Status. Rare endemic subspecies of Eastern Siberian golden carp, presented at the North-East of Russia and in marginal populations of Chukotka on the eastern limit of the range.
Distribution. Range of the species is extensive and large areas of Eurasia. Yakut subspecies distributed in rivers Lena, Yana (acclimatized), Indigirka, Kolyma, and the lakes headwaters. Urak on the mainland coast of the Sea of Okhotsk. In Chukotka rivers – only Bilibino district – lower and middle reaches of the Small and Large Anyuev, Omolon. Fossils found in carp Late Quaternary sediments from the river to the east. Kolyma on about. Ayon in Chaun Bay.
Morphological description. D II-IV 12-18 (usually III-IV 15-17), A II-IV 5-7 (III 5-6), PI (12) (13) 14-17, VI 5-8 (7-8 ) often incomplete lateral line with 5-7 proboden-governmental scales in the lateral line complete (27) 28-34 (35) (usually 29-32) scales, scales large, cycloid, plotnosidyaschaya, vertebrae 25-34 (28 – 31), gill rakers 35-54 (40-47). Pharyngeal teeth row, laterally compressed, with 4 teeth in each row. The head is small, the mouth small final. The trunk is high, strongly flattened laterally. Dorsal fin long, caudal peduncle short, tall tail fin slabovyemchaty. At the last unbranched rays of dorsal and anal fins are numerous (almost the entire beam) small teeth. The back of the swim bladder elongated oval. On the gill cover and scales radial bone grooves ("sculpture"). The body color is mostly copper-red in color, with occasional aberrant individuals in color (gray, whitish-pink), the peritoneum is a light-gray, rarely black.
Habitat and biology. In Kolyma basin poorly studied species. Typical freshwater, mainly lake, resident fish. It inhabits the floodplain and terraced lakes, overgrown higher aquatic vegetation, and lives in the oxbows and channels with a slow current. Carries a significant shortage of oxygen, so can not be translated into zamornyh lakes. The entire life cycle takes place in the aquatic habitat.
Becomes sexually mature 3-5 year of age with a body length of females 16,8-20,5 (17.9) cm, weight – 66,0-102,0 (82.2) g, males – 12.2 -17 0 (14.5) and 34,0-74,0 cm (53.4), the spawning portions. Home spawning varies depending on climatic conditions of the year, but usually occurs in mid-to late June, when the average water temperature exceeds 12-14 ° C. In populations predominate females – up to 80-90%, they are also larger than males the same age. Spawning occurs in 3-4 hours with intervals of 10-12 days and lasts until September. Spawning grounds are located in the coastal lakes with a depth of 1.5 m Caviar adhesive, laid on aquatic vegetation, usually on the upper parts of the stems. Absolute fecundity 115,0-120,0 thousand calves. Number spawn eggs at a time varies 13,0-44,6 thousand calves. The incubation period lasts 6-10 days, depending on water temperature.
At the age of 31 days at a body length of 12.2 mm larvae begin to feed actively diane small algae. Adults feed on the massive forms of zooplankton and benthic organisms – larvae of chironomids tipulid, small mollusks, olivine gohet, algae, fish eggs. In p. Kolyma aged 9 + years reaches a length of 30.2 cm, weight 518
Number and limiting factors. In Kolyma basin – commercial species, the maximum yield is reached 42.7 tons in 1981 following decades catch declined steadily due to organizational reasons and only amounted to 4.8 tons in 2004, especially a lot of carp in the lakes and tributaries of the left bank of the lower reaches of . Kolyma. In rivers CHAO experts estimate the number is quite high and is determined by natural causes. Limiting factors may act uncontrolled fishing, particularly detrimental during spawning, and anthropogenic pollution of water habitats carp.
Scientific and practical significance of species. Scientific interest for the development of geography and history of the problem of formation of the freshwater fish fauna of the North-East of Russia, as well as for understanding the adaptive capacity of species at high latitudes. Promising as an object of stocking lakes empty tundra zone of Chukotka to create commercial populations. In this regard, there is a lot of experience and positive results in Yakutia.