Abstract
The present study describes the first complete and comprehensive description on life-history traits of Sardinella melanura including length-frequency distributions (LFDs), length-weight relationships (LWRs), condition factors (allometric condition, K-A; Fulton's condition, K-F; relative condition, K-R), and relative weight (W-R) in the Gwadar, Balochistan Coast, Pakistan. Additionally, form factor (a(3.0)) using available a and b regression parameters of LWRs and size at first sexual maturity (L-m) using available maximum length for 07 Sardinella spp. in 23 water-bodies were calculated. Seasonal samples of S. melanura were collected from the Gwadar, Balochistan Coast, Pakistan using gill nets during July 2013 to June 2014. Total length (TL) was measured to nearest 0.1 cm using digital slide calipers and total body weight (BW) was measured using an electronic balance with 0.1 g accuracy for each individual. A total of 600 individuals of S. melanura were analyzed, where minimum and maximum TL was 12.5 cm and 23.00 cm, respectively and BW was 16.5 g and 114.8 g, correspondingly. Highest number (25.83%) of its population stands at 17.00 cm to 18.00 cm size group. The b value of LWR indicated negative allometric growth in the population. All the condition factors (K-A, K-F, K-R, and W-R) were significantly correlated with TL and BW (P < 0.001). W-R showed significant difference from 100 (P < 0.001) representing imbalanced population in presence of prey and predator. In addition, the a(3.0) for S. melanura was 0.0078. The size at first sexual maturity (L-m) was 14.43 cm in TL of S. melanura in the Gwadar, Balochistan coast, Pakistan.