hawaii, Revillagigedo, and the Galápagos.[1]

Most blacktip sharks are found in water less than 30 m (98 ft) deep over continental and insular shelves, though they may dive to 64 m (210 ft).[4] Favored habitats are muddy bays, island lagoons, and the drop-offs near coral reefs; they are also tolerant of low salinity and enter estuaries and mangrove swamps. Although an individual may be found some distance offshore, blacktip sharks do not inhabit oceanic waters.[1] Seasonal migration has been documented for the population off the east coast of the United States, moving north to North Carolina in the summer and south to Florida in the winter.[11]

Biology and ecology

The blacktip shark is an extremely fast, energetic predator that is usually found in groups of varying size.[3] Segregation by sex and age does not occur; adult males and nonpregnant females are found apart from pregnant females, and both are separated from juveniles.[1] In Terra Ceia Bay, Florida, a nursery area for this species, juvenile blacktips form aggregations during the day and disperse at night. They aggregate most strongly in the early summer when the sharks are youngest, suggesting that they are seeking refuge from predators (mostly larger sharks) in numbers.[12] Predator avoidance may also be the reason why juvenile blacktips do not congregate in the areas of highest prey density in the bay.[13] Adults have no known predators.[2] Known parasites of the blacktip shark include the copepods Pandarus sinuatus and P. smithii, and the monogeneans Dermophthirius penneri and Dionchus spp., which attach the shark's skin.[2][14][15] This species is also parasitized by nematodes in the family Philometridae, which infest the ovaries.[16]

Behaviour

Blacktip sharks are social and usually found in groups.

Like the spinner shark, the blacktip shark is known to leap out of the water and spin three or four times about its axis before landing. Some of these jumps are the end product of feeding runs, in which the shark corkscrews vertically through schools of small fish and its momentum launches it into the air.[3] Observations in the Bahamas suggest that blacktip sharks may also jump out of the water to dislodge attached sharksuckers (Echeneis naucrates), which irritate the shark's skin and compromise its hydrodynamic shape.[17] The speed attained by the shark during these jumps has been estimated to average 6.3 m/s (21 ft/s).[18]

Blacktip sharks have a timid disposition and consistently lose out to Galapagos sharks (C. galapagensis) and silvertip sharks (C. albimarginatus) of equal size when competing for food.[1] If threatened or challenged, they may perform an agonistic display: the shark swims towards the threat and then turns away, while rolling from side to side, lowering its pectoral fins, tilting its head and tail upwards, and making sideways biting motions. The entire sequence lasts around 25 seconds. This behavior is similar to the actions of a shark attempting to move a sharksucker; one of these behaviors possibly is derived from the other.[19]

Feeding

Fish make up some 90% of the blacktip shark's diet.[20] A wide variety of fish have been recorded as prey for this species: sardines, herring, anchovies, ladyfish, sea catfish, cornetfish, flatfish, threadfins, mullet, mackerel, jacks, groupers, snook, porgies, mojarras, emperors, grunts, butterfish, tilapia, triggerfish, boxfish, and porcupinefish. They also feed on rays and skates, as well as smaller sharks such as smoothhounds and sharpnose sharks. Crustaceans and cephalopods are occasionally taken.[1] In the Gulf of Mexico, the most important prey of the blacktip shark is the Gulf menhaden (Brevoortia patronus), followed by the Atlantic croaker (Micropogonias undulatus).[20] Off South Africa, jacks and herring are the most important prey.[21] Hunting peaks at dawn and dusk.[20] The excitability and sociability of blacktip sharks makes them prone to feeding frenzies when large quantities of food are suddenly available, such as when fishing vessels dump their refuse overboard.[1]

Life history

As with other requiem sharks, the blacktip shark exhibits vivipary. Females typically give birth to four to seven (range one to 10) pups every other year, making use of shallow coastal nurseries that offer plentiful food and fewer predators.[1] Known nurseries include Pine Island Sound, Terra Ceia Bay, and Yankeetown along the Gulf Coast of Florida, Bulls Bay on the coast of South Carolina, and Pontal do Paraná on the coast of Brazil.[22][23] Although adult blacktip sharks are highly mobile and disperse over long distances, they are philopatric and return to their original nursery areas to give birth. This results in a series of genetically distinct breeding stocks that overlap in geographic range.[22][24]

Mating occurs from spring to early summer, and the young are born around the same time the following year after a gestation period of 10–12 months.[1] Females have one functional ovary and two functional uteri; each uterus is separated into compartments with a single embryo inside each.[25] The embryos are initially sustained by a yolk sac; in the 10th or 11th week of gestation, when the embryo measures 18–19 cm long (7.1–7.5 in), the supply of yolk is exhausted and the yolk sac develops into a placental connection that sustains the embryo until birth.[11] The length at birth is 55–60 cm (22–24 in) off the eastern United States and 61–65 cm (24–26 in) off North Africa.[11][25] The mortality rate in the first 15 months of life is 61–91%, with major threats being predation and starvation.[26] The young remain in the nurseries until their first fall, when they migrate to their wintering grounds.[11]

The growth rate of this species slows with age: 25–30 cm (9.8–11.8 in) in the first six months, then 20 cm (7.9 in) a year until the second year, then 10 cm (3.9 in) a year until maturation, then 5 cm (2.0 in) a year for adults.[27][28] The size at maturity varies geographically: males and females mature at 1.4–1.5 m (4.6–4.9 ft) and 1.6 m (5.2 ft), respectively, in the northeastern Atlantic,[11] 1.3–1.4 m (4.3–4.6 ft) and 1.5–1.6 m (4.9–5.2 ft), respectively, in the Gulf of Mexico,[27][29] 1.5 and 1.6 m (4.9 and 5.2 ft) respectively off South Africa,[30] and 1.7 and 1.8 m (5.6 and 5.9 ft), respectively, off North Africa.[25] The age at maturation is 4–5 years for males and 7–8 years for females.[27][29] The lifespan is at least 12 years.[1]

In 2007, a 9-year-old female blacktip shark at the Virginia Aquarium and Marine Science Center was found to be pregnant with a single near-term female pup, despite having never mated with a male. Genetic analysis confirmed that her offspring was the product of automictic parthenogenesis, a form of asexual reproduction in which an ovum merges with a polar body to form a zygote without fertilization. Along with an earlier case of parthenogenesis in the bonnethead (Sphyrna tiburo), this event suggests that asexual reproduction may be more widespread in sharks than previously thought.[31]

Human interactions

The blacktip shark usually poses little danger to divers.

Blacktip sharks showing curiosity towards divers has been reported, but they remain at a safe distance. Under most circumstances, these timid sharks are not regarded as highly dangerous to humans. However, they may become aggressive in the presence of food, and their size and speed invite respect.[1] As of 2008, the International Shark Attack File lists 28 unprovoked attacks (one fatal) and 13 provoked attacks by this species.[32] Blacktip sharks are responsible annually for 16% of the shark attacks around Florida. Most attacks by this species result in only minor wounds.[2]

As one of the most common large sharks in coastal waters, the blacktip shark is caught in large numbers by commercial fisheries throughout the world, using longlines, fixed-bottom nets, bottom trawls, and hook-and-line. The meat is of high quality and marketed fresh, frozen, or dried and salted. In addition, the fins are used for shark fin soup, the skin for leather, the liver oil for vitamins, and the carcasses for fishmeal.[1] Blacktip sharks are one of the most important species to the northwestern Atlantic shark fishery, second only to the sandbar shark (C. plumbeus). The flesh is considered superior to that of the sandbar shark, resulting in the sandbar and other requiem shark species being sold under the name "blacktip shark" in the United States. The blacktip shark is also very significant to Indian and Mexican fisheries, and is caught in varying numbers by fisheries in the Mediterranean and South China Seas, and off northern Australia.[28]

The blacktip shark is popular with recreational anglers in Florida, the Caribbean, and South Africa. It is listed as a game fish by the International Game Fish Association. Once hooked, this species is a strong, steady fighter that sometimes jumps out of the water.[2] Since 1995, the number of blacktip sharks taken by recreational anglers in the United States has approached or surpassed the number taken by commercial fishing.[28] The International Union for Conservation of Nature has assessed the blacktip shark as Near Threatened, as its low reproductive rate renders it vulnerable to overfishing.[33] The United States and Australia are the only two countries that manage fisheries catching blacktip sharks. In both cases, regulation occurs under umbrella management schemes for multiple shark species, such as that for the large coastal sharks category of the US National Marine Fisheries Service Atlantic shark Fisheries Management Plan. No conservation plans specifically for this species have been implemented.[28]

References

  1. ^ a b c d e f g h i j k l m n o Compagno, L.J.V. (1984). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. pp. 481–483. ISBN 92-5-101384-5. 
  2. ^ a b c d e f Curtis, T. Biological Profiles: Blacktip Shark. Florida Museum of Natural History Ichthyology Department. Retrieved on April 27, 2009.
  3. ^ a b c d Ebert, D.A. (2003). Sharks, Rays, and Chimaeras of California. London: University of California Press. pp. 156–157. ISBN 0-520-23484-7. 
  4. ^ a b c Froese, Rainer and Pauly, Daniel, eds. (2009). "Carcharhinus limbatus" in FishBase. April 2009 version.
  5. ^ Dosay-Akbulut, M. (2008). "The phylogenetic relationship within the genus Carcharhinus". Comptes Rendus Biologies. 331 (7): 500–509. doi:10.1016/j.crvi.2008.04.001. PMID 18558373. 
  6. ^ Keeney, D.B. & Heist, E.J. (October 2006). "Worldwide phylogeography of the blacktip shark (Carcharhinus limbatus) inferred from mitochondrial DNA reveals isolation of western Atlantic populations coupled with recent Pacific dispersal". Molecular Ecology. 15 (12): 3669–3679. doi:10.1111/j.1365-294X.2006.03036.x. PMID 17032265. 
  7. ^ Benson. R.N., ed. (1998). Geology and Paleontology of the Lower Miocene Pollack Farm Fossil Site, Delaware: Delaware Geological Survey Special Publication No. 21. Delaware Natural History Survey. pp. 133–139. 
  8. ^ Brown, R.C. (2008). Florida's Fossils: Guide to Location, Identification, and Enjoyment (third ed.). Pineapple Press Inc. p. 100. ISBN 1-56164-409-9. 
  9. ^ Martin, R.A. Albinism in Sharks. ReefQuest Centre for Shark Research. Retrieved on April 28, 2009.
  10. ^ Yano, Kazunari; Morrissey, John F. (1999-06-01). "Confirmation of blacktip shark,Carcharhinus limbatus, in the Ryukyu Islands and notes on possible absence ofC. melanopterus in Japanese waters". Ichthyological Research. 46 (2): 193–198. doi:10.1007/BF02675438. ISSN 1341-8998. 
  11. ^ a b c d e Castro, J.I. (November 1996). "Biology of the blacktip shark, Carcharhinus limbatus, off the southeastern United States". Bulletin of Marine Science. 59 (3): 508–522. 
  12. ^ Heupel, M.R. & Simpfendorfer, C.A. (2005). "Quantitative analysis of aggregation behavior in juvenile blacktip sharks". Marine Biology. 147 (5): 1239–1249. doi:10.1007/s00227-005-0004-7. 
  13. ^ Heupel, M.R. & Hueter, R.E. (2002). "The importance of prey density in relation to the movement patterns of juvenile sharks within a coastal nursery area". Marine and Freshwater Research. 53 (2): 543–550. doi:10.1071/MF01132. 
  14. ^ Bullard, S.A.; Frasca, A. (Jr.) & Benz, G.W. (June 2000). "Skin Lesions Caused by Dermophthirius penneri (Monogenea: Microbothriidae) on Wild-Caught Blacktip Sharks (Carcharhinus limbatus)". Journal of Parasitology. 86 (3): 618–622. doi:10.1645/0022-3395(2000)086[0618:SLCBDP]2.0.CO;2. PMID 10864264. 
  15. ^ Bullard, S.A.; Benz, G.W. & Braswell, J.S. (2000). "Dionchus postoncomiracidia (Monogenea: Dionchidae) from the skin of blacktip sharks, Carcharhinus limbatus (Carcharhinidae)". Journal of Parasitology. 86 (2): 245–250. doi:10.1645/0022-3395(2000)086[0245:DPMDFT]2.0.CO;2. JSTOR 3284763. PMID 10780540. 
  16. ^ Rosa-Molinar, E. & Williams, C.S. (1983). "Larval nematodes (Philometridae) in granulomas in ovaries of blacktip sharks, Carcharhinus limbatus (Valenciennes)". Journal of Wildlife Diseases. 19 (3): 275–277. doi:10.7589/0090-3558-19.3.275. PMID 6644926. 
  17. ^ Riner, E.K. & Brijnnschweiler, J.M. (2003). "Do sharksuckers, Echeneis naucrates, induce jump behaviour in blacktip sharks, Carcharhinus limbatus?". Marine and Freshwater Behaviour and Physiology. 36 (2): 111–113. doi:10.1080/1023624031000119584. 
  18. ^ Brunnschweiler, J.M. (2005). "Water-escape velocities in jumping blacktip sharks". Journal of the Royal Society Interface. 2 (4): 389–391. doi:10.1098/rsif.2005.0047. PMC 1578268Freely accessible. PMID 16849197. 
  19. ^ Ritter, E.K. & Godknecht, A.J. (February 1, 2000). Ross, S. T., ed. "Agonistic Displays in the Blacktip Shark (Carcharhinus limbatus)". Copeia. 2000 (1): 282–284. doi:10.1643/0045-8511(2000)2000[0282:ADITBS]2.0.CO;2. JSTOR 1448264. 
  20. ^ a b c Barry, K.P. (2002). Feeding habits of blacktip sharks, Carcharhinus limbatus, and Atlantic sharpnose sharks, Rhizoprionodon terraenovae, in Louisiana coastal waters. MS thesis, Louisiana State University, Baton Rouge.
  21. ^ Dudley, S.F.J. & Cliff, G. (1993). "Sharks caught in the protective gill nets off Natal, South Africa. 7. The blacktip shark Carcharhinus limbatus (Valenciennes)". African Journal of Marine Science. 13: 237–254. doi:10.2989/025776193784287356. 
  22. ^ a b Keeney, D.B.; Heupel, M.; Hueter, R.E. & Heist, E.J. (2003). "Genetic heterogeneity among blacktip shark, Carcharhinus limbatus, continental nurseries along the U.S. Atlantic and Gulf of Mexico". Marine Biology. 143 (6): 1039–1046. doi:10.1007/s00227-003-1166-9. 
  23. ^ Bornatowski, H. (2008). "A parturition and nursery area for Carcharhinus limbatus (Elasmobranchii, Carcharhinidae) off the coast of Paraná, Brazil". Brazilian Journal of Oceanography. 56 (4): 317–319. doi:10.1590/s1679-87592008000400008. 
  24. ^ Keeney, D.B.; Heupel, M.R.; Hueter, R.E. & Heist, E.J. (2005). "Microsatellite and mitochondrial DNA analyses of the genetic structure of blacktip shark (Carcharhinus limbatus) nurseries in the northwestern Atlantic, Gulf of Mexico, and Caribbean Sea". Molecular Ecology. 14 (7): 1911–1923. doi:10.1111/j.1365-294X.2005.02549.x. PMID 15910315. 
  25. ^ a b c Capapé, C.H.; Seck, A.A.; Diatta, Y.; Reynaud, C.H.; Hemida, F. & Zaouali, J. (2004). "Reproductive biology of the blacktip shark, Carcharhinus limbatus (Chondrichthyes: Carcharhinidae) off West and North African Coasts" (PDF). Cybium. 28 (4): 275–284. 
  26. ^ Heupel, M.R. & Simpfendorfer, C.A. (2002). "Estimation of mortality of juvenile blacktip sharks, Carcharhinus limbatus, within a nursery area using telemetry data". Canadian Journal of Fisheries and Aquatic Sciences. 59 (4): 624–632. doi:10.1139/f02-036. 
  27. ^ a b c Branstetter, S. (December 9, 1987). "Age and Growth Estimates for Blacktip, Carcharhinus limbatus, and Spinner, C. brevipinna, Sharks from the Northwestern Gulf of Mexico". Copeia. American Society of Ichthyologists and Herpetologists. 1987 (4): 964–974. doi:10.2307/1445560. JSTOR 1445560. 
  28. ^ a b c d Fowler, S.L.; Cavanagh, R.D.; Camhi, M.; Burgess, G.H.; Cailliet, G.M.; Fordham, S.V.; Simpfendorfer, C.A. & Musick, J.A. (2005). Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. International Union for Conservation of Nature and Natural Resources. pp. 106–109, 293–295. ISBN 2-8317-0700-5. 
  29. ^ a b Killam, K.A. & Parsons, G.R. (May 1989). "Age and Growth of the Blacktip Shark, Carcharhinus limbatus, near Tampa Bay" (PDF). Florida Fishery Bulletin. 87: 845–857. 
  30. ^ Wintner, S.P. & Cliff, G. (1996). "Age and growth determination of the blacktip shark, Carcharhinus limbatus, from the east coast of South Africa" (PDF). Fishery Bulletin. 94 (1): 135–144. 
  31. ^ Chapman, D.D.; Firchau, B. & Shivji, M.S. (2008). "Parthenogenesis in a large-bodied requiem shark, the blacktip Carcharhinus limbatus". Journal of Fish Biology. 73 (6): 1473–1477. doi:10.1111/j.1095-8649.2008.02018.x. 
  32. ^ ISAF Statistics on Attacking Species of Shark. International Shark Attack File, Florida Museum of Natural History, University of Florida. Retrieved on April 22, 2009.
  33. ^ Musick, J.A.; Fowler, S. (2000). "Carcharhinus limbatus". IUCN Red List of Threatened Species. Version 2007. International Union for Conservation of Nature. Retrieved April 27, 2009. 
source: http://en.wikipedia.org/wiki/Blacktip_shark

Blacktip Shark 2

Blacktip Shark 2 by Inked Animal

Blacktip Shark | Carcharhinus limbatus



Blacktip Shark info via Wikipedia:

Not to be confused with the blacktip reef shark, Carcharhinus melanopterus.
Blacktip shark
Carcharhinus limbatus (2).jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Carcharhinus
Species: C. limbatus
Binomial name
Carcharhinus limbatus
(J. P. Müller & Henle, 1839)
Carcharhinus limbatus distmap.png
Range of the blacktip shark
Synonyms

Carcharias abbreviatus Klunzinger, 1871
Carcharias aethalorus Jordan & Gilbert, 1882
Carcharias ehrenbergi Klunzinger, 1871
Carcharias maculipinna Günther, 1868
Carcharias microps Lowe, 1841
Carcharias muelleri Steindachner, 1867
Carcharias phorcys Jordan & Evermann, 1903
Carcharias pleurotaenia Bleeker, 1852
Carcharhinus natator Meek & Hildebrand, 1923

The blacktip shark (Carcharhinus limbatus) is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of 1.5 m (4.9 ft).

Swift, energetic piscivores, blacktip sharks are known to make spinning leaps out of the water while attacking schools of small fish. Their demeanor has been described as "timid" compared to other large requiem sharks. Both juveniles and adults form groups of varying size. Like other members of its family, the blacktip shark is viviparous; females bear one to 10 pups every other year. Young blacktip sharks spend the first months of their lives in shallow nurseries, and grown females return to the nurseries where they were born to give birth themselves. In the absence of males, females are also capable of asexual reproduction.

Normally wary of humans, blacktip sharks can become aggressive in the presence of food and have been responsible for a number of attacks on people. This species is of importance to both commercial and recreational fisheries across many parts of its range, with its meat, skin, fins, and liver oil used. It has been assessed as Near Threatened by the IUCN, on the basis of its low reproductive rate and high value to fishers.

Taxonomy

The blacktip shark was first described by French zoologist Achille Valenciennes as Carcharias (Prionodon) limbatus in Johannes Müller and Friedrich Henle's 1839 Systematische Beschreibung der Plagiostomen. The type specimens were two individuals caught off Martinique, both of which have since been lost. Later authors moved this species to the genus Carcharhinus.[1][2] The specific epithet limbatus is Latin for "bordered", referring to the black edges of this shark's fins.[3] Other common names used for the blacktip shark include blackfin shark, blacktip whaler, common or small blacktip shark, grey shark, and spotfin ground shark.[4]

Phylogeny and evolution

The closest relatives of the blacktip shark were originally thought to be the graceful shark (C. amblyrhynchoides) and the spinner shark (C. brevipinna), due to similarities in morphology and behavior. However, this interpretation has not been borne out by studies of mitochondrial and ribosomal DNA, which instead suggest affinity with the blacknose shark (C. acronotus). More work is required to fully resolve the relationship between the blacktip shark and other Carcharhinus species.[5]

Analysis of mitochondrial DNA has also revealed two distinct lineages within this species, one occupying the western Atlantic and the other occupying the eastern Atlantic, Indian, and Pacific Oceans. This suggests that Indo-Pacific blacktip sharks are descended from those in the eastern Atlantic, while the western Atlantic sharks became isolated by the widening Atlantic Ocean on one side and the formation of the Isthmus of Panama on the other. Blacktip sharks from these two regions differ in morphology, coloration, and life history characteristics, and the eastern Atlantic lineage may merit species status.[6] Fossil teeth belonging to this species have been found in Early Miocene (23–16 Ma) deposits in Delaware and Florida.[7][8]

Description

The blacktip shark has a robust, streamlined body with a long, pointed snout and relatively small eyes. The five pairs of gill slits are longer than those of similar requiem shark species.[1] The jaws contain 15 tooth rows on either side, with two symphysial teeth (at the jaw midline) in the upper jaw and one symphysial tooth in the lower jaw. The teeth are broad-based with a high, narrow cusp and serrated edges.[2] The first dorsal fin is tall and falcate (sickle-shaped) with a short free rear tip; no ridge runs between the first and second dorsal fins. The large pectoral fins are falcate and pointed.[1]

The coloration is gray to brown above and white below, with a conspicuous white stripe running along the sides. The pectoral fins, second dorsal fin, and the lower lobe of the caudal fin usually have black tips. The pelvic fins and rarely the anal fin may also be black-tipped. The first dorsal fin and the upper lobe of the caudal fin typically have black edges.[1] Some larger individuals have unmarked or nearly unmarked fins.[3] Blacktip sharks can temporarily lose almost all their colors during blooms, or "whitings", of coccolithophores.[9] This species attains a maximum known length of 2.8 m (9.2 ft), though 1.5 m (4.9 ft) is more typical, and a maximum known weight of 123 kg (271 lb).[4]

Distribution and habitat

A blacktip shark swimming in murky water off Oahu, Hawaii

The blacktip shark has a worldwide distribution in tropical and subtropical waters. In the Atlantic, it is found from Massachusetts to Brazil, including the Gulf of Mexico and the Caribbean Sea, and from the Mediterranean Sea, Madeira, and the Canary Islands to the Democratic Republic of the Congo. It occurs all around the periphery of the Indian Ocean, from South Africa and Madagascar to the Arabian Peninsula and the Indian subcontinent, to Southeast Asia. In the western Pacific, it is found from the Ryukyu Islands of Japan[10] to northern Australia, including southern China, the Philippines and Indonesia. In the eastern Pacific, it occurs from Baja California to Peru. It has also been reported at a number of Pacific islands, including New Caledonia, Tahiti, the Marquesas, Hawaii, Revillagigedo, and the Galápagos.[1]

Most blacktip sharks are found in water less than 30 m (98 ft) deep over continental and insular shelves, though they may dive to 64 m (210 ft).[4] Favored habitats are muddy bays, island lagoons, and the drop-offs near coral reefs; they are also tolerant of low salinity and enter estuaries and mangrove swamps. Although an individual may be found some distance offshore, blacktip sharks do not inhabit oceanic waters.[1] Seasonal migration has been documented for the population off the east coast of the United States, moving north to North Carolina in the summer and south to Florida in the winter.[11]

Biology and ecology

The blacktip shark is an extremely fast, energetic predator that is usually found in groups of varying size.[3] Segregation by sex and age does not occur; adult males and nonpregnant females are found apart from pregnant females, and both are separated from juveniles.[1] In Terra Ceia Bay, Florida, a nursery area for this species, juvenile blacktips form aggregations during the day and disperse at night. They aggregate most strongly in the early summer when the sharks are youngest, suggesting that they are seeking refuge from predators (mostly larger sharks) in numbers.[12] Predator avoidance may also be the reason why juvenile blacktips do not congregate in the areas of highest prey density in the bay.[13] Adults have no known predators.[2] Known parasites of the blacktip shark include the copepods Pandarus sinuatus and P. smithii, and the monogeneans Dermophthirius penneri and Dionchus spp., which attach the shark's skin.[2][14][15] This species is also parasitized by nematodes in the family Philometridae, which infest the ovaries.[16]

Behaviour

Blacktip sharks are social and usually found in groups.

Like the spinner shark, the blacktip shark is known to leap out of the water and spin three or four times about its axis before landing. Some of these jumps are the end product of feeding runs, in which the shark corkscrews vertically through schools of small fish and its momentum launches it into the air.[3] Observations in the Bahamas suggest that blacktip sharks may also jump out of the water to dislodge attached sharksuckers (Echeneis naucrates), which irritate the shark's skin and compromise its hydrodynamic shape.[17] The speed attained by the shark during these jumps has been estimated to average 6.3 m/s (21 ft/s).[18]

Blacktip sharks have a timid disposition and consistently lose out to Galapagos sharks (C. galapagensis) and silvertip sharks (C. albimarginatus) of equal size when competing for food.[1] If threatened or challenged, they may perform an agonistic display: the shark swims towards the threat and then turns away, while rolling from side to side, lowering its pectoral fins, tilting its head and tail upwards, and making sideways biting motions. The entire sequence lasts around 25 seconds. This behavior is similar to the actions of a shark attempting to move a sharksucker; one of these behaviors possibly is derived from the other.[19]

Feeding

Fish make up some 90% of the blacktip shark's diet.[20] A wide variety of fish have been recorded as prey for this species: sardines, herring, anchovies, ladyfish, sea catfish, cornetfish, flatfish, threadfins, mullet, mackerel, jacks, groupers, snook, porgies, mojarras, emperors, grunts, butterfish, tilapia, triggerfish, boxfish, and porcupinefish. They also feed on rays and skates, as well as smaller sharks such as smoothhounds and sharpnose sharks. Crustaceans and cephalopods are occasionally taken.[1] In the Gulf of Mexico, the most important prey of the blacktip shark is the Gulf menhaden (Brevoortia patronus), followed by the Atlantic croaker (Micropogonias undulatus).[20] Off South Africa, jacks and herring are the most important prey.[21] Hunting peaks at dawn and dusk.[20] The excitability and sociability of blacktip sharks makes them prone to feeding frenzies when large quantities of food are suddenly available, such as when fishing vessels dump their refuse overboard.[1]

Life history

As with other requiem sharks, the blacktip shark exhibits vivipary. Females typically give birth to four to seven (range one to 10) pups every other year, making use of shallow coastal nurseries that offer plentiful food and fewer predators.[1] Known nurseries include Pine Island Sound, Terra Ceia Bay, and Yankeetown along the Gulf Coast of Florida, Bulls Bay on the coast of South Carolina, and Pontal do Paraná on the coast of Brazil.[22][23] Although adult blacktip sharks are highly mobile and disperse over long distances, they are philopatric and return to their original nursery areas to give birth. This results in a series of genetically distinct breeding stocks that overlap in geographic range.[22][24]

Mating occurs from spring to early summer, and the young are born around the same time the following year after a gestation period of 10–12 months.[1] Females have one functional ovary and two functional uteri; each uterus is separated into compartments with a single embryo inside each.[25] The embryos are initially sustained by a yolk sac; in the 10th or 11th week of gestation, when the embryo measures 18–19 cm long (7.1–7.5 in), the supply of yolk is exhausted and the yolk sac develops into a placental connection that sustains the embryo until birth.[11] The length at birth is 55–60 cm (22–24 in) off the eastern United States and 61–65 cm (24–26 in) off North Africa.[11][25] The mortality rate in the first 15 months of life is 61–91%, with major threats being predation and starvation.[26] The young remain in the nurseries until their first fall, when they migrate to their wintering grounds.[11]

The growth rate of this species slows with age: 25–30 cm (9.8–11.8 in) in the first six months, then 20 cm (7.9 in) a year until the second year, then 10 cm (3.9 in) a year until maturation, then 5 cm (2.0 in) a year for adults.[27][28] The size at maturity varies geographically: males and females mature at 1.4–1.5 m (4.6–4.9 ft) and 1.6 m (5.2 ft), respectively, in the northeastern Atlantic,[11] 1.3–1.4 m (4.3–4.6 ft) and 1.5–1.6 m (4.9–5.2 ft), respectively, in the Gulf of Mexico,[27][29] 1.5 and 1.6 m (4.9 and 5.2 ft) respectively off South Africa,[30] and 1.7 and 1.8 m (5.6 and 5.9 ft), respectively, off North Africa.[25] The age at maturation is 4–5 years for males and 7–8 years for females.[27][29] The lifespan is at least 12 years.[1]

In 2007, a 9-year-old female blacktip shark at the Virginia Aquarium and Marine Science Center was found to be pregnant with a single near-term female pup, despite having never mated with a male. Genetic analysis confirmed that her offspring was the product of automictic parthenogenesis, a form of asexual reproduction in which an ovum merges with a polar body to form a zygote without fertilization. Along with an earlier case of parthenogenesis in the bonnethead (Sphyrna tiburo), this event suggests that asexual reproduction may be more widespread in sharks than previously thought.[31]

Human interactions

The blacktip shark usually poses little danger to divers.

Blacktip sharks showing curiosity towards divers has been reported, but they remain at a safe distance. Under most circumstances, these timid sharks are not regarded as highly dangerous to humans. However, they may become aggressive in the presence of food, and their size and speed invite respect.[1] As of 2008, the International Shark Attack File lists 28 unprovoked attacks (one fatal) and 13 provoked attacks by this species.[32] Blacktip sharks are responsible annually for 16% of the shark attacks around Florida. Most attacks by this species result in only minor wounds.[2]

As one of the most common large sharks in coastal waters, the blacktip shark is caught in large numbers by commercial fisheries throughout the world, using longlines, fixed-bottom nets, bottom trawls, and hook-and-line. The meat is of high quality and marketed fresh, frozen, or dried and salted. In addition, the fins are used for shark fin soup, the skin for leather, the liver oil for vitamins, and the carcasses for fishmeal.[1] Blacktip sharks are one of the most important species to the northwestern Atlantic shark fishery, second only to the sandbar shark (C. plumbeus). The flesh is considered superior to that of the sandbar shark, resulting in the sandbar and other requiem shark species being sold under the name "blacktip shark" in the United States. The blacktip shark is also very significant to Indian and Mexican fisheries, and is caught in varying numbers by fisheries in the Mediterranean and South China Seas, and off northern Australia.[28]

The blacktip shark is popular with recreational anglers in Florida, the Caribbean, and South Africa. It is listed as a game fish by the International Game Fish Association. Once hooked, this species is a strong, steady fighter that sometimes jumps out of the water.[2] Since 1995, the number of blacktip sharks taken by recreational anglers in the United States has approached or surpassed the number taken by commercial fishing.[28] The International Union for Conservation of Nature has assessed the blacktip shark as Near Threatened, as its low reproductive rate renders it vulnerable to overfishing.[33] The United States and Australia are the only two countries that manage fisheries catching blacktip sharks. In both cases, regulation occurs under umbrella management schemes for multiple shark species, such as that for the large coastal sharks category of the US National Marine Fisheries Service Atlantic shark Fisheries Management Plan. No conservation plans specifically for this species have been implemented.[28]

References

  1. ^ a b c d e f g h i j k l m n o Compagno, L.J.V. (1984). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. pp. 481–483. ISBN 92-5-101384-5. 
  2. ^ a b c d e f Curtis, T. Biological Profiles: Blacktip Shark. Florida Museum of Natural History Ichthyology Department. Retrieved on April 27, 2009.
  3. ^ a b c d Ebert, D.A. (2003). Sharks, Rays, and Chimaeras of California. London: University of California Press. pp. 156–157. ISBN 0-520-23484-7. 
  4. ^ a b c Froese, Rainer and Pauly, Daniel, eds. (2009). "Carcharhinus limbatus" in FishBase. April 2009 version.
  5. ^ Dosay-Akbulut, M. (2008). "The phylogenetic relationship within the genus Carcharhinus". Comptes Rendus Biologies. 331 (7): 500–509. doi:10.1016/j.crvi.2008.04.001. PMID 18558373. 
  6. ^ Keeney, D.B. & Heist, E.J. (October 2006). "Worldwide phylogeography of the blacktip shark (Carcharhinus limbatus) inferred from mitochondrial DNA reveals isolation of western Atlantic populations coupled with recent Pacific dispersal". Molecular Ecology. 15 (12): 3669–3679. doi:10.1111/j.1365-294X.2006.03036.x. PMID 17032265. 
  7. ^ Benson. R.N., ed. (1998). Geology and Paleontology of the Lower Miocene Pollack Farm Fossil Site, Delaware: Delaware Geological Survey Special Publication No. 21. Delaware Natural History Survey. pp. 133–139. 
  8. ^ Brown, R.C. (2008). Florida's Fossils: Guide to Location, Identification, and Enjoyment (third ed.). Pineapple Press Inc. p. 100. ISBN 1-56164-409-9. 
  9. ^ Martin, R.A. Albinism in Sharks. ReefQuest Centre for Shark Research. Retrieved on April 28, 2009.
  10. ^ Yano, Kazunari; Morrissey, John F. (1999-06-01). "Confirmation of blacktip shark,Carcharhinus limbatus, in the Ryukyu Islands and notes on possible absence ofC. melanopterus in Japanese waters". Ichthyological Research. 46 (2): 193–198. doi:10.1007/BF02675438. ISSN 1341-8998. 
  11. ^ a b c d e Castro, J.I. (November 1996). "Biology of the blacktip shark, Carcharhinus limbatus, off the southeastern United States". Bulletin of Marine Science. 59 (3): 508–522. 
  12. ^ Heupel, M.R. & Simpfendorfer, C.A. (2005). "Quantitative analysis of aggregation behavior in juvenile blacktip sharks". Marine Biology. 147 (5): 1239–1249. doi:10.1007/s00227-005-0004-7. 
  13. ^ Heupel, M.R. & Hueter, R.E. (2002). "The importance of prey density in relation to the movement patterns of juvenile sharks within a coastal nursery area". Marine and Freshwater Research. 53 (2): 543–550. doi:10.1071/MF01132. 
  14. ^ Bullard, S.A.; Frasca, A. (Jr.) & Benz, G.W. (June 2000). "Skin Lesions Caused by Dermophthirius penneri (Monogenea: Microbothriidae) on Wild-Caught Blacktip Sharks (Carcharhinus limbatus)". Journal of Parasitology. 86 (3): 618–622. doi:10.1645/0022-3395(2000)086[0618:SLCBDP]2.0.CO;2. PMID 10864264. 
  15. ^ Bullard, S.A.; Benz, G.W. & Braswell, J.S. (2000). "Dionchus postoncomiracidia (Monogenea: Dionchidae) from the skin of blacktip sharks, Carcharhinus limbatus (Carcharhinidae)". Journal of Parasitology. 86 (2): 245–250. doi:10.1645/0022-3395(2000)086[0245:DPMDFT]2.0.CO;2. JSTOR 3284763. PMID 10780540. 
  16. ^ Rosa-Molinar, E. & Williams, C.S. (1983). "Larval nematodes (Philometridae) in granulomas in ovaries of blacktip sharks, Carcharhinus limbatus (Valenciennes)". Journal of Wildlife Diseases. 19 (3): 275–277. doi:10.7589/0090-3558-19.3.275. PMID 6644926. 
  17. ^ Riner, E.K. & Brijnnschweiler, J.M. (2003). "Do sharksuckers, Echeneis naucrates, induce jump behaviour in blacktip sharks, Carcharhinus limbatus?". Marine and Freshwater Behaviour and Physiology. 36 (2): 111–113. doi:10.1080/1023624031000119584. 
  18. ^ Brunnschweiler, J.M. (2005). "Water-escape velocities in jumping blacktip sharks". Journal of the Royal Society Interface. 2 (4): 389–391. doi:10.1098/rsif.2005.0047. PMC 1578268Freely accessible. PMID 16849197. 
  19. ^ Ritter, E.K. & Godknecht, A.J. (February 1, 2000). Ross, S. T., ed. "Agonistic Displays in the Blacktip Shark (Carcharhinus limbatus)". Copeia. 2000 (1): 282–284. doi:10.1643/0045-8511(2000)2000[0282:ADITBS]2.0.CO;2. JSTOR 1448264. 
  20. ^ a b c Barry, K.P. (2002). Feeding habits of blacktip sharks, Carcharhinus limbatus, and Atlantic sharpnose sharks, Rhizoprionodon terraenovae, in Louisiana coastal waters. MS thesis, Louisiana State University, Baton Rouge.
  21. ^ Dudley, S.F.J. & Cliff, G. (1993). "Sharks caught in the protective gill nets off Natal, South Africa. 7. The blacktip shark Carcharhinus limbatus (Valenciennes)". African Journal of Marine Science. 13: 237–254. doi:10.2989/025776193784287356. 
  22. ^ a b Keeney, D.B.; Heupel, M.; Hueter, R.E. & Heist, E.J. (2003). "Genetic heterogeneity among blacktip shark, Carcharhinus limbatus, continental nurseries along the U.S. Atlantic and Gulf of Mexico". Marine Biology. 143 (6): 1039–1046. doi:10.1007/s00227-003-1166-9. 
  23. ^ Bornatowski, H. (2008). "A parturition and nursery area for Carcharhinus limbatus (Elasmobranchii, Carcharhinidae) off the coast of Paraná, Brazil". Brazilian Journal of Oceanography. 56 (4): 317–319. doi:10.1590/s1679-87592008000400008. 
  24. ^ Keeney, D.B.; Heupel, M.R.; Hueter, R.E. & Heist, E.J. (2005). "Microsatellite and mitochondrial DNA analyses of the genetic structure of blacktip shark (Carcharhinus limbatus) nurseries in the northwestern Atlantic, Gulf of Mexico, and Caribbean Sea". Molecular Ecology. 14 (7): 1911–1923. doi:10.1111/j.1365-294X.2005.02549.x. PMID 15910315. 
  25. ^ a b c Capapé, C.H.; Seck, A.A.; Diatta, Y.; Reynaud, C.H.; Hemida, F. & Zaouali, J. (2004). "Reproductive biology of the blacktip shark, Carcharhinus limbatus (Chondrichthyes: Carcharhinidae) off West and North African Coasts" (PDF). Cybium. 28 (4): 275–284. 
  26. ^ Heupel, M.R. & Simpfendorfer, C.A. (2002). "Estimation of mortality of juvenile blacktip sharks, Carcharhinus limbatus, within a nursery area using telemetry data". Canadian Journal of Fisheries and Aquatic Sciences. 59 (4): 624–632. doi:10.1139/f02-036. 
  27. ^ a b c Branstetter, S. (December 9, 1987). "Age and Growth Estimates for Blacktip, Carcharhinus limbatus, and Spinner, C. brevipinna, Sharks from the Northwestern Gulf of Mexico". Copeia. American Society of Ichthyologists and Herpetologists. 1987 (4): 964–974. doi:10.2307/1445560. JSTOR 1445560. 
  28. ^ a b c d Fowler, S.L.; Cavanagh, R.D.; Camhi, M.; Burgess, G.H.; Cailliet, G.M.; Fordham, S.V.; Simpfendorfer, C.A. & Musick, J.A. (2005). Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. International Union for Conservation of Nature and Natural Resources. pp. 106–109, 293–295. ISBN 2-8317-0700-5. 
  29. ^ a b Killam, K.A. & Parsons, G.R. (May 1989). "Age and Growth of the Blacktip Shark, Carcharhinus limbatus, near Tampa Bay" (PDF). Florida Fishery Bulletin. 87: 845–857. 
  30. ^ Wintner, S.P. & Cliff, G. (1996). "Age and growth determination of the blacktip shark, Carcharhinus limbatus, from the east coast of South Africa" (PDF). Fishery Bulletin. 94 (1): 135–144. 
  31. ^ Chapman, D.D.; Firchau, B. & Shivji, M.S. (2008). "Parthenogenesis in a large-bodied requiem shark, the blacktip Carcharhinus limbatus". Journal of Fish Biology. 73 (6): 1473–1477. doi:10.1111/j.1095-8649.2008.02018.x. 
  32. ^ ISAF Statistics on Attacking Species of Shark. International Shark Attack File, Florida Museum of Natural History, University of Florida. Retrieved on April 22, 2009.
  33. ^ Musick, J.A.; Fowler, S. (2000). "Carcharhinus limbatus". IUCN Red List of Threatened Species. Version 2007. International Union for Conservation of Nature. Retrieved April 27, 2009. 
source: http://en.wikipedia.org/wiki/Blacktip_shark

Blacktip Shark 1

Blacktip Shark by Inked Animal

Blacktip Shark | Carcharhinus limbatus

 


Blacktip Shark info via Wikipedia:

Not to be confused with the blacktip reef shark, Carcharhinus melanopterus.
Blacktip shark
Carcharhinus limbatus (2).jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Carcharhinus
Species: C. limbatus
Binomial name
Carcharhinus limbatus
(J. P. Müller & Henle, 1839)
Carcharhinus limbatus distmap.png
Range of the blacktip shark
Synonyms

Carcharias abbreviatus Klunzinger, 1871
Carcharias aethalorus Jordan & Gilbert, 1882
Carcharias ehrenbergi Klunzinger, 1871
Carcharias maculipinna Günther, 1868
Carcharias microps Lowe, 1841
Carcharias muelleri Steindachner, 1867
Carcharias phorcys Jordan & Evermann, 1903
Carcharias pleurotaenia Bleeker, 1852
Carcharhinus natator Meek & Hildebrand, 1923

The blacktip shark (Carcharhinus limbatus) is a species of requiem shark, and part of the family Carcharhinidae. It is common to coastal tropical and subtropical waters around the world, including brackish habitats. Genetic analyses have revealed substantial variation within this species, with populations from the western Atlantic Ocean isolated and distinct from those in the rest of its range. The blacktip shark has a stout, fusiform body with a pointed snout, long gill slits, and no ridge between the dorsal fins. Most individuals have black tips or edges on the pectoral, dorsal, pelvic, and caudal fins. It usually attains a length of 1.5 m (4.9 ft).

Swift, energetic piscivores, blacktip sharks are known to make spinning leaps out of the water while attacking schools of small fish. Their demeanor has been described as "timid" compared to other large requiem sharks. Both juveniles and adults form groups of varying size. Like other members of its family, the blacktip shark is viviparous; females bear one to 10 pups every other year. Young blacktip sharks spend the first months of their lives in shallow nurseries, and grown females return to the nurseries where they were born to give birth themselves. In the absence of males, females are also capable of asexual reproduction.

Normally wary of humans, blacktip sharks can become aggressive in the presence of food and have been responsible for a number of attacks on people. This species is of importance to both commercial and recreational fisheries across many parts of its range, with its meat, skin, fins, and liver oil used. It has been assessed as Near Threatened by the IUCN, on the basis of its low reproductive rate and high value to fishers.

Taxonomy

The blacktip shark was first described by French zoologist Achille Valenciennes as Carcharias (Prionodon) limbatus in Johannes Müller and Friedrich Henle's 1839 Systematische Beschreibung der Plagiostomen. The type specimens were two individuals caught off Martinique, both of which have since been lost. Later authors moved this species to the genus Carcharhinus.[1][2] The specific epithet limbatus is Latin for "bordered", referring to the black edges of this shark's fins.[3] Other common names used for the blacktip shark include blackfin shark, blacktip whaler, common or small blacktip shark, grey shark, and spotfin ground shark.[4]

Phylogeny and evolution

The closest relatives of the blacktip shark were originally thought to be the graceful shark (C. amblyrhynchoides) and the spinner shark (C. brevipinna), due to similarities in morphology and behavior. However, this interpretation has not been borne out by studies of mitochondrial and ribosomal DNA, which instead suggest affinity with the blacknose shark (C. acronotus). More work is required to fully resolve the relationship between the blacktip shark and other Carcharhinus species.[5]

Analysis of mitochondrial DNA has also revealed two distinct lineages within this species, one occupying the western Atlantic and the other occupying the eastern Atlantic, Indian, and Pacific Oceans. This suggests that Indo-Pacific blacktip sharks are descended from those in the eastern Atlantic, while the western Atlantic sharks became isolated by the widening Atlantic Ocean on one side and the formation of the Isthmus of Panama on the other. Blacktip sharks from these two regions differ in morphology, coloration, and life history characteristics, and the eastern Atlantic lineage may merit species status.[6] Fossil teeth belonging to this species have been found in Early Miocene (23–16 Ma) deposits in Delaware and Florida.[7][8]

Description

The blacktip shark has a robust, streamlined body with a long, pointed snout and relatively small eyes. The five pairs of gill slits are longer than those of similar requiem shark species.[1] The jaws contain 15 tooth rows on either side, with two symphysial teeth (at the jaw midline) in the upper jaw and one symphysial tooth in the lower jaw. The teeth are broad-based with a high, narrow cusp and serrated edges.[2] The first dorsal fin is tall and falcate (sickle-shaped) with a short free rear tip; no ridge runs between the first and second dorsal fins. The large pectoral fins are falcate and pointed.[1]

The coloration is gray to brown above and white below, with a conspicuous white stripe running along the sides. The pectoral fins, second dorsal fin, and the lower lobe of the caudal fin usually have black tips. The pelvic fins and rarely the anal fin may also be black-tipped. The first dorsal fin and the upper lobe of the caudal fin typically have black edges.[1] Some larger individuals have unmarked or nearly unmarked fins.[3] Blacktip sharks can temporarily lose almost all their colors during blooms, or "whitings", of coccolithophores.[9] This species attains a maximum known length of 2.8 m (9.2 ft), though 1.5 m (4.9 ft) is more typical, and a maximum known weight of 123 kg (271 lb).[4]

Distribution and habitat

A blacktip shark swimming in murky water off Oahu, Hawaii

The blacktip shark has a worldwide distribution in tropical and subtropical waters. In the Atlantic, it is found from Massachusetts to Brazil, including the Gulf of Mexico and the Caribbean Sea, and from the Mediterranean Sea, Madeira, and the Canary Islands to the Democratic Republic of the Congo. It occurs all around the periphery of the Indian Ocean, from South Africa and Madagascar to the Arabian Peninsula and the Indian subcontinent, to Southeast Asia. In the western Pacific, it is found from the Ryukyu Islands of Japan[10] to northern Australia, including southern China, the Philippines and Indonesia. In the eastern Pacific, it occurs from Baja California to Peru. It has also been reported at a number of Pacific islands, including New Caledonia, Tahiti, the Marquesas, Hawaii, Revillagigedo, and the Galápagos.[1]

Most blacktip sharks are found in water less than 30 m (98 ft) deep over continental and insular shelves, though they may dive to 64 m (210 ft).[4] Favored habitats are muddy bays, island lagoons, and the drop-offs near coral reefs; they are also tolerant of low salinity and enter estuaries and mangrove swamps. Although an individual may be found some distance offshore, blacktip sharks do not inhabit oceanic waters.[1] Seasonal migration has been documented for the population off the east coast of the United States, moving north to North Carolina in the summer and south to Florida in the winter.[11]

Biology and ecology

The blacktip shark is an extremely fast, energetic predator that is usually found in groups of varying size.[3] Segregation by sex and age does not occur; adult males and nonpregnant females are found apart from pregnant females, and both are separated from juveniles.[1] In Terra Ceia Bay, Florida, a nursery area for this species, juvenile blacktips form aggregations during the day and disperse at night. They aggregate most strongly in the early summer when the sharks are youngest, suggesting that they are seeking refuge from predators (mostly larger sharks) in numbers.[12] Predator avoidance may also be the reason why juvenile blacktips do not congregate in the areas of highest prey density in the bay.[13] Adults have no known predators.[2] Known parasites of the blacktip shark include the copepods Pandarus sinuatus and P. smithii, and the monogeneans Dermophthirius penneri and Dionchus spp., which attach the shark's skin.[2][14][15] This species is also parasitized by nematodes in the family Philometridae, which infest the ovaries.[16]

Behaviour

Blacktip sharks are social and usually found in groups.

Like the spinner shark, the blacktip shark is known to leap out of the water and spin three or four times about its axis before landing. Some of these jumps are the end product of feeding runs, in which the shark corkscrews vertically through schools of small fish and its momentum launches it into the air.[3] Observations in the Bahamas suggest that blacktip sharks may also jump out of the water to dislodge attached sharksuckers (Echeneis naucrates), which irritate the shark's skin and compromise its hydrodynamic shape.[17] The speed attained by the shark during these jumps has been estimated to average 6.3 m/s (21 ft/s).[18]

Blacktip sharks have a timid disposition and consistently lose out to Galapagos sharks (C. galapagensis) and silvertip sharks (C. albimarginatus) of equal size when competing for food.[1] If threatened or challenged, they may perform an agonistic display: the shark swims towards the threat and then turns away, while rolling from side to side, lowering its pectoral fins, tilting its head and tail upwards, and making sideways biting motions. The entire sequence lasts around 25 seconds. This behavior is similar to the actions of a shark attempting to move a sharksucker; one of these behaviors possibly is derived from the other.[19]

Feeding

Fish make up some 90% of the blacktip shark's diet.[20] A wide variety of fish have been recorded as prey for this species: sardines, herring, anchovies, ladyfish, sea catfish, cornetfish, flatfish, threadfins, mullet, mackerel, jacks, groupers, snook, porgies, mojarras, emperors, grunts, butterfish, tilapia, triggerfish, boxfish, and porcupinefish. They also feed on rays and skates, as well as smaller sharks such as smoothhounds and sharpnose sharks. Crustaceans and cephalopods are occasionally taken.[1] In the Gulf of Mexico, the most important prey of the blacktip shark is the Gulf menhaden (Brevoortia patronus), followed by the Atlantic croaker (Micropogonias undulatus).[20] Off South Africa, jacks and herring are the most important prey.[21] Hunting peaks at dawn and dusk.[20] The excitability and sociability of blacktip sharks makes them prone to feeding frenzies when large quantities of food are suddenly available, such as when fishing vessels dump their refuse overboard.[1]

Life history

As with other requiem sharks, the blacktip shark exhibits vivipary. Females typically give birth to four to seven (range one to 10) pups every other year, making use of shallow coastal nurseries that offer plentiful food and fewer predators.[1] Known nurseries include Pine Island Sound, Terra Ceia Bay, and Yankeetown along the Gulf Coast of Florida, Bulls Bay on the coast of South Carolina, and Pontal do Paraná on the coast of Brazil.[22][23] Although adult blacktip sharks are highly mobile and disperse over long distances, they are philopatric and return to their original nursery areas to give birth. This results in a series of genetically distinct breeding stocks that overlap in geographic range.[22][24]

Mating occurs from spring to early summer, and the young are born around the same time the following year after a gestation period of 10–12 months.[1] Females have one functional ovary and two functional uteri; each uterus is separated into compartments with a single embryo inside each.[25] The embryos are initially sustained by a yolk sac; in the 10th or 11th week of gestation, when the embryo measures 18–19 cm long (7.1–7.5 in), the supply of yolk is exhausted and the yolk sac develops into a placental connection that sustains the embryo until birth.[11] The length at birth is 55–60 cm (22–24 in) off the eastern United States and 61–65 cm (24–26 in) off North Africa.[11][25] The mortality rate in the first 15 months of life is 61–91%, with major threats being predation and starvation.[26] The young remain in the nurseries until their first fall, when they migrate to their wintering grounds.[11]

The growth rate of this species slows with age: 25–30 cm (9.8–11.8 in) in the first six months, then 20 cm (7.9 in) a year until the second year, then 10 cm (3.9 in) a year until maturation, then 5 cm (2.0 in) a year for adults.[27][28] The size at maturity varies geographically: males and females mature at 1.4–1.5 m (4.6–4.9 ft) and 1.6 m (5.2 ft), respectively, in the northeastern Atlantic,[11] 1.3–1.4 m (4.3–4.6 ft) and 1.5–1.6 m (4.9–5.2 ft), respectively, in the Gulf of Mexico,[27][29] 1.5 and 1.6 m (4.9 and 5.2 ft) respectively off South Africa,[30] and 1.7 and 1.8 m (5.6 and 5.9 ft), respectively, off North Africa.[25] The age at maturation is 4–5 years for males and 7–8 years for females.[27][29] The lifespan is at least 12 years.[1]

In 2007, a 9-year-old female blacktip shark at the Virginia Aquarium and Marine Science Center was found to be pregnant with a single near-term female pup, despite having never mated with a male. Genetic analysis confirmed that her offspring was the product of automictic parthenogenesis, a form of asexual reproduction in which an ovum merges with a polar body to form a zygote without fertilization. Along with an earlier case of parthenogenesis in the bonnethead (Sphyrna tiburo), this event suggests that asexual reproduction may be more widespread in sharks than previously thought.[31]

Human interactions

The blacktip shark usually poses little danger to divers.

Blacktip sharks showing curiosity towards divers has been reported, but they remain at a safe distance. Under most circumstances, these timid sharks are not regarded as highly dangerous to humans. However, they may become aggressive in the presence of food, and their size and speed invite respect.[1] As of 2008, the International Shark Attack File lists 28 unprovoked attacks (one fatal) and 13 provoked attacks by this species.[32] Blacktip sharks are responsible annually for 16% of the shark attacks around Florida. Most attacks by this species result in only minor wounds.[2]

As one of the most common large sharks in coastal waters, the blacktip shark is caught in large numbers by commercial fisheries throughout the world, using longlines, fixed-bottom nets, bottom trawls, and hook-and-line. The meat is of high quality and marketed fresh, frozen, or dried and salted. In addition, the fins are used for shark fin soup, the skin for leather, the liver oil for vitamins, and the carcasses for fishmeal.[1] Blacktip sharks are one of the most important species to the northwestern Atlantic shark fishery, second only to the sandbar shark (C. plumbeus). The flesh is considered superior to that of the sandbar shark, resulting in the sandbar and other requiem shark species being sold under the name "blacktip shark" in the United States. The blacktip shark is also very significant to Indian and Mexican fisheries, and is caught in varying numbers by fisheries in the Mediterranean and South China Seas, and off northern Australia.[28]

The blacktip shark is popular with recreational anglers in Florida, the Caribbean, and South Africa. It is listed as a game fish by the International Game Fish Association. Once hooked, this species is a strong, steady fighter that sometimes jumps out of the water.[2] Since 1995, the number of blacktip sharks taken by recreational anglers in the United States has approached or surpassed the number taken by commercial fishing.[28] The International Union for Conservation of Nature has assessed the blacktip shark as Near Threatened, as its low reproductive rate renders it vulnerable to overfishing.[33] The United States and Australia are the only two countries that manage fisheries catching blacktip sharks. In both cases, regulation occurs under umbrella management schemes for multiple shark species, such as that for the large coastal sharks category of the US National Marine Fisheries Service Atlantic shark Fisheries Management Plan. No conservation plans specifically for this species have been implemented.[28]

References

  1. ^ a b c d e f g h i j k l m n o Compagno, L.J.V. (1984). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. pp. 481–483. ISBN 92-5-101384-5. 
  2. ^ a b c d e f Curtis, T. Biological Profiles: Blacktip Shark. Florida Museum of Natural History Ichthyology Department. Retrieved on April 27, 2009.
  3. ^ a b c d Ebert, D.A. (2003). Sharks, Rays, and Chimaeras of California. London: University of California Press. pp. 156–157. ISBN 0-520-23484-7. 
  4. ^ a b c Froese, Rainer and Pauly, Daniel, eds. (2009). "Carcharhinus limbatus" in FishBase. April 2009 version.
  5. ^ Dosay-Akbulut, M. (2008). "The phylogenetic relationship within the genus Carcharhinus". Comptes Rendus Biologies. 331 (7): 500–509. doi:10.1016/j.crvi.2008.04.001. PMID 18558373. 
  6. ^ Keeney, D.B. & Heist, E.J. (October 2006). "Worldwide phylogeography of the blacktip shark (Carcharhinus limbatus) inferred from mitochondrial DNA reveals isolation of western Atlantic populations coupled with recent Pacific dispersal". Molecular Ecology. 15 (12): 3669–3679. doi:10.1111/j.1365-294X.2006.03036.x. PMID 17032265. 
  7. ^ Benson. R.N., ed. (1998). Geology and Paleontology of the Lower Miocene Pollack Farm Fossil Site, Delaware: Delaware Geological Survey Special Publication No. 21. Delaware Natural History Survey. pp. 133–139. 
  8. ^ Brown, R.C. (2008). Florida's Fossils: Guide to Location, Identification, and Enjoyment (third ed.). Pineapple Press Inc. p. 100. ISBN 1-56164-409-9. 
  9. ^ Martin, R.A. Albinism in Sharks. ReefQuest Centre for Shark Research. Retrieved on April 28, 2009.
  10. ^ Yano, Kazunari; Morrissey, John F. (1999-06-01). "Confirmation of blacktip shark,Carcharhinus limbatus, in the Ryukyu Islands and notes on possible absence ofC. melanopterus in Japanese waters". Ichthyological Research. 46 (2): 193–198. doi:10.1007/BF02675438. ISSN 1341-8998. 
  11. ^ a b c d e Castro, J.I. (November 1996). "Biology of the blacktip shark, Carcharhinus limbatus, off the southeastern United States". Bulletin of Marine Science. 59 (3): 508–522. 
  12. ^ Heupel, M.R. & Simpfendorfer, C.A. (2005). "Quantitative analysis of aggregation behavior in juvenile blacktip sharks". Marine Biology. 147 (5): 1239–1249. doi:10.1007/s00227-005-0004-7. 
  13. ^ Heupel, M.R. & Hueter, R.E. (2002). "The importance of prey density in relation to the movement patterns of juvenile sharks within a coastal nursery area". Marine and Freshwater Research. 53 (2): 543–550. doi:10.1071/MF01132. 
  14. ^ Bullard, S.A.; Frasca, A. (Jr.) & Benz, G.W. (June 2000). "Skin Lesions Caused by Dermophthirius penneri (Monogenea: Microbothriidae) on Wild-Caught Blacktip Sharks (Carcharhinus limbatus)". Journal of Parasitology. 86 (3): 618–622. doi:10.1645/0022-3395(2000)086[0618:SLCBDP]2.0.CO;2. PMID 10864264. 
  15. ^ Bullard, S.A.; Benz, G.W. & Braswell, J.S. (2000). "Dionchus postoncomiracidia (Monogenea: Dionchidae) from the skin of blacktip sharks, Carcharhinus limbatus (Carcharhinidae)". Journal of Parasitology. 86 (2): 245–250. doi:10.1645/0022-3395(2000)086[0245:DPMDFT]2.0.CO;2. JSTOR 3284763. PMID 10780540. 
  16. ^ Rosa-Molinar, E. & Williams, C.S. (1983). "Larval nematodes (Philometridae) in granulomas in ovaries of blacktip sharks, Carcharhinus limbatus (Valenciennes)". Journal of Wildlife Diseases. 19 (3): 275–277. doi:10.7589/0090-3558-19.3.275. PMID 6644926. 
  17. ^ Riner, E.K. & Brijnnschweiler, J.M. (2003). "Do sharksuckers, Echeneis naucrates, induce jump behaviour in blacktip sharks, Carcharhinus limbatus?". Marine and Freshwater Behaviour and Physiology. 36 (2): 111–113. doi:10.1080/1023624031000119584. 
  18. ^ Brunnschweiler, J.M. (2005). "Water-escape velocities in jumping blacktip sharks". Journal of the Royal Society Interface. 2 (4): 389–391. doi:10.1098/rsif.2005.0047. PMC 1578268Freely accessible. PMID 16849197. 
  19. ^ Ritter, E.K. & Godknecht, A.J. (February 1, 2000). Ross, S. T., ed. "Agonistic Displays in the Blacktip Shark (Carcharhinus limbatus)". Copeia. 2000 (1): 282–284. doi:10.1643/0045-8511(2000)2000[0282:ADITBS]2.0.CO;2. JSTOR 1448264. 
  20. ^ a b c Barry, K.P. (2002). Feeding habits of blacktip sharks, Carcharhinus limbatus, and Atlantic sharpnose sharks, Rhizoprionodon terraenovae, in Louisiana coastal waters. MS thesis, Louisiana State University, Baton Rouge.
  21. ^ Dudley, S.F.J. & Cliff, G. (1993). "Sharks caught in the protective gill nets off Natal, South Africa. 7. The blacktip shark Carcharhinus limbatus (Valenciennes)". African Journal of Marine Science. 13: 237–254. doi:10.2989/025776193784287356. 
  22. ^ a b Keeney, D.B.; Heupel, M.; Hueter, R.E. & Heist, E.J. (2003). "Genetic heterogeneity among blacktip shark, Carcharhinus limbatus, continental nurseries along the U.S. Atlantic and Gulf of Mexico". Marine Biology. 143 (6): 1039–1046. doi:10.1007/s00227-003-1166-9. 
  23. ^ Bornatowski, H. (2008). "A parturition and nursery area for Carcharhinus limbatus (Elasmobranchii, Carcharhinidae) off the coast of Paraná, Brazil". Brazilian Journal of Oceanography. 56 (4): 317–319. doi:10.1590/s1679-87592008000400008. 
  24. ^ Keeney, D.B.; Heupel, M.R.; Hueter, R.E. & Heist, E.J. (2005). "Microsatellite and mitochondrial DNA analyses of the genetic structure of blacktip shark (Carcharhinus limbatus) nurseries in the northwestern Atlantic, Gulf of Mexico, and Caribbean Sea". Molecular Ecology. 14 (7): 1911–1923. doi:10.1111/j.1365-294X.2005.02549.x. PMID 15910315. 
  25. ^ a b c Capapé, C.H.; Seck, A.A.; Diatta, Y.; Reynaud, C.H.; Hemida, F. & Zaouali, J. (2004). "Reproductive biology of the blacktip shark, Carcharhinus limbatus (Chondrichthyes: Carcharhinidae) off West and North African Coasts" (PDF). Cybium. 28 (4): 275–284. 
  26. ^ Heupel, M.R. & Simpfendorfer, C.A. (2002). "Estimation of mortality of juvenile blacktip sharks, Carcharhinus limbatus, within a nursery area using telemetry data". Canadian Journal of Fisheries and Aquatic Sciences. 59 (4): 624–632. doi:10.1139/f02-036. 
  27. ^ a b c Branstetter, S. (December 9, 1987). "Age and Growth Estimates for Blacktip, Carcharhinus limbatus, and Spinner, C. brevipinna, Sharks from the Northwestern Gulf of Mexico". Copeia. American Society of Ichthyologists and Herpetologists. 1987 (4): 964–974. doi:10.2307/1445560. JSTOR 1445560. 
  28. ^ a b c d Fowler, S.L.; Cavanagh, R.D.; Camhi, M.; Burgess, G.H.; Cailliet, G.M.; Fordham, S.V.; Simpfendorfer, C.A. & Musick, J.A. (2005). Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. International Union for Conservation of Nature and Natural Resources. pp. 106–109, 293–295. ISBN 2-8317-0700-5. 
  29. ^ a b Killam, K.A. & Parsons, G.R. (May 1989). "Age and Growth of the Blacktip Shark, Carcharhinus limbatus, near Tampa Bay" (PDF). Florida Fishery Bulletin. 87: 845–857. 
  30. ^ Wintner, S.P. & Cliff, G. (1996). "Age and growth determination of the blacktip shark, Carcharhinus limbatus, from the east coast of South Africa" (PDF). Fishery Bulletin. 94 (1): 135–144. 
  31. ^ Chapman, D.D.; Firchau, B. & Shivji, M.S. (2008). "Parthenogenesis in a large-bodied requiem shark, the blacktip Carcharhinus limbatus". Journal of Fish Biology. 73 (6): 1473–1477. doi:10.1111/j.1095-8649.2008.02018.x. 
  32. ^ ISAF Statistics on Attacking Species of Shark. International Shark Attack File, Florida Museum of Natural History, University of Florida. Retrieved on April 22, 2009.
  33. ^ Musick, J.A.; Fowler, S. (2000). "Carcharhinus limbatus". IUCN Red List of Threatened Species. Version 2007. International Union for Conservation of Nature. Retrieved April 27, 2009. 
source: http://en.wikipedia.org/wiki/Blacktip_shark

Gafftopsail Catfish 2


Gafftopsail Catfish 2 by Inked Animal
Gafftopsail Catfish | Bagre marinus

 This Gyotaku deserves to be on a chinese restaurant’s wall.  Its very asian looking with the extremely falcate fins.  This animal was caught by either Adam or myself on a fishing trip to Matagorda Bay, one of our usual stomping grounds and sources for much of our saltwater material.  It is an interesting print, and misleading categorization, being that it doesn’t have scales.  Many catfish don’t have scales, but smooth skin which comes out in this print in an interesting way. Notice the wrinkles and paper creases.  Also, the long “swoop” from its chin back is the very long barbel that is covered in essentially taste buds.  Its what this animal uses to sense food.  If you like cats, make sure you check out Gafftop Catfish, Hardhead Catfish, and Hardhead Catfish – head.

 

 

 

 

 

 


 

Gafftopsail Catfish info via wikipedia:

Gafftopsail catfish
Bagre marinus (line art).jpg
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Ariidae
Genus: Bagre
Species: B. marinus
Binomial name
Bagre marinus
(Mitchill, 1815)
Synonyms[2]
  • Silurus marinus Mitchill, 1815
  • Felichthys marinus (Mitchill, 1815)
  • Galeichthys blochii Valenciennes, 1840
  • Galeichthys parrae Valenciennes, 1840
  • Galeichthys bahiensis Castelnau, 1855
  • Aelurichthys longispinis Günther, 1864

The gafftopsail catfish (Bagre marinus) is found in the waters of the western central Atlantic Ocean, as well as the Gulf of Mexico and the Caribbean Sea. It has long venomous spines which can cause painful wounds. It feeds on crustaceans and other fish. The male of the species fertilizes the eggs of the female, and broods them in his mouth until they hatch. The gafftopsail feeds throughout the water column. This fish is a common catch in the Southeastern US, although it may be found as far north as New York. In fishing, they are considered strong fighters. They are taken from piers, jetties, reefs, and the surf, as well as bottom fishing or flats fishing. They are caught with lures, cut bait, and shrimp, as well as soft plastics. Some fishermen use traps for catfish, which is regulated by some states.

Distribution

It lives on the Atlantic, Caribbean and Gulf of Mexico coastlines from Cape Cod to Brazil.[1] It is also found in brackish waters, including estuaries, lagoons, brackish seas, and mangroves. It is generally common to abundant in its range.[1]

Characteristics

The gafftopsail catfish is blue-grey to dark brown with a light grey belly. Its appearance is typical for a catfish except for the deeply forked tail and the venomous, serrated spines. It also has a little hump that looks somewhat like a wave. The typical length of a mature gafftopsail catfish is about 17 in (43 cm). The anal fin is a few inches anterior to the tail and is white or pale blue, with 22-28 rays on it and a high, anterior lobe.[3] The pelvic fin is 6–12 in (15–30 cm) anterior to the tail fin. The gafftopsail catfish has maxillary barbels and one pair of barbels on the chin. It resembles the hardhead catfish, but its dorsal spine has a distinctive fleshy extension (like the fore-and-aft topsail of a ship).

The primary food of juveniles is unidentifiable organic matter; the secondary food is fish, with smaller amounts from other trophic groups. Unlike many other catfish, which are primarily bottom feeders, the gafftopsail catfish feeds throughout the water column. It eats mostly crustaceans, including crabs, shrimp, and prawns (95% of the diet), but it will also eat worms, other invertebrates, and bony fishes (about 5% of the diet).[4] In addition to humans, predators of the gafftopsail catfish include the tiger shark and bull shark.

Gafftopsail catfish spawn over inshore mudflats during a relatively short time span (10 days) from May to August;[5] they are mouthbreeders. The eggs are about 1 in (2.5 cm) in diameter. Males keep up to 55 eggs in their mouths until they hatch. Young are about 5 cm (2 inches) long when they hatch, and the male may continue to brood them until they are up to 4 in (10 cm) long. The males do not feed while they are carrying the eggs or young.[6]

Fishing

The gafftopsail catfish is a common catch in the Southeastern United States, although it is also caught as far north as New York. They are taken from piers, jetties, reefs, and the surf, as well as bottom fishing or flats fishing. They are caught with lures such as plugs, spoons, spinners, cut bait, and shrimp, as well as soft plastic lure resembling shrimp, worms, and shad. They are attracted to the sound of struggling fish, like a popping cork creates. Catfish trapping is also used to capture them, but is regulated in some states. Catfish traps include “slat traps,” long wooden traps with an angled entrance, and wire hoop traps. Typical bait for these traps includes rotten cheese and dog food.

Gafftopsail catfish are good eating; the red lateral line should be removed to prevent “muddy taste”; however in Gafftopsail taken from southern Florida mangrove estuaries, this is seemingly unnecessary. The pectoral fins and dorsal fin contain venomous spines; care should be used when handling this fish.

Weight and length

Growth chart

The largest recorded weight for a gafftopsail catfish is 4.5 kg (9.9 lb)[7] and 69 cm (27 in) in length.[8] A more common weight and length of gafftopsails caught is 1–2 lb (450–910 g) and 12–16 in (30–41 cm).

As gafftopsail catfish grow longer, they increase in weight, but the relationship is not linear. The relationship between total length (L, in inches) and total weight (W, in pounds) for nearly all species of fish can be expressed by an equation of the form:

W = c L b {\displaystyle W=cL^{b}\!\,} W=cL^{b}\!\,

Invariably, b is close to 3.0 for all species, and the constant ct varies between species.[9] Data from the Florida Fish and Wildlife Conservation Commission indicate, for the gafftopsail catfish, c = 0.000493 and b = 3.075[10] The relationship described in this section suggests a 12-inch gafftopsail catfish will weigh about one pound, while a 20-inch fish will likely weigh about five pounds.

References

  1. ^ a b c Chao, L.; Vega-Cendejas, M.; Tolan, J.; Jelks, H. & Espinosa-Perez, H. (2015). "Bagre marinus". IUCN Red List of Threatened Species. Version 2017.1. International Union for Conservation of Nature. Retrieved 18 February 2017. 
  2. ^ "Synonyms of Bagre marinus (Mitchill, 1815)". Fishbase.org. Retrieved 29 July 2017. 
  3. ^ Smith, C. Lavett. National Audubon Society Field Guide to Tropical Marine Fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda. Chanticleer Press, 1997, ISBN 0-679-44601-X, pp. 85 & 346
  4. ^ FishBase.org: Food and Feeding Habits Summary - Bagre Marinus see online accessed 11 March 2010
  5. ^ Muncy R.J., Wingo W.M.,Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico): Sea Catfish and Gafftopsail Catfish read online p. 4
  6. ^ Smith, pp. 85 & 346
  7. ^ IGFA 2007 Database of IGFA angling records. IGFA, Ft. Lauderdale, FL, USA http://www.igfa.org/Records/Fish-Records.aspx?Fish=Catfish, gafftopsail&LC=ATR
  8. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Bagre marinus" in FishBase. February 2017 version.
  9. ^ R. O. Anderson and R. M. Neumann, Length, Weight, and Associated Structural Indices, in Fisheries Techniques, second edition, B.E. Murphy and D.W. Willis, eds., American Fisheries Society, 1996.
  10. ^ average of data for male and female gafftopsail catfish at Florida Fish and Wildlife Conservation Commission Report 2008 accessed 7 March 2010
source: http://en.wikipedia.org/wiki/Gafftopsail_catfish

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