Sunday, 25 March 2012

Pacific halibut


Name
The Pacific halibut (Hippoglossus stenolepis) between 5 and 10 pounds (2.3-4.5kg) are known locally as “chickens” those of 10-60 pounds (4.5-27.2kg) are called "mediums" and over 60 pounds as "large". The halibut in the weight group over 80 pounds (36.3kg) are sometimes called "whales". Weights are for head-off.
Location
Cobb Seamount, Arctic Ocean, Beaufort Sea, California Current, Chukchi Sea, East Bering Sea, Gulf of Alaska, Kuroshio Current, Pacific Ocean, Sea of Japan, Sea of Okhotsk, West Bering Sea. The Pacific halibut, Hippoglossus stenolepis, is found on the continental shelf of the North Pacific Ocean and Bering Sea. Fishing for the Pacific halibut is mostly concentrated in the Gulf of Alaska and the Bering Sea, off the West coast of Canada. Small halibut catches are reported in coastal Washington, Oregon, and California. Pacific halibut is broken up to ten regularity management areas.
Habitat
Halibut is a demersal species that live on or near the ocean floor generally found on the continental shelf in north temperate waters. Its distribution, both in the Pacific and the Atlantic, tends to be within bottom water temperatures ranging from 3-8°C. Most halibut in the Pacific are found in waters from 10 fathoms.

Appearance
Pacific halibut have diamond-shaped bodies. They are more elongated than most flatfishes, the width being about 1/3 of the length. There is a high arch in the lateral line over the pectoral fin, and it has a lunate, or crescent shaped tail, which is different from other flat fishes. Small scales are embedded in the skin. Halibut have both eyes on their dark or upper side of the body. The color on the dark side varies, but tends to assume the coloration of the ocean bottom. The underside is lighter, appearing more like the sky from below. This color adaptation allows halibut to avoid detection by both prey and predator. 
Diet
Being strong swimmers, halibut are able to eat a large variety of fishes including cod, turbot, Alaska pollock or walleye pollock, and some invertebrates such as octopus, Tanner crab, rhinoceros crabpygmy rock crab ,flathead sole and shrimp. Sometimes halibut leave the ocean bottom to feed on pelagic fish such as salmon, Pacific sand lance, Atka mackerel, Capelin, Pacific herring and Pacific ocean perch.

Method of Catching
Halibut taken by anglers are generally 15 to 20 pounds (6.8 to 9.1 kg) in weight; however, fish over 150 pounds (68 kg) are regularly caught. Anglers use stout saltwater gear to harvest halibut. Most anglers prefer to fish with bait, especially herring but also squid, octopus, cod pieces, or other small bottom fish. To get the bait down to the halibut, it is usually fished on a wire spreader or a sliding-sinker rig with sinker size 4 ounces (113 g) to 4 pounds (1.81 kg), depending on such factors as depth and current. Sport fishing for halibut in Alaska is a very popular activity; it is a strong fighter and one of the world’s largest bony fish with an impressive yield and firm, white flesh. 

Edible
Dietary Information: Pacific Halibut has very lean meat, making it an excellent menu choice for health-conscious consumers. Serving Size per 3.5 oz raw edible portion, Calories 91, Total Fat 1.33g, Saturated Fat 0.292g, Protein 18.56g, Sodium 68mg, Selenium 45.6mcg, Cholesterol 49mg, Omega-3 0.43g. Halibut does host a parasitic worm found generally around the gut cavity, current research suggests its not fatal to humans and proper preparation either freezing Halibut for 48 hours or thoroughly cooking the flesh will eliminate all the parasites , although normal refrigerator freezers can not reach the required negative temperature to kill theses parasites temperatures on the stove when cooking are optimum enough to kill the parasites ,when cooking, internal temperatures need to reach around 62 degree's for 15 seconds to eliminate all the parasites in the flesh 

Spawning Season/Grounds
spawning takes place off the edge of the continental shelf in deep waters about 200 to 300 fathoms (1,200 to 1,800 ft; 370 to 550 m) Young are found near shore, moving out to deeper waters as they grow older. Older individuals typically move from deeper water along the edge of the continental shelf where they spend the winter, to shallow coastal water (27-274 m) for the summer. 

Predators
Pacific sleeper shark, Pacific cod

Sunday, 18 March 2012

Rainbow Runner/rainbow yellowtail/Spanish jack/Hawaiian salmon


Name
The rainbow runner (Elagatis bipinnulata), also known as the rainbow yellowtailSpanish jack and Hawaiian salmon.

Location
The rainbow runner inhabits tropical and some subtropical waters worldwide. In the Western Atlantic, the species occurs from Massachusetts and Bermuda to north eastern Brazil, including the northern and southern Gulf of Mexico, the Bahamas and the Greater and Lesser Antilles, extending east to at least the Azores. The species is widespread throughout the Pacific Ocean, but appears to be slightly less abundant in parts of the Indian Ocean, and rare or absent in the Persian Gulf. The species is an occasional visitor to the Mediterranean Sea, generally as a Lessepsian also called Erythrean invasion through the Suez Canal, but has not taken up permanent residence like other species. The species also inhabits the nearby Canary Islands, possibly entering the Mediterranean from the east also.

Habitat
The species is primarily pelagic, inhabiting the upper 164 m of the water column, sometimes close to land over rock and coral reef systems, as well as far offshore. The species occasionally comes quite close to shore, known to inhabits lagoons for short periods, and juveniles have even been reported in a Taiwanese estuary system. Rainbow runner, like other carangids such as Yellowtail kingfish are easily attracted to special Fish Attracting Devices (FAD's), floating buoy type structures. The species has been shown to occupy a water zone outside of the FAD up to 12 m deep and 10 m wide, treating it as if it were a stationary object.

Appearance
The colour of the fish is possibly the easiest way to identify the rainbow runner. The upper body is a dark olive blue to green and fading to white underneath. There are two narrow light blue to bluish white stripes running longitudinally along the sides, with a broader olive to yellow stripe between them. The maximum length of the species is somewhat contentious, with most sources giving a known maximum length of between 107 cm (42 in) and 120 cm (47 in) cm, while one source asserts the species reaches 180 cm (71 in) in length. The maximum known weight is confidently known to be 46.2 kg, The rainbow runner has a body that is sub-cylindrical, elongated to almost fusiform body, with a long pointed head and snout and a tapering rear end before the caudal fin emerges. The eye is relatively small and the teeth are arranged on jaws in villiform bands, with minute teeth also present on the roof of the mouth and tongue. The fish has two dorsal fins, although the rear rays of the long second fin have separated into a finlet. The first dorsal consists of 6 spines, the second of a single spine and 25 to 30 soft rays, with the last two as a separate finlet. Approximately 4% of rainbow runner have only five spines in the first dorsal fin, and are apparently born without them. The anal fin consists of one spine detached from the fin anteriorally, while the main fin has a single spine and 18 to 22 soft rays, with the last two detached to form a finlet like the dorsal fin. The dorsal and anal fins are quite low, and the dorsal fin is much longer than the anal. The pectoral fin is small for a carangid, about the length of the pelvic fin and is non-falcate with 20 rays. The pelvic fin consists of one spine and five branched soft rays. The caudal fin is deeply forked and consisting of 17 caudal rays, 9 dorsally and 8 ventrally. The lateral line has a slight anterior arch and there are no scutes present on the line, but possesses about 100 scales. The scales covering the body and parts of the gill cover, cheek, pectoral fins, pelvic fins. The species has 24 vertebrae.
Diet
Rainbow runner are fast swimming carnivores that take a wide range of prey including a wide variety of small fishes, inkfish and pelagic or planktonic crustaceans including, shrimps and crabs. It has been demonstrated that the species shows selectivity of its prey, with fish in the Pacific Ocean taking higher amounts of  Mackerel scad, a small fish, than any other prey available. It was also found in the same study that rainbow runner may increase the swimming and prey searching abilities rapidly with their growth, becoming more efficient at finding their preferred prey items. Rainbow runner are also one of a number of pelagic fishes that prey on open-ocean species of sea-skaters/striders, a type of insect which rest on the surface of the ocean. 
Method of Catching
Taken while trolling for other species such as tuna and mackerel, but are often targeted inshore by anglers on the west coast of the Americas using surface 'popper' style lures. The fish are caught on a wide variety of lures and baits, with deep diving lures, surface lures and even saltwater flies used to good measure. The species takes a wide variety of baits including live and cut fish, squid, octopus. 

Edible
Their flesh is said to be of fair to excellent standard, depending on personal preferences. At least one case of ciguatera poisoning has been reported from this species on the Virgin Islands. 
Spawning ground/Season
The size at sexual maturity is only confidently known for the female of the species, being around 600 mm in fork length, although the male has been estimated to reach maturity at between 600 and 650 mm. In the Atlantic, the species is known to spawn from spring through to early autumn, although fish living in waters greater than 27 degrees Celsius spawn year round. However, even when year-round spawning occurs, there are seasonal peaks, with fish in the Western Pacific Ocean showing these peaks in May and in December – January. The fish is oviparous, producing pelagic eggs and larvae, with the diagnostic features of the larvae include a supraoccupital crest and distinctive patterns of pigment and melanophores. The growth of the fish has also been studied, with the size of fish at 1, 2, 3, 4 and 5 years ages are estimated to be 30, 46, 59, 69 and 77 cm in length respectively.

Predators
The species themselves are also commonly used as bait, either as live bait or dead bait rigged to be trolled behind game boats for larger species such as billfish and tuna.


*feel free to leave a comment below.

Saturday, 17 March 2012

King Mackerel


Name
The king mackerel (Scomberomorus cavalla

Location
The king mackerel is a subtropical species of the Atlantic Coast of the Americas. Common in the coastal zone from North Carolina to Brazil, it occurs as far south as Rio de Janeiro, and occasionally as far north as the Gulf of Maine, a preference for water temperatures in the range of 68 to 85 °F (20 to 29 °C) may limit distribution.

Habitat
King mackerel commonly occur in depths of 40 to 150 feet (12–45 m), where the principal fisheries occur. Larger kings (heavier than 20 lb or 9 kg) often occur inshore, in the mouths of inlets and harbors, and occasionally even at the 600-foot (180-m) depths at the edge of the Gulf Stream. 

Appearance
The king mackerel is a medium-sized fish, typically encountered from five to 30 pounds, but is known to exceed 90 pounds. The entire body is covered with very small, hardly visible, loosely attached scales. The first (spiny) dorsal fin is entirely colorless and is normally folded back into a body groove, as are the pelvic fins. The lateral line starts high on the shoulder, dips abruptly at mid-body and then continues as a wavy horizontal line to the tail. Coloration is olive on the back, fading to silver with a rosy iridescence on the sides, fading to white on the belly. Fish under 10 pounds (5 kg) show yellowish-brown spots on the flanks. Its cutting-edged teeth are large, uniform, closely spaced and flattened from side to side. These teeth look very sharp and razor like in appearance.

Diet
King mackerel are voracious, opportunistic carnivores. Their prey depends on their size. Depending on area and season, they favor menhaden and other sardine-like fish, jacks, Cutlassfish, weakfish, grunts, striped anchovies, cigar minnows, threadfin, northern mackerel and blue runners. 

Method of catching
Are taken mostly by trolling, using various live and dead baitfish, spoons, jigs and other artificial lures. Commercial gear consists of run-around gill nets. They are also taken commercially by trolling with large planers, heavy tackle and lures similar to those used by sport fishers. Typically when using live bait, two hooks are tied to a strong metal leader. The first may be a treble or single and is hooked through the live bait's nose and/or mouth. The second hook (treble hook) is placed through the top of the fish's back or allowed to swing free. This must be done because king mackerel commonly bite the tail section of a bait fish. Typical tackle includes a conventional or spinning reel capable of holding 400 yards (370 m) of 20 lb (9 kg) test mono filament and a 7 foot (2.1 m), 20 pound (9 kg) class rod.

Edible
King mackerel are primarily marketed fresh. They may be sold as fillets, steaks, or in the round (whole). Their raw flesh is grayish, due to its high fat content. They are best prepared by broiling, frying, baking or, especially for large "smoker" king, by smoking. king mackerel is one of four fishes, along with swordfish, shark, and tilefish, that children and pregnant women should avoid due to high levels of methylmercury found in these fish and the consequent risk of mercury poisoning.

Spawning ground/season
An Atlantic group is abundant off North Carolina in spring and fall. This group migrates to southeast Florida, where it spawns from May through August, and slowly returns through summer. Apparently, this group winters in deep water off the Carolinas, as tagging studies have shown they are never found off Florida in winter.At least two migratory groups of king mackerel have been found to exist off the American coast. A Gulf of Mexico group ranges from the Texas coast in summer to the middle-east coast of Florida from November through March. Spawning occurs throughout the summer off the northern Gulf Coast. Eggs and sperm are shed into the sea and their union is by chance. Depending on size, a female may shed from 50,000 to several million eggs over the spawning season. Fertilized eggs hatch in about 24 hours. The newly hatched larva is about 0.1 inches (2.5 mm) long with a large yolk sack. Little is known about king mackerel in their first year of life. Yearling fish typically attain an average weight of 3 to 4 pounds (1.4–1.8 kg) and a fork length of 25 inches (60 cm). At age seven, females average 21 lb (9.5 kg), males 11 lb (5 kg). King mackerel may attain 90 lb (40 kg), but any over 15 pounds (7 kg) is almost certainly a female.


*feel free to leave a comment below.

Monday, 12 March 2012

mahi-mahi/common dolphinfish/lampuga/lampuka/rakingo/calitos/maverikos/dorado/pompano dolphinfish


Name
The mahi-mahi or common dolphinfish (Coryphaena hippurus). The name mahi-mahi means very strong in Hawaiian. In other languages the fish is known as lampuga, lampuka, lampuki, rakingo, calitos, or maverikos. Also known widely as dorado. 

Location 
Found in off-shore temperate, tropical and subtropical waters worldwide. Mahi-mahi can be found in the Caribbean Sea, on the west coast of North and South America, the Pacific coast of Costa Rica, the Gulf of Mexico, the Atlantic coast of Florida, Southeast Asia, Hawaii.

Habitat 
 Fishing charters most often look for floating debris and frigate birds near the edge of the reef in about 120 feet (37 m) of water. Mahi-mahi is a surface-dwelling ray-finned fish often swimming near debris such as floating wood, palm trees and fronds, or Sargasso weed lines and around fish buoysSargasso is floating seaweed that sometimes holds a complete ecosystem from microscopic creatures to seahorses and baitfish. Frigate birds dive for food accompanying the debris or Sargasso, hence the phrase "Tree of life" . Experienced fishing guides can tell what species are likely around the debris by the birds' behavior.

Appearance
Mahi-mahi have compressed bodies and long dorsal fins extending nearly the entire length of their bodies. Their caudal fins and anal fins are sharply concave. They are distinguished by dazzling colors, golden on the sides, and bright blues and greens on the sides and back. Mature males have prominent foreheads protruding well above the body proper. Females have a rounded head. Females are also usually smaller than males. Out of the water, the fish often change color among several hues (giving rise to their Spanish name, dorado maverikos, ("golden maverick"), finally fading to a muted yellow-grey upon death. Dolphinfish have been shown to be sexually dimorphic at  around 40-50cm fork length. In comparison with available age/growth charts, this equates to male and female dolphinfish being readily discernable from one another by the time they are 4-5 months old by examining the slope of their forehead. The males have blunt square head shape while the females have a more rounded sloped head shape. In general, dolphinfish in the Western Atlantic show a tendency to reach maturity in 5-7 months and can spawn continuously. it is one of only two members of the Coryphaenidae family, the other being the pompano dolphinfish.


Diet
Mahi-mahi are carnivorous, feeding on flyingfish, crabs, squid, mackerel, herrings, sardines, shad, hilsa, menhaden, anchovies and sprats also other small fish, including halfbeaks, smelt such as capelin, and the goldband fusiliers. They have also been known to eat zooplankton and crustaceans. Sargasso found in the stomachs of several dolphinfish imply the importance of continued investigations into the relationship between the fish and the mobile habitat in which it is closely linked to.



Method of catching 
Thirty- to fifty-pound gear is more than adequate when trolling for mahi-mahi. Fly-casters may especially seek frigatebirds to find big mahi-mahis, and then use a bait-and-switch technique. Ballyhoo or a net full of live sardines tossed into the water can excite the mahi-mahis into a feeding frenzy. Hookless teaser lures can have the same effect. After tossing the teasers or live chum, fishermen throw the fly to the feeding mahi-mahi.
Edible 
Sport fishermen seek them due to their beauty, size, food quality, and healthy populations. 


Spawning ground/season 
Mahi-mahi are among the fastest-growing fish. They spawn in warm ocean currents throughout much of the year, and their young are commonly found in seaweed. Males and females are sexually mature in their first year, usually by 4-5 months old. Spawning can occur at body lengths of 20 cm. Females may spawn two to three times per year, and produce between 80,000 and 1,000,000 eggs per event. In waters above 34 °C, mahi-mahi larvae are found year-round, with greater numbers detected in spring and fall. In one study, seventy percent of the youngest larvae collected in the northern Gulf of Mexico were found at a depth greater than 180 meters. Spawning occurs normally in captivity, with 100,000 eggs per event.


_________________________________________________________________________________



Name
The pompano dolphinfish (Coryphaena equiselis) 


Location 
Pompano have been shown to be common in the waters around Bermuda. Fishermen in the Florida Straits have documented pompano dolphin occurring in the same school with common dolphinfish and even in mixed schools of common dolphin and blackfin tuna.  

Habitat 
Closely related to above mentioned habitats since the swim bladder is related in the same way.

Appearance
Pompano dolphinfish have compressed heads and long dorsal fins extending the entire length of their bodies. Rays in the dorsal fin are 48 to 55 rays, Greatest body depth vertically occurs at mid-body in front of anal fin, Pectoral fin is short with less than half of head length, All rays are the same length at the anal fin with no longer lobe present the edge of the fin is straight, Tongue tooth patch is large and rectangular in shape. Their backs are a brilliant blue-green, and their sides are a silvery-golden color. Mature males develop a protruding forehead, but not to the same extent as male mahi-mahi. When they are removed from the water, the fish fade to a muted green-grey upon death.

Diet
Pompano dolphinfish are carnivorous, feeding on small fish and squid. being a close relative to the dolphinfish, its "superficial to say the same as the above mentioned paragraph"

Method of catching 
Same as the above mentioned paragraph, "have not encountered a fishermen targeting this specific species of fish only" 

Edible 
Pompano dolphinfish are popular as a game fish in the waters off South America, and are sometimes eaten as a substitute for swordfish because of their firm texture and sweet flavor.

Spawning ground/season 
Pompano dolphinfish have a lifespan of three to four years. They are often mistaken for juvenile mahi-mahi; they are somewhat smaller than their mahi-mahi cousins, never exceeding 127 cm in length


*feel free to leave a comment below. 

Saturday, 10 March 2012

Albacore Tuna/albacore fish/albacore tuna/albicore/longfin/albies/pigfish/tombo ahi/binnaga/Pacific albacore/German bonito/long-fin tuna/longfin tunny/Yellowfin tuna/ahi/Allison tuna/Big eye Tuna/big eyed tuna/bigeye tunny/


Albacore Tuna
The albacore, Thunnus alalunga, This species is also called albacore fish, albacore tuna, albicore, longfin,albies, pigfish, tombo ahi, binnaga, Pacific albacore, German bonito , long-fin tuna, longfin tunny, or even just tuna. It is the only tuna species which may be marketed as "white meat tuna" . It is found in the open waters of all tropical and temperate oceans, and the Mediterranean Sea. Lengths range up to 140 cm (4.5 feet) and weights up to 45 kg (99 lb).
Method of catching
Methods of fishing include pole and line, long-line fishing, trolling , and some purse seining. It is also sought after by sport fishers. trolling with feathered jigs, spoons and lures; live and whole bait fishing with mullet, sardines, squid, herring, anchovies, sardines and other small fish.

Appearance 
The pectoral fins of the albacore are very long, as much as 50% of the total length. The dorsal spines are 8 to 10 in number, and well forward of the rays of the dorsal fin. The anterior spines are much longer, giving a concave outline to the spiny part of the dorsal fin.The most distinguishing feature of this member of the tuna and mackerel family is its very long pectoral fins that reach to a point beyond the anal fin. The pectoral fins of other adult tunas may also be moderately long, but never extend all the way to the anal fin.

 Migrations:
Albacore tuna is a highly migratory finfish species that roams that roams thee waters of the world. It is found in the open waters of all tropical and temperate oceans, and the Mediterranean Sea.North Pacific albacore, particularly juveniles (2-4 years old), typically begin their expansive migration in the spring and early summer in waters off Japan. They move into inshore waters off the U.S. Pacific coast by late summer, then spend late fall and winter in the western Pacific Ocean. The timing and distance of albacore tunas' migrations in a given year depend on oceanic conditions. Less is known about the movements of albacore in the South Pacific Ocean – juveniles move southward from the tropics when they are about a foot long, and then eastward to about 130°W. When the fish reach sexual maturity, they return to waters where they spawn.

Habitat
Temperature is a major factor in determining where Pacific albacore live. Juveniles are often found near oceanic fronts or temperate discontinuities; adults are found in depths of at least 1,250 feet. They will also explore deeper waters in search of prey.In Australia albacore tuna are present in east and south Australian waters and from east of Torres Strait to the north west shelf. The distribution of albacore is related to oxygen concentration and water temperature. Whilst albacore feed at the surface, they primarily live at the thermocline, which is the boundary separating warmer surface waters and deeper cooler waters. Mature albacore travel from temperate waters to the tropics but return to temperate waters after spawning. Albacore are generally caught in waters off New South Wales from September to December and in April and May.Geographic range , In tropical, subtropical, and temperate zones of the Pacific, Atlantic, and Indian Oceans.
Spawning grounds
In tropical and subtropical waters in the Pacific centered around 20° North to 20° South latitude, with less activity towards the equator.

Spawning season
 North Pacific albacore spawn between March and July in the western and central Pacific.

Reproduction
 Females have 0.8 to 2.6 million eggs per spawning (100,000 eggs per 2.2 pounds of body weight). They broadcast the eggs in water near the surface, where they are externally fertilized. Reaches reproductive maturity At roughly 5 to 6 years old and 33.5 inches in length, Growth rate: Growth progresses more slowly with age. Eggs develop rapidly, hatching within 24 to 48 hours. Juveniles grow at an estimated 1¼ inches per month.

Diet
 Albacore are top carnivores. They opportunistically prey on schooling stocks, such as sardine, anchovy, and squid. They eat an enormous amount of food to fuel their high metabolism, sometimes consuming as much as 25% of their own weight every day. Anglers often use trolling methods with artificial lures and live or dead baits to catch albacore.

Predators
 Larger species of bill-fish, tuna, and sharks.

Trophic Level-4.31
Level 4 Trophic Level : Carnivores which eat other carnivores are called tertiary consumers. -Near Threatened.

_________________________________________________________________________________



Name
The yellowfin tuna (Thunnus albacaresmarketed as ahi, from its Hawaiian name ʻahi although the name ʻahi in Hawaiian also refers to the closely related bigeye tuna. The species name, albacares ("white meat") can lead to confusion. The tuna known as albacore in English, is a different species of tuna: Thunnus alalunga. However, yellowfin tuna is officially designated albacore in French, and is referred to as albacora by Portuguese fishermen. Also known as Allison tuna.



Method of catching

Using correct tuna bait and chumming, time of day/night, yellowfin tuna hooks and rigs, their preferred water temperature, yellow fin tuna lures, correct ocean depth, precise trolling speed. You can catch yellowfin tuna by a combination of bait techniques, either trolling live or dead baits behind the boat from between 4 – 12 knots. They love to feed on pilchards, small skipjack tuna, mackerel, and especially squid. Smaller skirted trolling lures in the size range 20cm , 25cm to 35cm marlin lures are kept just behind the whitewash of the boat, because the yellowfin will be attracted by the bubbles. Cubing in consistent 10m (22ft) intervals is a productive way to entice the fish to your lure.


Appearance
The second dorsal fin and the anal fin, as well as the finlets between those fins and the tail, are bright yellow, giving this fish its common name. The second dorsal and anal fins can be very long in mature specimens, reaching almost as far back as the tail and giving the appearance of sickles or scimitars The main body is very dark metallic blue, changing to silver on the belly, which has about 20 vertical lines.

Habitat
Yellowfin tuna are epipelagic fish that inhabit the mixed surface layer of the ocean above the thermocline. Sonic tracking has found that although yellowfin tuna, mostly range in the top 100 meters (330 ft) of the water column and penetrate the thermocline relatively infrequently, they are capable of diving to considerable depths. An individual tagged in the Indian Ocean with an archival tag spent 85% of its time in depths shallower than 75 meters (246 ft) but was recorded as having made three dives to 578 m, 982 m and 1,160 meters (3,810 ft). Yellowfin tuna travel along vertical thermal gradients where warm water pushes against the edge of colder water.
Spawning season
Spawning throughout the tropical and equatorial waters of the major oceans. At higher latitudes, spawning is seasonal, with peaks in summer, may continue throughout the year at lower latitudes. Spawning records show Coast of Mexico and Central America, Revillagigedo Island spawning through out the year ,Eastern Atlantic from Feb-Sept, Gulf of Mexico from May-Jun, Hawaiian Islands May-Sept, Mauritanie coast Jun-Jul, Northeast coast of Australia Oct-Mar, Northwest Pacific Apr-Jul, Northwestern Coral Sea Oct-Jan, and West coast of Senegal from May-Sept.

Reproduction
 It is likely that yellow-fin reach maturity at three years of age. Female yellow-fin are prolific egg layers capable of spawning every day, or second day, for several months. Their eggs are epipelagic which means they float on the surface.
Diet
Yellowfin tuna prey include other fish, pelagic crustaceans, and squid. Like all tunas their body shape is evolved for speed, enabling them to pursue and capture fast-moving bait fish such as flying fish,saury and mackerel. Schooling species such as myctophids or lantern fish and similar pelagic drift fish, anchovies and sardines are frequently taken. Large yellow-fin prey on smaller members of the tuna family such as frigate mackerel and skip jack tuna.

Predators
Yellowfin are preyed upon when young by other pelagic hunters, including larger tuna, seabirds and predatory fishes such as yahoo, shark and bill-fish. As they increase in size and speed, yellowfin become able to escape most of their predators. Adults are threatened only by the largest and fastest hunters, such as toothed whales, particularly the false killer whale, pelagic sharks such as the Mako, great white, cookie cutter shark and larger blue marlin and black marlin.

Trophic Level -4.34
Level 4: Carnivores which eat other carnivores are called tertiary consumers. Near Threatened 


_______________________________________________________________________




Name
The bigeye tuna, Thunnus obesus, is an important food fish and prized recreational game fish. It is a true tuna of the genus Thunnus, belonging to the wider mackerel family Scombridae. 

Appearance 
Bigeye tuna vary up to 250 centimetres (98 in) in length. Its maximum weight probably exceeds 400 pounds (180 kg), with the all-tackle angling record standing at 392 pounds (178 kg). They are large, deep-bodied, streamlined fish with large heads and eyes. The pectoral fins are very long, reaching back as far as the second dorsal fin. They display 13 or 14 dorsal spines. 

Location
Admiralty Is, Amer Samoa, Andaman Is, Angola AGO, Anguilla AIA, Antigua Barb, Argentina, Aruba, Ascension I. Australia, Azores Is, Bahamas, Bangladesh, Barbados, Benin, Bermuda, Br Ind Oc Tr, Br Virgin Is, Brazil, Brunei Darsm, Cameroon, Canada, Canary Is, Cape Verde, Cayman Is, Chagos Is, China Main, Christmas I. Cocos Is, Colombia, Comoros, Congo Dem Rep, Congo Rep, Cook Is, Cote d'Ivoire, Cuba, Curaçao I. Djibouti, Dominica, Dominican Rp, East Timor, Easter I. Ecuador, Eq Guinea, Fiji, Fr Guiana, Fr Polynesia, Gabon, Galapagos Is, Gambia, Ghana, Grenada, Guadeloupe, Guam, Guinea, GuineaBissau, Guyana, Haiti, Hawaii, India, Indonesia, Jamaica, Japan, Johnston I. Kenya, Kermadec Is, Kiribati, Korea Rep, Liberia, Madagascar, Madeira Is, Malaysia,Maldives, Marquesas Is, Marshall Is, Martinique, Mauritania, Mauritius, Mexico, Micronesia, Midway Is, Montserrat, Morocco, Mozambique, Myanmar, N Marianas, Namibia, Nauru, NethAntilles, New Caledonia, New Zealand, Nicaragua, Nigeria, Niue, Norfolk I. Ogasawara Is, Oman, Pac Is Tr Tr, Pakistan, Palau, Papua N Guin, Peru, Philippines, Pitcairn, Portugal, Puerto Rico, Reunion, Ryukyu Is, Saint Lucia, Samoa, Sao Tome Prn, Senegal, Seychelles, Sierra Leone, Solomon Is, Somalia, South Africa, Spain, Sri Lanka, St Helena, St Kitts Nev, St Vincent, Suriname, Tahiti, Taiwan, Tanzania, Thailand, Togo, Tokelau, Tonga, Trinidad Tob, Tuamotu Is, Turkey, Turks Caicos, Tuvalu, Uruguay, US Minor Is, US Virgin Is, USA, Vanuatu,Venezuela, Viet Nam, 
Wake I. Wallis Fut I, West Sahara.

Migrations
Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not the Mediterranean Sea. Satellite tagging showed that bigeye tuna often spend prolonged periods diving deep below the surface during the daytime, sometimes reaching 500 metres (1,600 ft). Bigeye have been tracked entering water as cold as 5 °C (41 °F). These movements are thought to be in response to vertical migrations of prey organisms in the deep scattering layer.

Habitat 
The bigeye forages in cold and oxygen-poor subsurface waters. Their blood extracts oxygen efficiently even in oxygen-poor conditions. Their vision functions well in low light conditions. The heart has an unusual ability to function effectively while foraging in cold subsurface water. Nonetheless, they must periodically return to warmer surface waters to warm up.

Spawning grounds/Season
Spawning takes place in June and July in the northwestern tropical Atlantic, and in January and February in the Gulf of Guinea, which is the only known Atlantic nursery area. Occur in areas where water temperatures range from 13°-29°C, but the optimum is between 17° and 22°C. Variation in occurrence is closely related to seasonal and climatic changes in surface temperature and thermocline. Juveniles and small adults school at the surface in mono-species groups or mixed with other tunas, may be associated with floating objects. Adults stay in deeper waters. Eggs and larvae are pelagic

Reproduction 
Dioecism fish where females and males are separate in gender ,external Fertilization, nonguarders
,open water/substratum egg scatterers , the bigeye tuna are multiple spawners that may spawn every 1 or 2 days over several months . They spawn over periods of the full moon and Spawn throughout the year in tropical waters. has a lifespan of up to 12 years, with sexual maturity at the age of four.

Diet 
Feed items include both epipelagic and mesopelagic species, with deep diving behaviour during the day thought to be related to the seeking of prey. diet consists of the following, skipjack tuna, Porcupinefish, pufferfish, pelagic shrimp, lanternfish, Lancetfish, Lovely Hatchetfish or Atlantic Silver Hatchetfish, Daggertooth, cutlassfish, Australian anchovy, Pomfret, Snipe eels, snake mackerels, hooked squid, octopi, hammerjaw, Barracudinas, Flying fish, ribbonfish, Boarfish, True dories, snaketooth fish, Driftfish. 

Predators 
Cookiecutter shark, killer whale, billfish, Atlantic blue marlin, sperm whales, beaked whales, dolphins. 

Edible
Meat is highly prized and processed into sashimi in Japan. Marketed mainly canned or frozen, but also sold fresh, Parasites are common in this fish and contains mercury, Pregnant woman are advised to not eat large quantities 

Trophic Level-4.49
Level 4: Carnivores which eat other carnivores are called tertiary consumers. Vulnerable