About biology of saffron cod Eleginus gracilis inhabiting the Avachinskaya Bay (Southeastern Kamchatka)
Biological cycle and some other important life traits of saffron cod are characterized in this paper basing on the samples, collected from net, sweep-net and rod catches in the Avachinskaya Bay in 2004-2012. It has been established, that saffron cod inhabits the bay all year round. Body length and age of the caught fish varied and ranged from 11 to 43 cm and 0+ - 4+ years. Spring and summer catches mainly consist of juveniles of age 0+, 1 or 1+, which prefer to feed in shallow waters unlike elder individuals feeding in deep waters of the Avachinsky Gulf. More than 50% of autumn and winter catches were fish with the body length 21-43 cm of age 1+(2) or 2+(3), migrating from the gulf back to the bay for spawning and wintering. The fish with the gonads at the V-th stage of maturation were observed in January-February catches in the Krasheninnikova and Rakovaya Bays and in the Avacha River estuary, that provides evidence of spawning of saffron cod in these water basins during the winter period. Both first and common maturation of saffron cod of the Avachinskaya Bay occurs at the second year of its life cycle. At first maturity males' length is 19 cm, females' - 21 cm. Most of males become mature at length of 20 cm, and females - 23 cm.