Population structure of banana shrimp, Penaeus merguiensis De Man, 1888 in Strait of Hormoz, Persian Gulf

Abstract

Monthly length frequency data of banana shrimp, Penaeus merguiensis were collected from the coastal waters of North east Persian Gulf, from January 2012 to January 2013. Software package FiSAT was used to analyze the length frequency data. Growth parameters, mortalities, exploitation rate and recruitment pattern were estimated from the carapace length in the area. Based on length – weight relationship, the estimated parameters, a was 0.0015 for male and female and b was 2.8015 for male and 2.7852 for female. The estimated growth parameters: L∞=39.5 mm, K= 1.8 year−1 and t0=-0.08 year−1 for males and L∞ = 50 mm, K= 1.5 year−1 and t0=-0.09 year−1 for females. Longevity was estimated 1.67 and 2.00 years for male and female respectively. The estimated mortality coefficients, were Z=5.9 (4.89 – 6.92) year−1 (α=0.05), M=2.9 year−1 and F=3.0 year−1 for male and Z=5.7 (4.94 – 6.37) year−1 (α=0.05), M=2.5 year−1 and F=3.2 year−1 for female. The length at first capture, Lc estimated from the probability of capture routine was 23.3 mm for male and 24.2 mm for female. Sex ratio (M:F=1.1:1) was significantly different to 1:1. The exploitation rates of shrimp were 0.49 and 0.56 for male and female respectively which could get higher value because survival of spawning stock after fishing season related to environment factors have less effect on next year biomass. Recruitment was continued throughout the year but with one major peak in July to November.