Population dynamics and stock assessment of hermaphrodite prawn Exhippolysmata ensirostris. Kemp, at Nawabunder, Gujarat

Abstract

Exhippolysmata ensirostris fonned 27% of the non-penaeid prawn landings at Nawabunder, a major dol net centre in Saurashtra. The peak landing period is from October-December with an annual landing of 302,2 t during the period 1983-86. The growth parameters are Lα 105.84 mm, t, = —0.09 month and K = 0.193 on monthly basis. The total mortality coefficient, ‘Z' for the three year period varied from 8.39 to 11.35. The natural mortality] coefficient, is 3.2. The MSY, calculated from the yield per recruit analysis is 334.6 t which is close to the present yield and the exploitation rate is 0.69. In spite of hiigh exploitation rate, the fishery has sustained as the exploited stock consists of large size adults with size at capture (Ic = 73.0 mm) which is much higher than the size at 50% maturity (Lt»i 50 = 58 mm).