Growth, mortality, ovarian maturity, and exploitation of the Guinea shrimp, Holthuispenaeopsis atlantica (Balss, 1914) (Decapoda: Dendrobranchiata: Penaeidae) in inshore waters of Ghana, West Africa

Abstract

AbstractThe Guinea shrimp, Holthuispenaeopsis (= Parapenaeopsis) atlantica (Balss, 1914) is exploited by traditional and commercial fisheries in the Gulf of Guinea, West Africa. We assessed growth, mortality, ovarian maturity, and exploitation of the population of the species in inshore waters of Ghana as a contribution of filling the knowledge gap on the species. Samples were obtained from fish landing sites from three different coastal towns in Ghana from October, 2017 to May, 2018. Length-frequency data were used to estimate growth, mortality and exploitation ratio. The modal class for males was 6.0–6.9 cm total length (TL) and 9.0–9.9 cm TL in females. The length and weight relationship established that growth in both sexes was negatively allometric. The estimated growth parameters from the length frequency data fitted with the von Bertalanffy growth function were asymptotic length (L∞) of 10.08 cm for males and 15.4 cm for females. The growth constant (K) was calculated as 0.99 yr–1 for males and 0.89 yr–1 for females. The mean length-at-first capture (Lc) was found to be lower than the mean length at sexual maturity (Lm). The sex ratio showed a preponderance of females over males throughout the period, with 76.21% females. The total mortality rate (Z) for males was more than for females. The estimated natural mortality was 2.32 yr−1 for males and 1.93 yr−1 for females (M) whiles fishing mortality (F) rate was 1.22 yr−1 for males and 1.46 yr−1 for females. The exploitation ratio showed the stocks were not over-exploited. The estimated population parameters of the species obtained should be significant for the sustainable management of this resource.