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Codfish family Gadidae, Cod, Haddock, Pollock, Hake, habitats, characteristics, fishing methods.
The various cod and hake are all members of the Gadidae family of codfish, that include about 25 species in 12 genera. Cod have been important in both commercial fishing and sportfishing, although their significance in both areas has diminished markedly. Species of the Northern Seas are highly valued as food. Some cod are sold fresh, but most of the catch is now processed as frozen fillets. In the early days, cod were preserved mainly by salting. Oil from the cod’s liver was the main source of vitamin D. The flesh of the Cod is firm, white, and of good flavor, best when fresh, but only a very small proportion is consumed in this form. It is generally salted, and appears in the market under the name of Haberdine or Laberdan (Kabiljo).
Description
Large fish to 2 m, commonly from 30 to 100 cm, with moderately elongated body, compressed and tapering behind, moderately deep caudal peduncle. Head narrowed anteriorly, top of head lacking V-shaped ridge. Mouth moderate or large with either upper jaw or lower jaw slightly protruding in many. Teeth cardiform, subequal, or with those of one series more or less enlarged; teeth on vomer; none on the palatines. Small single barbel on the chin, which is sometimes minute, present in most species.
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All members of the cod family have spineless fins. Most species have two dorsal fins, some have three, others only one. Long dorsal fin well separated into 3 parts; anal fin divided in 2 parts; caudal fin well developed, of about seven rays, truncate to forked; pectoral fins well developed, pointed; pelvic or ventral fins are short, thoracic and located far forward, commonly ahead of the pectorals. The cod family is distinguished from other soft-rayed fishes by the fact that the large pelvic fins are situated under or in front of the pectorals and not behind them as in salmon and herring. Scales very small; lateral line present.
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Species color is variable, usually brownish to olive, or greyish to bluish dorsally, somewhat paler ventrally, belly often white, grey, or yellowish.
Habitats
The cads are generally fishes of cold water, and most of them live close to the bottom. Most species live in cold waters of the Northern Hemisphere, confined to cold temperate to Arctic waters of North Atlantic and North Pacific, with few species in Southern Hemisphere. Most live on or near bottom (a few species pelagic) over continental shelf from nearshore to far offshore, but some occur at depths of 600 m or more; early-life stages pelagic, juveniles of some species found in estuaries and shallow coastal waters. Seasonal inshore-offshore migrations common, some undergo extensive north-south migrations.
Most species voracious and omnivorous predators, mainly bottom dwellers, feeding on small fish, mollusks, shrimp, crabs, squid, sea worms, and various bottom invertebrates.
Spawning
Fecundity in most species high, depending on size of individual; spawning occurs in colder months, usually from late autumn to spring, depending on locality and water temperature. Codfish and other pelagic species in the family produce prodigious numbers of eggs. A 20-pound female may lay 4 to 5 million eggs in a season, and a specimen of 75 pounds may produce more than 9 million eggs. Males spread their milt in the sea around the eggs and fertilize them. The eggs float freely, as do the newly hatched fish. The young are about an inch long before they are strong enough to swim well, and the few that survive manage to get into shallow enough water for them to find refuge, feed, and grow. By the time they are three years old, they weigh roughly 5 pounds.
The Atlantic cod (Gadus morhua) occurs off both the European and North American coasts in cool waters and from near the surface to depths of a thousand feet or more. Smaller fish are generally closer to shore, larger ones remain in deeper water. Cod like cool waters and may sometimes follow cool currents out of their normal range. In winter, for example, they are found as far south as North Carolina.
The Atlantic cod has three dorsal fins and two anal fins. The light lateral line against its dark sides is a distinctive feature. The snout is rounded or cone-shaped on top, the upper jaw projecting slightly beyond the lower. The tail is almost squared or is slightly concave. There are two principal color phases, gray and red; in both, the sides are covered with dark dots.
The Pacific cod (Gadus macrocephalus), also known as gray cod, gray goo, gray wolf, grayest or grayfish, is found on both sides of the Pacific. Off the North American coast. It occurs from Oregon northward, only occasionally straying southward. It has 3 separate dorsal fins, and the catfish-like prominent chin barbel on its lower jaw. The Pacific cod is almost identical to the Atlantic cod, differing only in having slightly more pointed fins. It is somewhat smaller on average.
The Haddock (Melanogrammus aeglefinus), is closely related, and sometimes placed in the genus Gadus, found off both the North American and European coasts in the Atlantic. Haddock are bottom feeders, like cod, travel in large schools, usually found in greatest numbers in water 100 to 500 feet deep. The two most common of the several color variations are grayish green with a dark lateral line and golden brown with a yellow lateral line. Like the cod, the haddock has 3 dorsal and 2 anal fins, but it lacks spots on its body. The first rays on the leading dorsal fin are exceptionally long. Just above and behind each pectoral fin is a large, dark blotch.
Most of the catch is filleted and frozen. Some is smoked, which is called finnan haddie. The largest haddock fishery historically has been off the Grand Banks of Newfoundland and in Europe, in the North Sea south of Spitsbergen.
The Atlantic Pollock (Pollachius virens), has been the most popular of the cod family with anglers. Averaging 4 to 10 pounds in weight (but with some catches weighing more than 30 pounds), the pollock is found on both sides of the Atlantic in cool to cold waters, usually close to shore but commonly netted at depths of 400 to 500 feet. The pollock’s snout is pointed, the lower jaw projecting beyond the upper; the chin barbel is very small or lacking. The broad caudal fin is forked. Because the back and sides are a greenish brown, another name for the pollock is green cod. There are no spots, however, and the lateral line is white.
Pollock are active feeders, preying mainly on small fish but also taking crabs, mollusks, and other small animals. Anglers catch them principally by trolling, using jigs or spoons, but the smaller fish are known also to take artificial flies along inshore waters. They are strong fighters.
Alaska pollock or walleye pollock (Theragra chalcogramma), also known as bigeye pollock, snow cod or tomcod, is a North Pacific species of the cod family Gadidae, related to the common Atlantic pollock species of the same family. Species are widely distributed throughout the North Pacific with the largest concentration in the Bering Sea. Voracious feeders; young feed primarily on invertebrates (especially crustaceans), the adults on fish.
Atlantic Tomcod
The Atlantic tomcod (Microgadus tomcod) and its close relative, the Pacific tomcod (M. proximus), also have three dorsal and two anal fins, which are rounded, as are the long caudal fins. The pelvic fins extend into long filaments that may be sensory in function. These fish are generally olive brown above and lighter below, the sides heavily blotched with black. Tomcod average less than 12 inches in length, and only occasional individuals weigh more than a pound.
Hake
Hake differ from cod in having the second and third dorsal fins joined to make one large fin that typically is indented or notched where the two are joined. Directly below is an indentation on the anal fin. The lower jaw projects beyond the upper, and the chin barbel is either very small or absent. The caudal fin is shallowly forked.
Hake is slow growing fish with a lifespan of about 14 years. It is known to grow to about 115 cm and males and females are very not very easily differentiated. The larger South African Hake is known to prey on young Merluccius paradoxus, and cannibalism is also seen in both species. Both species aggregate to spawn – once in early summer and again in autumn. Hake are predators, feeding on smaller fish and squid. They travel in schools, generally at the edge of the continental shelf or below, down to 2,000 feet. Hake also undertake daily vertical migration – they aggregate close to the bottom in the daytime and then disperse and move higher in the water in the night to feed on fish and plankton. Their eggs contain oil droplets so that they rise to the surface and float in the open sea until they hatch. Compared to cod, the flesh of hake is soft, and thus generally less appealing. Hake have nevertheless been harvested commercially in large quantities.
The South African Hake (Merluccius capensis) is considered the most valuable commercial fish netted off the African coast. It sometimes reaches a length of 4 feet but averages 2 feet or less.
The European Hake (Merluccius merluccius), which is similar in size to the Atlantic and Pacfic whiting, ranges from Norway southward to Africa and occurs also in the Mediterranean. European hake grow to about 100 cm (3 ft) in length and weigh about 3 kg (10 lbs) Males of this species tend to be smaller than the females.
The Silver Hake (Merluccius bilinearis), also known as Atlantic hake or New England hake, and regionally known as whiting is quite popular fish, common species off the Atlantic coast of North America, from Newfoundland south to the Bahamas, north west Atlantic Ocean from Maryland to the Newfoundland Banks, at depths of between 55 and 900 m. They grow to about 30 in (75 cm).
The Pacific Hake (Merluccius productus) is the only representative in the Pacific region, north east Pacific Ocean from northern Vancouver Island to the northern part of the Gulf of California. They have two dorsal fins and a truncate caudal fin, that is is always concave. Their pectoral fin tips usually reach to or beyond the origin of anal fin. Color is metallic silver-gray with black speckling and pure silvery white on the belly. They grow to about 60 cm (2 ft) in length and weigh 1 -2 kg (2-4 lbs).
The White Hake (Urophycis tenuis), ranging from Newfoundland to North Carolina, is a slender fish that may exceed 3 feet in length and weigh more than 30 pounds. The average is about half this size. As in the hake of the genus Merluccius, the second and third dorsal fins are joined. The first ray of the first dorsal is extended into a slim filament, and the caudal fin is rounded. There is a small chin barbel, and the pelvic or ventral fins are reduced to long filaments. The back and sides are reddish, grading into yellowish gray below.
The Red Hake (Urophycis chuss) occurs in the same general range as the white hake, northwest Atlantic Ocean at depths of between 10 and 500 m. The filament of its first dorsal fin is much longer, and the sides are mottled. The maximum size of the red hake is 8 pounds; the average is about 2 pounds.
The Southern Hake (Urophycis floridana), which averages a pound in weight is one of several other species in the genus Urophycis that are about the size of the red hake or smaller. It has dark spots above and behind the eyes and also on the gill covers, and the first ray of the dorsal fin is of normal length. There are round white spots at regular intervals along the black lateral line. The southern hake occurs in the Gulf of Mexico and is sometimes caught on hook and line, particularly in winter.
The Spotted Hake (Urophycis regius) also lacks the long filament on the first dorsal fin, and its scales are larger than in other hakes of the genus Urophycis. The slim pectoral fin is exceptionally long, extending to the anal fin. The spotted hake is the most common species in the mid-Atlantic region. It is seldom fished for but is caught accidentally on hook and line. Commercial fishermen also catch these hake from time to time, but the fishery for hake is not large or well developed.
The b>Burbot (Lota lota), also known as ling, lawyer, eelpout, and freshwater cod, is the only one species of the cod family lives exclusively in freshwater, which is found in deep, cold lakes and streams, sometimes in great abundance, from Alaska southward throughout Canada and in the northern portion of the United States. It occurs also in the cold regions of Europe and Asia. It is sometimes mistaken for some kind of catfish. Its scales are so small that the burbot appears to be naked, like a catfish, and beneath its chin is a single long barbel. The pelvic fins are located far forward, ahead of the pectorals, directly under the throat. There are two dorsal fins. The first is short, the second long and nearly matched in length by the anal fin below. The caudal fin is small. The burbot is white or yellowish orange, mottled with black, but the coloration depends greatly on the chemistry of the water in which the burbot is living. It is not unusual for the burbot to reach a weight of 5 or 10 pounds and to measure 3 feet in length.
Burbot are active predators. In most places they are considered trash fish that are destructive to populations of more desirable species, but there has been some increased interest in sportfishing for them, particularly among ice anglers.
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