Abstract
Size at first maturity of Terapon jarbua was studied based on 114 male (14 to 28 cm in TL) and 140 female (14 to 32 cm in TL). The Logistic curves describing the relationship between the sexes and the proportion of 50% maturity (Lm50) were estimated at 20.8 cm in male and 21.8 cm in female of Terapon jarbua. The male reached 50% first sexual maturity at smaller lengths than female in this species. The gonads were classified into five maturity stages based on the size, colour and texture. Month wise predominance of different stage of maturity deferred during different months.