Population Parameters of Spadenose Shark, Scoliodon laticaudus in the Bay of Bengal, Bangladesh

Abstract

Population parameters of Spadenose shark, Scoliodon laticaudus in the Bay of Bengal were estimated in the coastal waters of Bay of Bengal. Total 829 Specimen were sampled at five different landing sites from the southern part of the country between March 2017 and February 2018. The study provides information on length weight relationship, growth parameters (growth coefficient, asymptotic length), mortality and recruitment based on monthly length-frequency data using FiSAT II software. The derived length weight relationship was W = 0.1893L¹•⁴⁵⁷⁴ which revealed negative allometric growth. The study estimated Growth parameters: K= 0.5 year⁻¹ and L∞= 75.6 cm, Mortality: Z= 1.97 year⁻¹, M= 0.78 year⁻¹ F=1.18 year⁻¹, Length at recruitment; 46.30 cm, and Exploitation ration: 0.60. The exploitation ratio indicates overfishing. Immediate action should be taken to reduce the exploitation. Recruitment pattern showed continuous recruitment with two major peaks per year; one peak in March and other in September. The results obtained from this study would be utilized to manage the unregulated and undersized (<46.30 cm) catches of Spadenose shark population in the Bay of Bengal, Bangladesh.