Distribution and size composition of the snowy sculpin Myoxocephalus brandtii (Cottidae) near the mainland coast of the northern Sea of Japan

Two groups of the snowy sculpinMyoxocephalus brandtiihave been identified off the mainland coast of the northern part of the Sea of Japan, separated by the area of pronounced dynamics of water masses near the 43th N parallel. Individuals of the southern group reach a length of 48 cm and those living to the north, 51 cm. From early spring to late fall, the snowy sculpin inhabits depths < 1 meter. In summer, it is found up to 100 m, concentrating mainly at 11–30 m. In autumn, it moves to shallow waters, where it begins spawning in late November at depths ~ 4–7 m. In winter, some males remain to guard clutches of eggs, while the remaining fish of the spawning part of the population move away from the upper part of the shelf, spreading to a depth of 141 m. Immature individuals throughout the year live mainly in the upper part of the shelf, which is most exposed to seasonal changes in temperature, as they are more eurythermal than adults. In summer, the snowy sculpin prefers temperatures of 8.1–18.0°C. Adults are found in waters warmed to no higher than 20°C and juveniles, up to 22.5°C.

snowy sculpinMyoxocephalus brandtii, distribution, density, depth, size, temperature, Sea of Japan