Length-weight relationship and condition factor of Sphyraena putnamae Jordan and Seale, 1905 and Sphyraena obtusata Cuvier, 1829 from Pamban Island waters, Gulf of Mannar, south-east coast of India

Abstract

Length-weight relationships (LWRs), Fulton’s condition factor (K) and relative condition factor (Kn) of two barracuda species, Sphyraena putnamae Jordan & Seale, 1905 and Sphyraena obtusata Cuvier, 1829 were studied from the Gulf of Mannar. The length and weight range for S. putnamae was 23.6 to 55.3 cm and 70.89 to 702.50 g, respectively, whereas for S. obtusata it was 17.7 to 40.9 cm and 34.68 to 299.01 g, respectively. The estimated ‘b’ value for S. putnamae ranged from 2.632 to 2.743, whereas for S. obtusata it ranged from 2.621 to 2.722. The results indicated a negative allometric growth pattern (b<3) both the species. For S. putnamae, the coefficient of determination (r2) was from 0.928 to 0.969, whereas for S. obtusata, it was 0.904 to 0.930. The regression slopes (b) of both sexes of S. putnamae and S. obtusata showed no significant difference (p>0.05) in the analysis of covariance (ANCOVA). Condition factor (K) was estimated to be higher for S. obtusata (0.70±0.10; Mean±SE) than S. putnamae (0.49±0.04) for the total population. The relative condition factor (Kn) was estimated as 1.05±0.07 for S. putnamae and 1.00±0.12 for S. obtusata populations.

Keywords: Allometric growth, Biomass, Fishery management, Morphology, Sphyraenidae