 | FAO/SIDP Species Identification Sheets |
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| Eleginus gracilis (Tilesius, 1810) |
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| FAO Names |
EN - Saffron cod; FR - Morne boréale; SP - Bacalao del Artico.
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| Scientific Name with Reference |
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Gados gracilisTilesius, 1810,
Mem.Acad.Sci.Petersb., 2:354 |
| Synonyms |
-
Gadus wachna Pallas, 1811; -
Eleginus navaga gracilis ,Schmidt, 1904.
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| Diagnostic Features |
| 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. |
| Geographical Distribution |
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.
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| Habitat and Biology |
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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.
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| Size |
| Reaches at least 55 cm total length. |
| Interest to Fisheries |
| Total production for Eleginus gracilis. | Total capture for Eleginus gracilis. |
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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.
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| Local Names |
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| Navaga. |
| Literature Reference |
| Svetovidov (1965); Safronov (1981);
Wolotira (1985). |
| Remarks |
| Taxonomic problems remain to be solved. |
| Source of Information |
| Russell, B.C., 1990. FAO species catalogue.
Vol. 12. Nemipterid fishes of the world. (Threadfin breams,
Whiptail breams, Monocle breams, Dwarf monocle breams and
Coral breams). Family Nemipteridae. An annotaded and
illustrated catalogue of Nemipterid species known to date.
FAO Fish. Synop., (125)Vol.12:149 p. The "Interest to
Fisheries" section has been updated according to recent
FAO fishery statistics. |
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