Maturity and Spawning of Snailfish, Liparis ochotensis (Schmidt), in the East Sea

Maturity and spawning of the snailfish, Liparis ochotensis was investigated based on samples collected by gill net in the East Sea of Korea from December 2008 to December 2009. The average total length of L. ochotensis was 63.4 cm and 64.1 cm for females and males, respectively. Gonadosomatic index (GSI) began to increase in July, reaching a maximum in November, then began to decrease in December. Monthly changes in the GSI values of L. ochotensis were similar for females and males. Annual reproductive cycle of this species can be divided into five successive stages in females: early growing stage (May), late growing stage (June to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Males show four successive stages; growing stage (May to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Relationship between total length (TL) and fecundity (F) was F=$0.00003TL^{4.002}$ ($R^2$ = 0.703), and F increased with TL. Total length at 50% group maturity was estimated to be 55.8 cm. Our findings suggest that the spawning period takes place from September to December, with the main spawning period occurring from October to December.