The Summer Distribution of Sculpin Fish (Cottidae) on the Continental Margin of the Sea of Japan from Cape Povorotny to Cape Mapatsa

Abstract

We identified Gymnocanthus detrisus as the absolute dominant species in the taxocene of sculpins (family Cottidae), caught below 20 m water depth in the aquatic area between Cape Povorotny and Cape Mapatsa. Myoxocephalus polyacanthocephalus, Gymnocanthus herzensteini, Enophrys diceraus and Triglops pingelii are dominant as well. Subdominant species are Triglops septicus, Icelus cataphractus, Hemilepidotus gilberti, Myoxocephalus brandtii, Myoxocephalus jaok, Taurocottus bergii and Gymnocanthus pistilliger. Other types of fishes identified in this area are insignificant in abundance. Sculpins aggregate at greater depth in the southern aquatic areas, from Cape Povorotny to Olga Bay, and from Olga Bay to Cape Belkin, than in the northern areas, between Cape Belkin and Cape Zolotoy, particularly between Cape Zolotoi and Cape Mapatsa. We attribute this phenomenon to the differences in water regimes. The highest densities of sculpins are generally typical for the southern area. Conversely the lowest densities are typical in the northern area. However, some species prefer northern areas. The minimum depths habitat for different species varying from less than 20 m to 82 m; the maximum depths range from 80 to 530 m. Due to the high species diversity, aggregations of sculpins are observed in a wide bathymetric range from 20 to 300 m, with peak values at depths of 150–200 m. Sculpins live in summer at water temperatures above 0.4°C. The shallow water species of sculpins tolerate much greater temperature ranges then deep water species. Hence, the stenotherm increases in deep water species.