| ||Gadus wachna Pallas, 1811|
| ||Eleginus navaga gracilis Schmidt, 1904|
|En - Saffron cod, Fr - Morne boréale, Sp - Bacalao del Artico.|
3Alpha Code: SAF Taxonomic Code: 1480401202|
|Scientific Name with Original Description|
|Gados gracilis Tilesius, 1810, Mem.Acad.Sci.Petersb., 2:354.|
|Expanded parapophyses beginning on about vertebral centrum 9 or 10 swollen and hollow, containing outpouchings of the swimbladder;
gill rakers 14 to 25.
Colour: dorsally dark grey-green to brown,mottled; pale ventrally.
|North Pacific from the Yellow Sea in the southwest to Sitka in the southeast. Beyond the Bering Strait in the Chukchi Sea and east to Dease Strait (south coast of Victoria Island). Precise delimitation of the range depends on additional taxonomic study.|
|Habitat and Biology|
|Occurs in shallow coastal waters at less than 60 m depth in the Arctic and western Pacific, and at less than 50 m depth in the northeastern Bering Sea and western Alaska, Norton Sound.It has been found, however, off northern Japan, on the continental shelf edge at 200 m depth.The Saffron cod also enters brackish and even fresh waters, occurring quite far up rivers and streams, but remaining within regions of tidal influence.Migrations are not extensive. The juveniles are not migratory and stay in shallow water throughout the year whereas adults undertake restricted seasonal migrations associated with spawning, feeding and changes in wate temperature. The migration pattern could be summarized as winter inshore and summer offshore (or less inshore):|
in early winter, the fish move from the coast or estuaries into adjacent sand-pebble areas for spawning.
After spawning, they return to silty bottoms or estuarine areas where they feed.They spend the winter under the ice cover and in early spring, when the water warms up, they move offshore to the cold and highly saline waters of the open sea. However, the southern Kuril population spends the autumn-winter period in the open sea at depths of 100 to 200 m because the absence of temperature conditions necessary for spawning in August-October in the coastal shallow zone compels the fish to migrate into colder waters.
The Saffron cod begin to mature during their third year of life in Norton Sound, western Alaska. Similar observations made in the western Pacific, northern Tatar Strait, and northern Sea of Okhotsk report the first maturity to occur at 2 to 3 years of life for both sexes. Fecundity varies with geographical region. It decreases from east to west in the European Arctic and from south to north in western Pacific waters. Furthermore, individual fecundity increases with body length, weight and age. in the Gulf of Sakhalin, a two year-old fish (17 cm length) has a minimum fecundity of 4 900 eggs while a 9 year-old individual (47 cm length) in the Gulf of Terpenie can lay a maximum of 680 000 eggs. Thus, the maximum fecundity is 139 times higher than the minimum. For example, a 20-35 cm fish along the USSR Pacific coast (Tatar Strait) has an estimated fecundity of 29 000-124 000 eggs. The Saffron cod spawns once a year, 5 to 7 times in its life, and sometimes even 9-10 times for those fish that live up to 10-14 years. Throughout its distribution area, spawning occurs during January-February in coastal zones of bays and inlets, on sand -gravel substrate and in strong tidal currents, at depths of 2-10 m, with the exception of the Gulf of Terpenie stock that spawns at depths of 25-32 m. There are indications that the eggs are adhesive. Although spawning occurs at the same temperatures and salinities, larvae hatch out in early spring (April-May) in the Arctic or northernmost portions of the western Pacific, and somewhat later (during warming) in waters farther south, such as the Sea of Japan.
The growth rate differs by sex and depends on the amount of forage available. Highest growth rates occur in fish that mature earlier. Generally speaking, growth is relatively slow; it is somewhat faster in the western Pacific stocks (except in parts of the Sea of Okhotsk, where it is slow in comparison with some Arctic stocks) than in the Arctic ones, although they die younger. In the western Pacific distribution of the species, the size of a 3 year-old fish varies from 18.8 to 35.4 cm (mostly 29-35 cm), while in the Barents and Kara seas, it ranges between 16.5 and 20-7 cm. An 8-9 year-old fish in the western Pacific is about 53 cm long while the largest specimen found in Arctic waters was 44 cm . The rate of natural mortality is high, 60-80% annually, and less than 1% of the stock survives past 5 years. The maximum age decreases southward: 11-12 years in Yama inlet and the Gulf of Terpenie; 9-10 years in the other regions of Sakhalin; 7-8 years in Gulf of Peter the Great and off the southern Kurils.Juveniles and adults are opportunistic epibenthic feeders; juveniles feed on fish, mysids, decapods, and amphipods. Feeding starts in summer and goes on until the winter spawning. It is then reduced and resumes in mid-winter after reproduction.
|Reaches at least 55 cm total length.|
|Interest to Fisheries|
|Taken commercially in many areas of the northwestern Pacific and harvested for almost 100 years. Until 1973, total catches fluctuated between 6 600-22 300 t annually, they increased continuously in recent years to an average of 39 000 t/year between 1977 and 1980. The major fishing grounds are in the western North Pacific: Peter the Great Bay, Sakhalin region, Sea of Okhotsk and Kamchatka waters. Fishing is carried out during late autumn and winter by the USSR and, in Norton Sound, by Alaskan fishermen- Fishing gear used are not highly mechanized and include hook and line, beach and danish seines, gill nets, hoop-nets, fyke nets, and trawls. The catch reported for 1987 in the FAO Yearbook of Fishery Statistics is 27 929 t, all taken in the northwestern Pacific by USSR. The catch reported for 1996 in the FAO Yearbook of Fishery Statistics is 21 110 t, all taken in the northwestern Pacific by USSR. The size of the saffron cod does not permit its substitution into existing Pacific cod and walleye pollock markets and costs would not permit it to be profitably used in the pet food industry. The total catch reported for this species to FAO for 1999 was 47 032 t. The countries with the largest catches were Russian Federation (47 032 t).|
It is used for human consumption in USSR, fresh or frozen.
|Taxonomic problems remain to be solved.|