Bangladesh J. Fish. Res., 15-16, 2011-12: 115-124
Catch composition, seasonal abundance and length-weight relationship of elasmobranch species of the Bay of Bengal, Bangladesh Ehsanul Karim*, M. Zaher, Sumon Barua1, M.J. Rahman2 and M. Enamul Hoq3 Bangladesh Fisheries Research Institute, Marine Fisheries & Technology Station, Cox’s Bazar 4700, Bangladesh 1 Department of Fisheries, Marine Fisheries Wing, Chittagong 2 Present address: Department of Fisheries, Dhaka 3 Bangladesh Fisheries Research Institute, Mymensingh *Corresponding author. Email:
[email protected]
Abstract Present study consists of total catch, catch per unit effort, percentages and trends of catch composition, and length-weight relationship for elasmobranch species for the year of 2010 to 2013 of the Bay of Bengal, Bangladesh. A total of 26 elasmobranch species were identified from the landing data of artisanal fisheries, among them Carchariniformes was 14-18%, Rhinobatiformes was 4-7% and Mylobatiformes, Torpediniformes was 75-80%. Total catch percentage of true sharks varied from 14% to 18%, skates from 4% to 8% and rays from 73% to 80%. Among 26 identified species, length-weight regressions were presented for 24 species. The parameter b ranged from 2.71 for dog shark (Scoliodon laticaudus) to 3.50 for sharp nose guitar fish (Rhyncobatus granulatus) with a mean value of 3.138+0.02 and the median value ranged between 3.06 and 3.34. The coefficient of determination (r2) ranged from 0.890 for black spotted electric ray (Narcine teimlei) to 0.990 for dwarf sting ray (Himuntura walga). Sixteen species had r2 values between 0.95 and 0.98 while seven r2 values were less than 0.95. All regressions were highly significant (p3, negative if b
