reproductive biology of Vermiculated Sailfin Catfish        

Study on reproductive biology of Vermiculated Sailfin Catfish Pterygoplichthys disjunctivus (Weber 1991) in the Mekong Delta, South of Vietnam was carried out from April, 2013 to March, 2014. The results showed that the matured fish in stage IV and stage V was found in all year round, in which the highest ratio of maturation was determined in the period of April-September. Gonadosomatic Indexs (GSI) of males were lower than those of females, and GSI of female was high in the period of April-September and the highest value in June (7.98 %). Meanwhile, Hepatosomatic Index (HSI) was changed inversely with GSI and ranged from 0.78 to 1.47 %. The condition factor (CF) ranged from 3.08 % to 7.2 % and showed that CF was also higher from April to September. The results indicated that the main spawning season of P. disjunctivus occurred from April to September; however this species in the Mekong Delta can breed in all year round. The fecundity of P. disjunctivus ranged 252 to 5820 eggs/female and relative fecundity fluctuated from 2665 to 18092 eggs/kg of female. Length at first maturity (L_m) of female and male was 11.12cm and 9.14cm, respectively.