Fig. 2

Changes in the gonadosomatic index (GSI) during the oocyte development stages in Coilia nasus. The stages were defined as: onset stage (stage I; fish collected in March), developmental stage (stage II; April), multiplication stage (stage III; May), mature stage (stage IV; June), spawning stage (stage V; late June), spawned stage (stage VI; July), and rest stage (stage VII; August). Data are expressed as the mean ± SE (n = 7 for each stage). Columns with different letters above them are significantly different (P < 0.05, a<b<c <d)