Assessment length-weight relationship, sex ratio and condition factor of Large Head Hairtail (Trichiurus lepturus) in Gulf of Oman (Sistan and baluchestan province)

Length-weight relationship, sex ratio and condition factor of Trichiurus lepturus were conducted from September 2014 to August 2015 from different landing sites along the Sistan & Baluchistan province coastline – Oman Sea. A total of 283 specimens were randomly collected during study period. The monthly collections were sexed and size grouped (8 size groups with 10 mm class intervals). Among the studied species, 42% were male and 56% were female and the overall sex ratio was female biased (1.37:1).  The maximum and minimum total length were 115 cm and 49 cm, respectively. The maximum and minimum total weight for this species was 1000 g and 180 g. respectively. Samples were found to be ranged from 49 to 115 mm in total length and the total weights were found to be ranged from 180 to 1000 g.  In the present study, the length-weight relationship for total population was calculated as W=0.048TL2.67, R2 = (0.919). The length-weight relationship was calculated as W = 0.066 TL 2.410, R2 = (0.945) for males and W = 0.0087TL 2.301, R2 = (0.925) for females. t-test analysis showed a significant difference between the b values obtained for Female, male and total population from number 3 which show a negative allometric growth. The maximum condition factor (K) of 1.25 was recorded during the study period. The condition factor declined from March to mid-August, and then gradually increased, reaching its maximum level in the fall.