Age, growth and maturation of the Sakhalin flounder Limanda sakhalinensis of the northern Sea of Okhotsk

Abstract

Abstract Sakhalin flounder abounds in the northern part of the Sea of Okhotsk and is currently a commercial fishing resource. Thus, the data needed for scientifically based management of this resource was obtained in the frame of a study carried out on the sampling of 1229 specimen caught in August–September of 2013 and 2019, determining age composition, growth and maturity of the fish. The otoliths were studied to reveal the age. The largest male with a credibly estimated age of 17 years was 27.0 cm TL and, weighted 184 g, while a 21 years old female was 35.0 cm TL and 408 g respectively. The measured data confirmed by the von Bertalanffy growth function calculations indicated that the growth of the female specimens is higher than that of the male. However, male specimens are faster in achieving their maximum length and reproductive maturity. Males start maturing at the age of 3 as they attain the length of 12.5 cm TL, while females mature at the age of five being 16.0 cm TL. The calculations indicate that for 50% of Sakhalin flounder, the males’ age of maturity is 4.1 years upon attaining TL 15.2 cm. Females mature in bulk at 7.5 years, attaining the length of 19.6 cm.