BIOLOGICAL INVESTIGATION OF TIGER-TOOTHED CROAKER, OTOLITHES RUBER, IN OMAN SEA ALONG SISTAN AND BALUCHISTAN PROVINCE

During the years 2003-2004, biological aspects of Tiger-toothed Croaker, Otolithes ruber, was investigated in Oman Sea along Sistan and Baluchistan Province. Based on the frequency of developed maturity stages (IV,V), a prolonged spawning activity extending from August to March was determined for 0. ruber. The Gonadosomatic Index (GSI) suggests two peaks which a minor one in October and a major one in March-April. Comparison of Hepatosomatic Index (HI) and Condition Factor (Kn) with the spawning peak indicated a reverse relationship. According to length at first maturity (Lm50%=40cm) data and exploitation of fish at lengths more than 40cm, the stretched optimum mesh size of nets was calculated at 100mm. Analysis of stomach food items, showed that fish group dominated the diet (80%), of which Anchovy accounted for 40% of the total frequency. We estimated the exploitation rate of the fish at E= 0.6. The length infinity (L¥), natural mortality (M), fishing mortality (F), total mortality (Z) and Growth Coefficient per year (K) were calculated at 68.6, 0.69, 1.05, 1.74 & 0.35 respectively. The relationship between length and weight of the fish in the province was also determined. The parameters a, b and r (correlation coefficient) of the relationship were 0.0085, 3.0435 and 0.98 respectively.