Significance To Humans

This species is landed as by-catch in trawl fisheries for shrimps and bottom fishes and may appear in fish markets in some countries of South America. It is relatively small and has limited value in commercial markets, although its flesh is considered good. ♦

Resources

Books

Bohlke, James E., and Charles C. G. Chaplin. Fishes of the Bahamas and Adjacent Tropical Waters. 2nd edition. Austin: University of Texas Press, 1993.

Collette, Bruce B., and Grace Klein-MacPhee. Bigelow and Schroeder's Fishes of the Gulf of Maine. 3rd edition. Washington, DC: Smithsonian Institution Press, 2002.

Gordon, D. J., D. F. Markle, and J. E. Olney. "Ophidiiformes: Development and Relationships." In Ontogeny and Systematics of Fishes, edited by H. G. Moser. Special Publication no. 1. American Society of Ichthyologists and Herpetologists, 1984.

Nelson, J. S. Fishes of the World. 3rd edition. New York: John Wiley & Sons. 1994.

Nielsen, Jorgen G., Daniel M. Cohen, Douglas F. Markle, and C. Richard Robins. FAO Species Catalogue: Ophidiiform Fishes of the World (Order Ophidiiformes). FAO Fisheries Synopsis, vol. 18, no. 125. Rome: Food and Agriculture Organization of the United Nations, 1999.

Robins, C. Richard, and Carleton R. Ray. A Field Guide to Atlantic Coast Fishes of North America. Boston: Houghton Mifflin Co., 1999.

Periodicals

Fahay, M. P. "Development and Distribution of Cusk-eel Eggs and Larvae in the Middle Atlantic Bight with a Description of Ophidion robinsi n. sp. (Teleostei: Ophidiidae)" Copeia 1992 (1992): 799-819.

Resources

Johnson, G. D., and C. Patterson. "Percomorph Phylogeny: A Survey of Acanthomorphs and a New Proposal." Bulletin of Marine Science 52 (1993): 554-626.

Markle, D. F., and J. E. Olney. "Systematics of the Pearlfishes (Pisces: Carapidae)." Bulletin of Marine Science 47 (1990): 269-410.

Suarez, S. S. "The Reproductive Biology of Ogilbia cayorum, a Viviparous Brotulid Fish." Bulletin of Marine Science 25 (1975): 143-173.

John E. Olney, PhD

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Gadiformes

(Grenadiers, hakes, cods, and relatives)

Class Actinopterygii Order Gadiformes Number of families 11

Photo: A hake, or forkbeard (Urophycis blen-noides), in the Mediterranean Sea. (Photo by Sophie de Wilde/Jacana/Photo Researchers, Inc. Reproduced by permission.)

Photo: A hake, or forkbeard (Urophycis blen-noides), in the Mediterranean Sea. (Photo by Sophie de Wilde/Jacana/Photo Researchers, Inc. Reproduced by permission.)

Evolution and systematics

It is important to note that agreement is lacking among ichthyologists as to the composition, origins, hierarchy, or relationships within the Gadiformes. Nor is there agreement concerning external relationships of members of this rather arbitrary group of fishes. There are no groupings of characteristics that can be assigned to the Gadiformes alone; therefore, synapomorphies (derived characters shared by all members of the group in question) have not been identified for all members of the order to the exclusion of nonmembers. Important recent contributions concerning the phylogeny and systematics of the order Gadiformes include Marshall and Cohen 1973; Markle 1982; Cohen 1984; Fahay and Markle 1984; Cohen (Ed.) 1989 (and several contributions therein); and Cohen et al. 1990. To quote Cohen et al. "The assignment to the order of many species is presently as much a matter of ichthyological convention as it is a result of logic." For the purposes of the present volume, we ground our classification on a taxonomic model proposed by Cohen et al. 1990, wherein taxa are listed alphabetically, in order not to suggest phylogenetic relationships. However, we elevate several genera or groups of genera to family status, not arbitrarily, but based on a consensus of several studies. Those 11 families are listed below (alphabetically) with a tally of genera and species presently understood to be contained in each.

• Bregmacerotidae (1 genus, 15 species)

• Euclichthyidae (1 genus, 1 species)

• Macrouridae (19 genera, 300+ species)

• Merlucciidae (3 genera, 18 species)

• Muraenolepididae (1 genus, 4 species)

• Steindachneriidae (1 genus, 1 species)

This listing departs from certain other studies presently available in the following ways: 1) The Gadidae, Lotidae, and Phycidae are usually considered subfamilies (Gadinae, Loti-nae, and Phycinae) of the family Gadidae in those studies; 2) the genus Steindachneria is included in the Merlucciidae in some other studies rather than being elevated to full family status; and, 3) the Merlucciidae is included in an expanded family Gadidae in some other studies. The listing above is used here largely because it is the result when ontogenetic evidence is considered. It also better emphasizes the diversity present within the order Gadiformes.

Physical characteristics

The families listed above are diagnosed as follows:

• Bregmacerotidae: These species are sometimes called unicorn cods. The first dorsal fin is a single, elongate ray arising from a position over the head. The second dorsal and anal fins are long mirrors of each other; there are longer rays at the anterior and posterior ends forming rounded lobes. The elongate, trailing pelvic fin rays arise from the throat position and extend well beyond the anus. The lateral line is high on the body and is parallel to the dorsal margin of the body. There are no chin barbels.

• Euclichthyidae: The single species is called the eu-cla cod. The body is long and tapering to a very narrow caudal peduncle. It has a large mouth and no chin barbel. The first dorsal fin is short and high, nearly touching the second dorsal fin, which is shorter and extends the length of the body to the caudal fin. The anal fin is long, with a greatly enlarged anterior lobe. The caudal fin is small and asymmetrical, with the lower rays being longest. Each pelvic fin is comprised of four separate, filamentous rays.

• Gadidae: This family includes cods, haddock, pollock, tomcod, and others. There are three separate dorsal fins and two separate anal fins. The dorsal and anal fins are either touching at their bases or separated by gaps. A chin barbel is usually present. There are pelvic fins, sometimes with one or more elongate rays.

• Lotidae: This includes the tusk (or cusk), burbot, and lings. The dorsal fin is single (in Brosme), or there is a short first dorsal followed by a long second dorsal in Lota and Molva. The single anal fin has a long base and includes many fin-rays. There is a well-developed chin barbel. The pelvic fins are normal and are not modified into elongate rays.

• Macrouridae: This includes rattails and grenadiers. The head and trunk are short, and the tail is compressed and greatly elongate, tapering to a point and lacking a caudal fin (with one exception). The chin barbel is usually present. The head and mouth shape and size vary. Eye size varies, but eyes are usually very large. There are two dorsal fins; the first is high, often including spinous anterior rays. The second dorsal and anal fins are long, meeting at the tail tip. The pectoral fins are narrow based and positioned high on the trunk. The pelvic fins are narrow based, thoracic to jugular in position, and comprised of 5-17 rays. Some species have a light organ on the mid-ventral line of the trunk. The benthic species have a well-developed air bladder, and the bathy-pelagic species lack an air bladder.

• Melanonidae: This includes the pelagic cod. It is small, not exceeding 5.9 in (15 cm). The body is long, tapering to a very narrow caudal peduncle. The head has numerous fleshy ridges. There is no chin barbel. The dorsal and anal fins are single and long-based. A slight gap separates the caudal fin from the dorsal and anal fins.

• Merlucciidae: This includes hakes and grenadiers. The genus Merluccius (hakes) has a large head (1/3 to 1/4 of body length), with a large, oblique mouth. The lower jaw is longer than the upper. There are two separate dorsal fins, with the first being short-based, high, and triangular. The second is long and partially divided by a notch in midsection. The single anal fin is similar in shape to the second dorsal. There are pelvic fins with seven rays. The genera Ly-conus and Macruronus are characterized by long, tapering bodies lacking caudal fins. The dorsal fin is single with elevated anterior portion in the former, double with short first dorsal followed by very long second dorsal in the latter. Both have large, oblique mouths. Both have normal pelvic fin without elongate rays. The pectoral fin includes elongate rays in Lyconus.

• Moridae: This includes the moras. The body tapers to a very narrow peduncle. There are two or three dorsal fins, and one or two anal fins. The pelvic fins are thoracic and are wide apart at the bases. The caudal fin is symmetrical and separated from the dorsal and anal fins by a gap.

• Muraenolepididae: This includes moray cods. The body is long and compressed. The head is small with a chin barbel. The gill openings are restricted and do not open above the pectoral fin bases. There are two dorsal fins, the first comprised of a single, slim ray, and the second long-based and merging with the caudal fin. The anal fin is single, also merging with the caudal fin. The pelvic fins are thoracic with five rays, 2-3 of which are elongate and not attached to others. The lateral line ends at mid-body.

• Phycidae: This includes hakes and rocklings. There is a single anal fin. There are two dorsal fins, the first either short-based and moderate in height, or comprised of a single elongate, filamentous ray followed by many, very short hair-like rays. There is a single chin barbel, or 2-4 barbels on the snout as well as on the chin. The pelvic fin is normal in shape and length, or with two very elongate rays, often reaching the level of the anus.

• Steindachneriidae: This includes the luminous hake. The body is long, compressed laterally, and tapers to a point. The head is compressed laterally, and the mouth is very large. There are two dorsal fins, the first with one spine and 7-9 rays, the second with 123 or more rays. The anal fin is comprised of 123 to more than 125, very short rays. The first ray of the pelvic fin is elongate and filamentous. The anus is between the pelvic fin rays and is separated from the urogenital opening just anterior to the anal fin. A purplish, striated light organ covers the lower body and sides of head.

Distribution

The distribution of gadiform fishes varies by family, but in general, gadiforms are residents of cool water, therefore occurring throughout the water column in high latitudes, but mainly in deeper layers of tropical waters, where temperatures are lower (a phenomenon known as "tropical submergence"). Members of the gadiforms are primarily marine, but a few freshwater or estuarine species occur. The distribution of each family was summarized in Marshall and Cohen (1973). Breg-macerotids differ somewhat from the rest of the order in their distribution in tropical and subtropical seas. The single euclichthyid species occurs in Australian and New Zealand waters, where it lives near the bottom in deep water.

Gadids are centered in continental shelf waters of the temperate and boreal North Atlantic, although a few members

Polynemus Larvae

Examples of larval stages of gadiform fishes: 1. Moridae, Gadella maraldi; 2. Macrouridae, Gadomus sp.; 3. Macrouridae, Coryphaenoides sp.; 4. Muraenolepididae, Muraenolepis sp.; 5. Melanonidae, Melanonus sp.; 6. Merlucciidae, Merluccius productus; 7. Steindachneriidae, Stein-dachneria argentea; 8. Bregmacerotidae, Bregmaceros mcclellandi; 9. Gadidae, Gadus morhua; 10. Lotidae, Brosme brosme; 11. Phycidae, Uro-phycis chuss. (Illustration by Bruce Worden)

Examples of larval stages of gadiform fishes: 1. Moridae, Gadella maraldi; 2. Macrouridae, Gadomus sp.; 3. Macrouridae, Coryphaenoides sp.; 4. Muraenolepididae, Muraenolepis sp.; 5. Melanonidae, Melanonus sp.; 6. Merlucciidae, Merluccius productus; 7. Steindachneriidae, Stein-dachneria argentea; 8. Bregmacerotidae, Bregmaceros mcclellandi; 9. Gadidae, Gadus morhua; 10. Lotidae, Brosme brosme; 11. Phycidae, Uro-phycis chuss. (Illustration by Bruce Worden)

have wandered into cool waters of the North Pacific and some species are circumpolar. Three species in Gadus, including the Atlantic cod, occur circumboreally, extending into Arctic waters north of Europe, where they are found as deep as 1,640 ft (500 m). Melanogrammus aeglefinus, the economically important haddock, is restricted to the North Atlantic where it occurs off the northeastern United States and northern coasts of Europe. Microgadus includes the tomcod, a brackish and freshwater species found along the east coast of Canada and the northeastern United States. Pollachius contains two species, one of which is restricted to the eastern North Atlantic, the other occurring on both sides of the North Atlantic. Theragra chalcogramma, the Alaska pollock, is a North Pacific species that is widely distributed in temperate to boreal waters. Fishes in the family Lotidae are also centered in the North Atlantic, and one genus (Lota) has successfully invaded fresh waters of northern Europe and northern North America.

Members of the speciose family Macrouridae (rattails and grenadiers) occur primarily in deep-water habitats throughout the world's oceans (except for the Arctic). Almost all deep oceanic basins contain a macrourid fauna, and it has been estimated that in the Pacific, members of this family comprise the greatest vertebrate biomass between certain depth strata (Cohen et al. 1990). More macrourid species occur in tropical waters than at high latitudes. Several have very restricted ranges, but the deeper-living species are more widely distributed.

The two species in the family Melanonidae are not well-known or often collected. One species is circumantarctic, the other circumglobal in tropical/subtropical waters. Merlucci-ids occur in continental slope and deep-shelf habitats along coastlines throughout the world. The several species in Mer-luccius are found on both sides of the Atlantic Ocean, the eastern Pacific Ocean, and off southern New Zealand. The enigmatic genus Lyconus has been found (rarely) in both the North and South Atlantic oceans. One genus (Macruronus) is restricted to subantarctic waters.

The family Moridae is found in all oceans. Most species have very restricted ranges, although Antimora microlepis occurs in much of the entire North Pacific. Four species in the family Muraenolepididae all occur in the Southern Ocean, near the bottom in cold-temperate waters. Each species is restricted to waters around capes or groups of islands surrounding Antarctica.

The Phycidae are bottom-living fishes with a center around the coastlines of the North Atlantic, but with a few Southern Hemisphere species. Gaidropsarus exhibits a center of abundance in the northeast Atlantic Ocean, but also extends to Japan, New Zealand, and South Africa. Phycis contains two species, which are benthopelagic along the eastern North Atlantic Ocean coast. The several species in Urophycis are distributed in the western Atlantic Ocean from Canada through Argentina. Enchelyopus cimbrius is found on both sides of the North Atlantic, where it occurs along the east coasts of the United States and Canada, the Gulf of Mexico, southern Greenland, Iceland, and the north coasts of Europe. Finally, the monotypic family Steindachneriidae (Steindachneria argentea) is restricted to fairly deep waters of the Gulf of Mexico, Caribbean Sea, and continental slope waters off the eastern United States.

Habitat

Habitats occupied by gadiforms vary by family and by genera. Bregmacerotids occur epi- or mesopelagically in open-oceanic waters, extending at times to shallow, coastal habitats. Some have occasionally been found in estuaries. Euclichthys polynemus, the sole species in the family Euclichthyidae, occurs benthopelagically in depths of 820-2,625 ft (250-800 m).

Most species in the Gadidae occur demersally (on the bottom) or benthopelagically. Very few (e.g. Gadiculus argenteus) are pelagic (live in the water column off the bottom). The demersal species occur over a variety of substrates (rock, sand, mud, gravel, or shell debris), most prefer one over the others, and some undertake seasonal migrations between habitat types. The two species in Pollachius are pelagic, and sometimes form large wandering schools that migrate seasonally. The many species in the Macrouridae are found in all oceans, where they occur over very deep bottoms, including the deep ocean basins. The deepest-occurring species occur at greater than 3.7 mi (6,000 m), and few occur shallower than 328 ft (100 m). Melanonids are widely distributed in open ocean meso- and bathypelagic depths between tropical and sub-antarctic waters.

Most species in the genera Merluccius and Melanonus occur over continental shelves or upper continental slopes. Favored bottom types occupied by species in the genus Merluccius range from sandy to muddy. The ill-known genus Lyconus is pelagic and occurs in open waters of the Atlantic Ocean.

Morids are pelagic to benthopelagic, and occur from shallow coastal habitats (rarely including estuarine habitats) to deep oceanic waters. Favored bottom habitats range from soft to hard bottoms, and from sand to mud. Muraenolepidids live near bottom in moderate depths in waters surrounding Antarctica. Phycids are demersal fishes living on a variety of substrates ranging from mud to sand to shell debris. Finally, Steindachneria argentea lives in the lower water column over soft bottoms on the deeper parts of the continental shelf and upper continental slope.

Habitat requirements of most gadiforms vary according to their life-history stage or age. It is impossible to propose a generalized model of those varying habitat requirements because each family and each species exhibits its own pattern. For example, within the Phycidae, the white hake, Urophycis tenuis, spawns beyond the continental shelf off the northeastern United States, and the fertilized eggs rise into open ocean layers near the surface in an area known as the "Slope Sea." The larvae hatch and develop into a pelagic-juvenile stage, strongly associated with the surface. As they grow they migrate across the entire breadth of the continental shelf toward shore. They arrive in estuaries as small juveniles and spend one season there growing rapidly, finally leaving the estuary at sizes of about 6 in (15.2 cm) at the end of the summer. One- and two-year-olds may remain segregated from older fish by virtue of their occupation of shallower bays and near coastal waters. Subsequently they mingle with the rest of the adult population on deeper parts of the continental shelf, with seasonal migrations into shallower waters. The white hake's range of habitat requirements, therefore, extends from the estuary, across the breadth of the continental shelf, to the upper part of the continental slope, and also includes the entire water column, from surface to bottom (Fahay and Able 1989).

Another phycid, Urophycis chuss, the red hake, has very specialized habitat requirements. The fertilized eggs occur in near-surface layers of oceanic waters off the northeastern United States. After hatching, the developing larvae occupy the same general layers. The larvae gradually acquire silvery coloration and go through a pelagic-juvenile stage when they occur epipelagically or neustonically, within a few inches of the surface, often associated with floating weed or debris. After about two months of this pelagic existence, red hakes settle to the ocean bottom and seek shelter in a variety of structured habitats including beds of clam shells, anemone or polychaete tubes, depressions made by fishes or crustaceans, or most frequently, beds of scallops, Placopecten magellanicus. The young fishes have been found hiding under scallops, but more frequently they enter into an inquiline association with them whereby they live within the scallops' mantle cavities. The young fish remain in this association through their first winter, finally emerging when they are about 4 in (10.2 cm) long in the spring, and then they remain in coastal or estu-arine waters through the next summer. When waters cool in the fall, they join older fish in an offshore migration toward the edge of the continental shelf, where they spend their second winter. Their required habitats, therefore, include the entire water column from surface to bottom, specific beds of invertebrate hosts on the substrate, and the entire breadth of the continental shelf from estuary to shelf edge depending on the season (Able and Fahay 1998).

The Atlantic cod also has habitat requirements specific to its life history stages. The fertilized eggs are pelagic and occur in waters overlying bays, the continental shelf, and important banks and shoals, (e.g. eastern Georges Bank, Grand Banks). Larvae are also pelagic and drift slowly away from spawning areas as they develop. The early juveniles descend to the bottom when they are about 2 in (5.1 cm) long and set tle on pebble-gravel deposits on important banks, such as the northeast peak of Georges Bank. After settlement, young fishes appear to favor vegetated habitats (such as eelgrass) in coastal embayments, where they avoid predation by older cod, as well as other predators. After two or three years of segregation from adults, these one- and two-year-olds finally join the adult population. Adults exhibit seasonal movements associated with depth and temperature fluctuations, generally moving into shallower waters during summer and retreating to deeper waters for the winter. Data are available demonstrating habitat preferences based on depth, temperature, and salinity, but surprisingly little is known about bottom types favored. Rocky, pebbly, sandy, and gravelly have all been used to describe cod haunts.

Behavior

In general, gadiform fishes are demersal and highly pis-civorus, but there are exceptions to these characterizations. These fishes occur primarily in colder waters, but many exhibit seasonal migrations associated with reproduction or the quest for important prey items. Observations on actual spawning behavior are few, and data on day-night differences in their behavior are also few. Feeding behavior also varies seasonally for many species, with a characteristic pattern involving cessation of feeding activity during spawning seasons.

Feeding ecology and diet

Many gadiform fishes feed on prey items occurring in the substrate, and they are assisted in their search for food by the presence of tactile barbels on their chins. Barbels are well developed in almost all of the gadids, phycids, lotids, macrourids, morids, and muraenolepidids, all of whom feed actively on benthic items. Conversely, the diet of one of the most pelagic of the gadids, the pollock (Pollachius virens), consists primarily of euphausiids and Atlantic herring, and its much-reduced barbel reflects this focus on pelagic prey. Certain other pelagic gadiforms, such as the melanonids, bregmacerotids, and Euclichthys polynemus, lack chin barbels, and although their food habits are not well studied, it can be assumed that their important diet items are also pelagic.

The phycid hakes Urophycis chuss and U. tenuis (red hake and white hake, respectively) have similar food habits, although they do not always occur in the same habitats. Both species focus on crustaceans and eat other fishes only secondarily. Annelids, molluscs, and all other prey constitute a minor fraction of their diets. Their feeding behavior also takes advantage of sensitive pelvic fin rays, which are deployed in advance of the fish and aid in the search for prey through their tactile abilities. The Atlantic cod is primarily a piscivore. Among the fishes it consumes, the herring, Clupea harengus, is perhaps the most important, but redfish, mackerel, and smaller cod are also important prey items, and diet components are likely to vary between different study sites. Certain Newfoundland studies have found the capelin to be critically important. Cod also eat crabs, and in some studies crustaceans have been identified as more important than fishes. The haddock, Melanogrammus ae-glefinus, has slightly different food habits than its relative, the cod. Although it focuses on crustaceans as a major dietary component, fishes are unimportant in the remainder of its diet, while polychaetes and echinoderms are secondarily important. The diets of macrourids are highly variable and consist of a wide range of fishes and benthic and pelagic invertebrates. Merlucciids are voracious predators, and the several species of Merluccius are highly piscivorous.

Specific information concerning the species that prey on gadiform fishes is lacking for most species. Adults of larger, commercially important species (cod, haddock, etc.) are probably only preyed upon by sharks, billfishes, and other large predators, and their most important predator is undoubtedly man. Young stages of all species, however, face predation by a large number of species, and this plays a large part in determining year-class strength. Some of their predators are larger members of the same species.

Reproductive biology

More is known about reproduction and egg and larval development in the families Gadidae and Merlucciidae, for those two contain commercially important species that have received the most attention. Gadiform fishes, in general, release masses of eggs that are then fertilized externally. Almost all of those eggs are pelagic (although little is known about reproduction in the deep-water species). The Atlantic cod is one of the world's most fecund fishes. A female of 11.0 lb (5 kg) is capable of producing 2.5 million eggs, and larger females can produce more. The haddock is not far behind. A female just under a meter in length can produce close to 2 million eggs. Eggs of gadiforms range from about 0.02 in (0.5 mm) in diameter in some morids and phycids, to about 0.08 in (2.0 mm) in certain gadids and macrourids. The chorion (outer shell) is smooth in most, but it may have a hexagonal pattern in the Macrouridae. Most gadiform eggs have a single, small oil globule, although eggs of the gadids lack an oil globule. Early life history stages are known for fewer than a third of the species described in the Gadiformes, but some descriptions are available for each family. Gadiform larvae exhibit a diverse array of shapes and specializations. According to Fahay and Markle (1984), "There does not seem to be any character unique or diagnostic for young gadiforms. The features of body shape, anus morphology, and pelvic fin development in combination with specific familial characters appear to be the most useful for initial identification. Transformation is gradual and direct with no striking changes in ontogeny." The gut of most gadiform larvae coils early in ontogeny, and combined with a tapering postanal region and rounded head, contributes to an overall tadpole-like appearance. It has not been documented in all gadiform families and is not always easily observed, but very young gadiform larvae have an anus that exits laterally through the finfold rather than at its edge as in most fish larvae. Another characteristic of gadiform larvae is that some secondary caudal rays develop before some primary rays (in forms that have a caudal fin).

Conservation status

The IUCN lists three gadiform species: Physiculus hele-naensis is categorized as Critically Endangered, and Gadus morhua and Melanogrammus aeglefinus are categorized as Vulnerable. There are no gadiform fishes listed by the United States as endangered or threatened. However, among the factors threatening the sustainability of viable populations of gadiform fishes, overfishing figures high, especially regarding the Atlantic cod, Gadus morhua. In some important areas, for example eastern Canadian provinces, the cod is commercially extinct, meaning its population levels are so low that it can no longer sustain a fishery. The loss of various marine habitats, critically important to the survival of young fishes (as well as older stages), is often cited as contributory to fish populations' declines. For almost all fishes, our knowledge of the critical function of these habitats is lacking or superficial, and increased research in these areas is often cited as necessary for proper management of marine resources.

Significance to humans

Certain gadiforms are among the world's most commercially important fishes. In the late 1980s, for example, some 15,101,665 tn (13,700,000 metric tons [t]), representing fully 17% of the world's landings of marine fishes, were comprised of gadiforms. Of this total, 95% was contributed by the Ga-didae (cods and their relatives), followed by the merlucciids, the macrourids, and morids.

The Atlantic cod has been an important fishery for centuries, and this fishery has actually influenced the development of western civilization in countries around the perimeter of the North Atlantic Ocean (Kurlansky 1997). It is said that when John Cabot arrived in Newfoundland waters, suppos edly the first European explorer to do so, he was greeted by a well-established fleet of Basque fishermen, who in turn had been fishing for cod in Grand Banks waters for centuries before that. In the days before refrigeration, during the time when the Catholic Church mandated the eating of fish on Fridays and holy days, a good-tasting, lean fish that dried well was in a position to dominate the European markets. The Basques were pioneers and masters both in catching and processing cod and therefore enjoyed a commanding position in the world's economy. Despite the heavy fishing pressure exerted on the cod stocks during past centuries, it sustained a huge fishery until the late 1900s, when increased exploitation, based on increasingly efficient fishing methods (possibly combined with changing environmental trends), finally contributed to the collapse of the cod population. The collapse of the stocks off Labrador and Newfoundland has had particularly devastating and tragic economic consequences in eastern Canada, where the effects have been compared to the Great Depression during the 1930s in the United States.

Other gadiforms are also the basis for valuable fisheries. The Alaska (or walleye) pollock, Theragra chalcogramma, contributes more to the world's fisheries than any other demersal fish species, of any family. The total annual landings of this fish in the late 1980s reached 7,389,750 tn (6,703,868 t). The merlucciids (hakes of the genus Merluccius and two species of Macruronus) were once considered trash fish, but now 11 species are being exploited. In the late 1980s, 2,180,192.1 tn (1,977,837 t) were harvested, making them the second most commercially important family of gadiforms after the Gadidae.

E.S.ÙAMSTRA©2002

1. Roundnose grenadier (Coryphaenoides rupestris); 2. Luminous hake (Steindachneria argentea); 3. Atlantic tomcod (Microgadus tomcod); 4. Alaska pollock (Theragra chalcogramma); 5. Burbot (Lota lota); 6. Haddock (Melanogrammus aeglefinus); 7. Silver hake (Merluccius bilinearis); 8. White hake (Urophycis tenuis); 9. Atlantic cod (Gadus morhua); 10. Red hake (Urophycis chuss); 11. Pollock (Pollachius virens). (Illustration by Emily Damstra)

Species accounts

Atlantic cod

Gadus morhua

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