امین اوجی فرد

Assesment of some biological aspects including sex ratio, the relationship between fork length-weight and feeding habits of the fish Nemipterus japonicus (Bloch, 1791), were studied from September 2012 to February 2013 by regular monthly collections in coastal waters of Persian Gulf (Bushehr Province). A total of 285 specimens, including 101 males and 184 females were collected. Results indicated that, sex ratio was 1:1.83 (male to female). Chi sqare test was applied to compare male and femal frequency, and show did a significant difference (p>0/01, df=1, X2 =24.17). Females showed a higher frequency than males in samples (64.56%). The size range for male was 16.8 to 27 cm and weight 100 to 380 gr and for female, 17 to 26.5 cm and weight 98 to 303 gr. The Mean fork length for males was 23.38±0.54 and for females was 21.01±0.23 cm. Average total weight of males and females were 242.21±15.32 and 172.06±5.61 gr, respectively.The relationship between length and fish weight for males was: W=0.025FL2.89, R2=0.95 and for female was : W=0.052FL2.65, R2=0.85 respectively. The gut content consisted mostly of fish species and the relative length of gut (RLG) was 0.87, on average. Among the total studied fishes,122 fishes had empty and 193 full stomachs. On the basis of the food composition in full stomachs, crab, fish, shrimp, polychaete, octopus and lobster were abundant groups. The main food items in this species were crustaceans(38.84) and fishes (13.98).