Reproductive biology of common silver biddy Gerres oyena in Okinawa Island of southern Japan
Version of Record online: 31 MAR 2008
© 2008 Japanese Society of Fisheries Science
Volume 74, Issue 2, pages 265–275, April 2008
How to Cite
KANAK, M. K. and TACHIHARA, K. (2008), Reproductive biology of common silver biddy Gerres oyena in Okinawa Island of southern Japan. Fisheries Science, 74: 265–275. doi: 10.1111/j.1444-2906.2008.01521.x
- Issue online: 31 MAR 2008
- Version of Record online: 31 MAR 2008
- Received 25 January 2007. Accepted 5 October 2007.
- Gerres oyena;
- Okinawa Island;
- spawning season
ABSTRACT: Common silver biddy Gerres oyena were collected monthly between November 2002 and November 2005 in Okinawa Island of southern Japan. The seasonal reproductive cycle of this species was investigated using the gonadosomatic index (GSI) and through histological observation of gonads. Temporal variation in the GSI reflected gonadal development from histological observations; ovary development occurred from March to September and testes development occurred between March and August. Maximal development was observed in April and May in both sexes. While mean values for hepatosomatic and lipidosomatic indices decreased markedly in females relative to males during gonadal development, mean condition factors decreased with gonadal recrudescence in both sexes. The minimum standard length (SL) at sexual maturity was 89.7 mm for females and 81.4 mm for males and the size at which 50% of individuals were sexually mature was 104 and 92 mm SL in females and males, respectively. The power relationships of batch fecundity (BF) versus standard length (SL, mm) and body weight (BW, g) of females can be expressed as BF = 46.7 × e1.64SL and BF = 19 697 × e0.49BW, respectively.