Biometry, length-weight and length-length relationships of flathead sillago Sillaginopsis panijus (Hamilton, 1822) (Perciformes: Sillaginidae) from the north-western Bay of Bengal

Biometry, length-weight relationships (LWRs) and length-length relationships (LLRs) of Sillaginopsis panijus (Hamilton, 1822) were investigated in the Indian coast of north-western Bay of Bengal. Altogether 622 specimens were collected between August 2018 and September 2019 from landings by trawls (30-35 mm mesh size), gillnets (15-55 mm mesh size) and shore seines (7-15 mm bag mesh size). The total length and weight of the specimens ranged from 7.8-40.3 cm and 2.9-506 g, respectively. The LWR established was W=0.0048 L-3.059 for males, W=0.0032 L-3.185 for females and W=0.0047 L-3.0645 for indeterminates, indicating positive allometric growth pattern. All the LWRs were highly significant (p<0.001, r(2)>= 0.977). The highest coefficient of correlation (r) was observed for total length against fork length (0.999) and lowest for head length against eye diameter (0.951). The fin formula was expressed as D-1 X, D-2 I + 24-28, P 17-22, V I + 5, A II + 25-27, GR 2-3/6-9. The study provides the first detailed account of the biometric relationships of S. panijus in the north-western Bay of Bengal, which can be used as baseline information for subsequent biological and population based studies in the region.