Gonad Development and Sex Ratio of Sharptooth Catfish (Clarias gariepinus Burchell, 1822) Cultured under Laboratory Conditions

摘要

In the present work, gonad development and sex ratio of sharptooth catfish (Clarias gariepinus) cultured under laboratory conditions over 365 days from hatching were investigated histologically and morphologically. The maturation stage for both males and females was detected 295 days after hatching. Five and 6 developmental stages were indicated for testis and ovaries, respectively. The developmental pattern of ovaries was categorised as the group-synchronous type. The sex ratio of the 200 sampled fish was 90:110 (male:female) and this difference was not significant (P > 0.05). Additionally, final live mean weight of the males was higher than that of the females (P < 0.05). The beginning of vitellogenesis was in April and ovarian development peaked in July. These results suggest that 1-year-old male and female C. gariepinus can be used as brood stock for seed production under standard laboratory conditions.