Life history traits of ribbonfish Trichiurus lepturus (Linnaeus, 1758) in the Persian Gulf and Oman Sea

Ribbonfish, Trichiurus lepturus (Linnaeus, 1758), is an important component of subsistence fisheries throughout its tropical and subtropical distribution. The catch rate of ribbonfish has increased seven-fold in a decade in the Persian Gulf and Oman Sea. We collected monthly biological samples from T. lepturus, to estimate growth and mortality parameters, and identify species reproductive patterns. The annual instantaneous rate of fishing mortality (0.63 year-1) was higher than the target (Fopt= 0.26 year−1) and limit (Flim= 0.35 year−1) reference points, indicating that the ribbonfish stock is overexploited. The gonado-somatic index and monthly gonadal maturity stages of harvested fishes indicated that T. lepturus presents continuous reproductive activity throughout the year, peaking in the four months from March to June. The size at first maturity was estimated at 66.9 cm total length for females. The overall sex ratio differed significantly from the expected 0.5 with a larger proportion of females (χ2 = 203.10; p < 0.001).  The current study provide important information that can facilitate management, conservation, and sustainable fishing of T. lepturus in the Persain Gulf.