The size and weight composition and the some data of the otolith shape analysis of underyearlings and two-year-old individuals of saffron cod Eleginus gracilis in the south-western part of the Bering Sea

Abstract

It is demonstrated that the body length and weight of 0+ age saffron cod varied in the trawl survey catches in Karaginsky Gulf in October of 2013 in the ranges 5.3-16.8 cm and 0.5-30.5 g. The number of males and females was equal. Female and male average length and weight did not differ. The correlation between the length and weight of 0+ age saffron cod can be approximated through the y=0.0029x3,3077 power function curve. The weight growth rate in the underyearlings with the body length up to 10 cm and the body weight up to 5 mg is lower that in the bigger individuals. The otolith length in the underyearlings varied in the ranges 3.2-8.1 mm, the width - in the ranges 1.3-3.9 mm, and the weight - 3-32 mg. Tight positive correlation exists between the body length and weight of the fish and the otolith length, width and weight. The body length of 1+ age saffron cod in Karaginsky Gulf varies in the ranges 12.9-29.0 cm, and the weight - 13-190 g. The correlation between the body length and weight of 1+ age saffron cod is reflected in the function y= 0.0025x3.3496. Females are bigger than males. The differences between their selective means, compared via Student’s test, are statistically significant. The difference in the growth rates of males and females of saffron cod in Karaginsky Gulf during their second year of life can occur due to mass gonad maturation in this age. The otolith length of two-year-old saffron cod can vary in the ranges 7.0-9.4 mm; the width - 2.7-7.4 mm, and the weight - 19-48 mg.