Comparative Characteristics of the Size Parameters of the Threaded Sculpin Gymnocanthus pistilliger (Cottidae) in Peter the Great Bay (Sea of Japan) and off the Western Coast of Kamchatka (Sea of Okhotsk)

Abstract—

It is shown that in Peter the Great Bay, the southern part of the range of the threaded sculpin Gymnocanthus pistilliger, its maximum size is larger than in the more northern waters off western Kamchatka. Reliable records of the species in trawl catches begin when individuals reach an absolute body length of 20 cm. Since males reach smaller sizes than females, their records, especially in the north, are less comprehensive. The growth rates of fish in Peter the Great Bay are higher, which is why the fish of the same age are larger here than in the waters off the Kamchatka Peninsula. The weight of individuals of the same size in the bay is also larger. The best growth rates in the area located to the south is determined by more favorable conditions of the aquatic environment. Despite the differences in growth rates, the maximum age of fish reached in populations is similar. The sex ratio with a predominance of females is also similar.