Maturation and spawning of Japanese spear lobster, Linuparus trigonus(Von Siebold) in Jeju Island

(Von Siebold) captured around Jeju island from January to September, 2008. Carapace length(CL),body weight(BW) and gonad weight(GW) were measured. Gonadosomatic index(GSI) and sex ratio werecalculated. In female group, CL showed the highest value in June and decreased after August. GW showed apeak in July and decreased rapidly after August. The mean gonadosomatic Index(GSI) reached a maximumvalue between June and August. Number of egg ranged from 143,360 to 189,504.Key words :