Tuesday, 16 February 2016

Cobia


Name
The cobia (Rachycentron canadum
The only representative of the genus Rachycentron and the family Rachycentridae. Other common names include black kingfish, black salmon, ling, lemonfish, crabeater, prodigal son, black bonito, and aruan tasek.

Appearance
Attaining a maximum length of 2 m (78 in) and maximum weight of 78 kg (172 lb), the cobia has an elongated fusiform (spindle-shaped) body and a broad, flattened head. The eyes are small and the lower jaw projects slightly past the upper. Fibrous villiform teeth line the jaws, the tongue, and the roof of the mouth. The body of the fish is smooth with small scales. It is dark brown in color, grading to white on the belly with two darker brown horizontal bands on the flanks. The stripes are more prominent during spawning, when they darken and the background color lightens. The large pectoral fins are normally carried horizontally. The first dorsal fin has six to 9 independent, short, stout, sharp spines. The family name Rachycentridae, from the Greek words rhachis ("spine") and kentron ("sting"), was inspired by these dorsal spines. The mature cobia has a forked, slightly lunated tail, which is usually dark brown. The fish lacks a swim bladder. The juvenile cobia is patterned with conspicuous bands of black and white and has a rounded tail. Dorsal spines (total): 7 - 9; Dorsal soft rays (total): 26-33; Anal spines: 2-3; Anal soft rays: 22 - 28. Head broad and depressed. First dorsal fin with short but strong isolated spines, not connected by a membrane. Caudal fin lunate in adults, upper lobe longer than lower. Back and sides dark brown, with 2 sharply defined narrow silvery bands.

Location 
Agulhas Current, Andaman Sea, Arabian Sea, Atlantic Ocean, Atulayan Bay, Bay of Bengal, Benguela Current, Canary Current, Caribbean Sea, CelestĂșn Biosphere Reserve, Chesapeake Bay, Coral Sea and GBR, Discovery Bay, East Brazil Shelf, East China Sea, Great Barrier Reef, Guinea Current, Gulf of Aden, Gulf of Aqaba, Gulf of Mexico, Gulf of Oman, Gulf of Thailand, Indian Ocean, Indonesian Sea, Kuroshio Current, Leyte Gulf, Lingayen Gulf, Mediterranean Sea, North Australian Shelf, North Brazil Shelf, Northeast U.S. Continental Shelf, Northwest Australian Shelf, Ormoc Bay, Pacific Central-American Coastal, Pacific Ocean, Patagonian Shelf, Peng-hu Island, Persian Gulf, Red Sea, Samar Sea, San Miguel Bay, San Pedro Bay, Sea of Japan, Somali Coastal Current, Sorsogon Bay, South Brazil Shelf, South China Sea, Southeast U.S. Continental Shelf, Southwest Australian Shelf, Sulu-Celebes Sea, Tayabas Bay, Tung-hsiao, West Central Australian Shelf, Yellow Sea, Chiku River, Chilika Lake,


Habitat
It is found in warm-temperate to tropical waters of the West and East Atlantic Ocean, throughout the Caribbean, and in the Indo-Pacific off India, Australia and Japan. It is eurythermal, tolerating a wide range of temperatures, from 1.6 to 32.2 °C. It is also euryhaline, living atsalinities of 5 to 44.5 ppt. The cobia makes seasonal migrations. It winters in the Gulf of Mexico, then moves north as far as Massachusetts for the summer, passing Florida around March. 

Spawning ground/Season
Breeding activity takes place diurnally from April to September in large offshore congregations, where the female is capable of spawning up to 30 times during the season.

Reproduction 
The cobia is a pelagic spawner, releasing many tiny (1.2 mm), buoyant eggs into the water, where they become part of the plankton. The eggs float freely with the currents until hatching. The larvae are also planktonic, being more or less helpless during their first week until the eyes and mouths develop. The male matures at two years and the female at three years. Both sexes lead moderately long lives of 15 years or more.

Diet 
The cobia feeds primarily on crabs, squid, and fish. It will follow larger animals such as sharks, turtles, and manta rays to scavenge. It is a very curious fish, showing little fear of boats. Lady Crabs, swimming Crabs, Flounders, Squid, smooth Trunkfish, Rabbit fish spinefoot fish(venomous spines) shrimp, flathead lobsters, Round scad, filefish, Croaker fish , mantis shrimp, tuna, Atlantic Menhaden, porcupine pufferfish, seahorses mussels, striped cusk eel ,Atlantic thread herring. oyster toadfish , bluefish ,cownose ray, pipefish  
Freshwater Diet
Catfish eels , tilapia , due to the impressive nature of the cobia freshwater agricultural is possible by feeding the cobia a protein, hoaxing the thermostat within the fish to suitable conditions to allow its thrivability in freshwater

Edible
The cobia is frequently parasitized by nematodes(round worms), trematodes(Flukes), cestodes(Tapeworm). copepods(Crustaceans) and acanthocephalans(Thorny/Spiny headed worms). The cobia is sold commercially and commands a relatively high price for its firm texture and excellent flavor. However, no designated wild fishery exists because it is a solitary species. It has been farmed in aquaculture. The flesh is usually sold fresh. It is typically served in the form of grilled or poached fillets. Its rapid growth rate and the high quality of the flesh could make it one of the most important marine fish for future aquaculture production

Predators 
Predators of the cobia are not well documented, but the mahi-mahi (Coryphaena hippurus) is known to feed on juveniles and theshortfin mako shark (Isurus oxyrinchus) eats the adult.