Fishery, biology and population characteristics of longtail tuna, Thunnus tonggol (Bleeker, 1851) caught along the Indian coast

Length-weight relationship, morphometric and meristic characters of Johnieops sina (Cuvier, 1830) from Ratnagiri waterswere studied by examination of 874 (454 male and 420 female) specimens collected during December 2009 - November2011. The male fishes ranged from 100 to 195 mm in length and 8.2 to 80.1g in weight and females ranged from 105 to232 mm in length and 9.4 to 128.2 g in weight . The length-weight relationship was established as W= 0.000006092 L3.13429563 for male, W=0 .000005234 L 3.169965 for female and W= 0.000005029 L 3.175118 for pooled, indicating positive allometricrelationships. The deviations in the growth rate in present study from that of earlier findings may be result of the influenceof the difference in environmental conditions in other geographical areas, apart from difference in the stocks. Correlationcoefficient (r) was highest for standard length and total length (0.9841) and lowest for eye diameter and head length (0.7527).Based on the findings of the present investigation on meristic characters, the fin formula can be written as B7, D 9-11/1/26-31,P 16-18, V 1/5, A 2/7-8, and C 17-18.. Number of gill rakers on the first left gill arch ranged from 13 to 15.