Estimation of key population parameters of Penaeus indicus H. Milne Edwards, 1837 (Crustacea: Penaeidae) in the Andharmanik River, southern Bangladesh: implications for sustainable management

Abstract

This study was conducted to estimate the key population parameters to understand both the current status and the yield of Penaeus indicus H. Milne Edwards, 1837 in the Andharmanik River, southern Bangladesh, using monthly samples collected from July 2019 to June 2020. We found that the size at first sexual maturity of P. indicus is 15.5 mm CL. The spawning season was August - December with a peak in September. Recruitment occurred at ~8.4 mm CL for an extended period of the year with two pulses: one in November (minor recruitment pulse) and another in February (major recruitment pulse). The von Bertalanffy growth equation gave the following results: CL_∞ = 31.9 mm and K = 1.14 year^-1. The overall growth performance index was 3.37 and the longevity was 2.6 years. The estimated total, natural, and fishing mortalities were 3.53, 2.15, and 1.38 year^-1, respectively. Therefore, the exploitation rate was 0.39 and the maximum sustainable yield was 0.42, indicating that the stock is almost optimally exploited. Hence our work should help improve decisions to (i) conserve the stock, (ii) maximize economic returns from the stock, and (iii) continue ensuring that the stock is exploited in an ecologically sustainable way.

Keywords:
Growth; mortality; recruitment; reproduction; yield