Reproductive biology of Indian squid, Uroteuthis duvauceli (Orbigny, 1835), in the northern Gulf of Oman

Some aspects of the reproductive biology of the Indian squid, Uroteuthis duvauceli, were studied from June 2006 to May 2007. A total of 1200 specimens were collected from approximately 30-80m depths by trawling in 50 stations, of which 360 samples were studied for sex determination and fecundity. The minimum and maximum total and mantle length, and body weight were recorded in December and June, respectively. The highest range of total length (410-420mm), mantle length (150-160mm and body weight (90-100g) were encountered in September. The specimens were composed of 34% male and 66% female (M:F=1:2). This species was found to be more abundant in summer. The minimum and maximum ovary weighs were 2.1g and 7.9g with an average of 4.9g, respectively. These values for nidamental gland weight were 0.70 and 2.61g with an average of 1.6g. The minimum and maximum absolute fecundity were 25510 (in August) and 375600 (in April), respectively. These values for relative fecundity were 5207 (in April) and 867 (in August), respectively. The highest gonadosomatic index (GSI) was in April (14.38) and the lowest was in July (8.63). This squid is, therefore, assumed to be a spring spawner. Minimum and maximum egg diameter were 0.72mm (in August) and 2.5mm (in April), respectively.