Round whitefish (Prosopium cylindraceum)
This interesting representative of the whitefishes subfamily belongs to separate genus that has American origin. These fish are widespread in North America, home to six species of round whitefishes. Round whitefishes had entered Asia through the Bering Land Bridge – a strip of land that had existed during the glaciation periods on the site of the Bering Strait and connected Chukotka with Alaska. Currently, the round whitefish inhabits all of the Eastern and Central Siberia, including the Yenisei basin.
The spawning of the round whitefish, same as of most whitefishes, occurs in the fall – at the end of September or in October. This fish feeds mainly on benthic invertebrates; sometimes the round whitefish consumes small fish, such as sculpins, and fish eggs.
The round whitefish is widespread in the northern part of the Far East: it is found in the basins of the Kolyma, Anadyr, Amguema, Penzhina, Paren and Okhota Rivers. This fish is also present in Chukotka and in the rivers to the north from Kamchatka (Koryak Upland). This fish can also live in some cold lakes (Ilirney, Nyarka, and Labynkyr).
The maximum age of the round whitefish is from 10 to 15 years. Some specimens can reach the length of 52 cm and a weight of 2.2 kg (Khantaiskoe Reservoir). The fish from 20 to 40 cm in length predominate in the catches. The round whitefish populates the foothill sections of the rivers with stony and sandy-pebble bottom.