Abstract :
Forty-four specimens of the common torpedo (Torpedo torpedo) were collected from the discarded catch of long-line boat’s haul from Sidi Sha’ab harbor of Tripoli (May 2016) and used for establishing biodiversity and morphometric traits of the fish. The specimens ranged in size from 13.3 to 68.2 cm and in total weight from 92.61 to 989.25 g. The results revealed that the value of the constant b of the length-weight relationship was 1.9064 that indicated negative allometric growth (b< 3). The condition factors of Kf and Kc decreased progressively from 2.54 and 1.82 in the smallest fish size group (17.2 cm) to the largest one (67.5 cm) which recorded a rare value of (Kf = 0.32 and Kc = 0.25), respectively. The length-frequency distribution indicated that the youngest size-group (17.2 cm) peaked at a quarter of the studied samples. Biodiversity and Morphometric traits of the torpedo were related to total length as percentage ratios. Disk length and diameter were larger in females (48.6 and 43.0%) than in males (47.4 and 41.2%).
Keyword :
By-catch; Condition factor; Length frequently distribution; Length-weight relationship; Torpedo torpedo; Sidi Sha’ab of Tripoli