Distribution and some traits of biology of Lycodes tanakae (Perciformes: Zoarcidae) in Primor'e waters (Sea of Japan)

With consideration of investigations made in 2004-2010, the spatial distribution of Lycodes tanakae, as well as some traits of its biology in Primor'e waters, is described. This species occurs all over the investigated region-from 42° to 49°N as explained by hydrological properties of bottom waters and by the bottom relief of this water area. In Promor'e waters, Lycodes tanakae occurs at depths of 87-1034 m. However, the majority of specimens (90%) prefers depths of 200-700 m. Thus, it can be attributed to the mesobathial ecological fish group. In spring and summer, juveniles of L. tanakae live at similar depths (200-350 m) where this species seems to spawn. In catches, L. tanakae is represented by specimens 11-90 cm in length, 0.1-4.9 kg in weight, and age from 1 to 10 years. The bulk of catches consists of specimens 40-70 cm long (62%), up to 2.2 kg in weight (90%), and of the age 4-7 years (72%). Sexual dimorphism in linear dimensions is not determined in L. tanakae. In summer, the ration of L. tanakae in Primor'e waters consists predominantly of cephalopods (on average, 59.4% of food weight). A noticeable part belongs to decapods (19.8%) and fish juveniles (16.6%). The smallest analyzed specimens consume small decapods and polychaetes. At the body length over 40 cm, L. tanakae pass over to predation. The value of the daily ration of Lycodes tanakae is, on average, 1.5% of the body weight. © 2011 Pleiades Publishing, Ltd.