Arctic flounder
Polar flounder fish is one of the important commercial fish in the Arctic Ocean and surrounding seas.
Content
- What kind of fish is the polar flounder?
- What does a polar flounder look like?
- Where are Arctic flounder found?
- Where does the Arctic flounder live?
- How do Arctic flounder spawn?
- What does Arctic flounder eat?
- Industrial importance of polar flounder
What kind of fish is the polar flounder?
Arctic flounder Latin name Liopsetta glacialis, also known as the Christmas flounder, eelback flounder and Polar plaice. Arctic flounder is the coldest-water flounder that inhabits the Arctic seas.
What does a polar flounder look like?
The polar flounder differs from other species of flounder in the absence of bony tubercles at the base of the fins and the presence of a blunt, rough ridge behind the eyes. As a rule, polar flounder is a medium-sized fish that can grow up to a maximum of 35 cm.
Where are Arctic flounder found?
In Russia, polar flounder inhabits the northern seas: Barents, White, Kara, East Siberian, Bering and Okhotsk. Outside of Russia, polar flounder is found off the coast of Norway, Iceland, Canada and Alaska.
Where does the Arctic flounder live?
In the sea it is found almost everywhere in its coastal zone; juveniles enter rivers.
By nature it is an arctic (cold-loving) fish, and by its lifestyle it is bottom-dwelling. It inhabits places with soft muddy soil, into which it burrows in case of danger. Polar flounder practically does not migrate; as a rule, it does not leave the waters of the bay, spending its entire life in it. It can migrate with the ebb and flow of the tides, moving closer to the shore and moving away from it.
From the beginning of spring until the autumn cooling of the waters, juveniles of polar flounder are constantly found in river mouths, pre-estuarine spaces and in coastal shallow waters, at depths of up to 5 m. Here they accumulate for fattening, and in winter they migrate to greater depths. -
Adult polar flounder stay further from the shores and, during fattening, migrate from place to place over short distances. In winter, adult Arctic flounder migrate to their breeding grounds.
How do Arctic flounder spawn?
Female polar flounder grow faster than males, but males mature faster - in the second year of life (with a body length of 8-11 cm), while female polar flounder mature in the third year of life, when the body length reaches 9-14 cm.
In the Barents Sea, polar flounder matures later, in the fourth or fifth year of life.
Polar flounder breeds in winter (January) under ice, at a depth of 5-10 m, in places with a well-defined current, at negative temperatures (-1.2, -1.6°) and at relatively high salinity (27-28% o). The spawning grounds of polar flounder are shared with navaga, cod and other winter-spawning fish. The fertility of polar flounder ranges from 31 to 230 thousand eggs, and in the Barents Sea from 52 to 203 thousand eggs.
Polar flounder caviar is small, the diameter of the eggs is from 1.2 to 2.6 mm, transparent, floats in the water column, its development occurs in winter conditions, at negative temperatures.
The larvae and eggs of polar flounder, like all flounder fish, are pelagic and are transported by currents over long distances, which contributes to the wide distribution of polar flounder.
What does Arctic flounder eat?
Arctic flounder begins to fatten in the spring, several months after spawning. Its food includes small bivalves and gastropods, sea worms, decapods, amphipods, larvae of aquatic insects (caddis flies, etc.), ascidians and other invertebrates. Occasionally, herring caviar is found in the stomachs of flounder. Competitors of polar flounder in food are other species of flounder.
Arctic flounder grows rapidly during the warm period of the year - from May to September; in winter, growth almost stops.
Industrial importance of polar flounder
Polar flounder is a small fish, usually caught as bycatch when fishing for other fish species. In some regions it occupies a significant place in catches. For example, in the White Sea, 70% of all flounder catch is polar flounder.