Distribution and Some Features of Biology of Gilbert’s Irish Lord Hemilepidotus gilberti (Cottidae) in the Russian Waters of the Sea of Japan

Abstract

Main concentrations of Gilbert’s Irish lord Hemilepidotus gilberti in the Russian waters of the Sea of Japan are registered off the coasts of South and Central Primorye and western Sakhalin. During the course of the year, the representatives of the species are found at the depths between 9 and 668 m at a water temperature of the near-bottom layer from –1.8 to +16.1°С. In the summer, they prefer the upper and middle zones of the shelf with a temperature between 1.5 and 3.0°С, while the fishes are found in the lower part of the shelf and upper zone of the continental slope with low positive temperatures in the winter. The juveniles live at smaller depths than adult individuals and at the largest seasonal temperature fluctuations. The fishes 3–37 cm in body length are registered in the catches, and the size group 18–26 cm prevails. The females are more abundant in the population, and they reach a larger body size than the males. Mass spawning occurs in August and September at the depth of 30–80 m. In the waters of Primorye, Gilbert’s Irish lord feeds on mainly decapods, polychaetes, and amphipods. From April to November, the daily ration of the juveniles and adult fishes is equal to 5.0 and 3.0% of body weight, respectively. Two maximums are observed in the feeding intensity of adult fishes: prespawning (July) and postspawning (November). The biomass of Gilbert’s Irish lord in the Russian waters of the Sea of Japan is estimated as 1500 t.