Biological aspects and exploitation of Plectorhinchus gaterinus (Forsskal, 1839) (F: Haemulidae) from the northern Red Sea, El-Tor, Egypt

M. Amin, Amal; A. El-Ganainy, Azza; M. Sabrah, Manal

doi:10.21608/ejabf.2019.67371

Biological aspects and exploitation of Plectorhinchus gaterinus (Forsskal, 1839) (F: Haemulidae) from the northern Red Sea, El-Tor, Egypt

Document Type : Original Article

Authors

10.21608/ejabf.2019.67371

Abstract

This investigation is considered to be the first analysis involving the most useful parameters for the management purposes of Plectorhinchus gaterinus from El-Tor, Egyptian northern Red Sea coast. Age was estimated by using two methods, the fish otolith reading and the length-frequency analysis (LF) of 248 samples collected through the fishing season 2015/2016. The length-weight relationship was determined for all samples, that ranged from 11.0 to 39.0 cm. The "b" value exhibits an isometric growth pattern (b ≈ 3.0). Eight age groups were recorded by the two methods. Growth parameters were estimated by applying the plager method's, 1983 where the asymptotic length (L_∞) and the growth rate (K) were computed as 41.02 cm and 0.28 year^-1 respectively from the otolith reading, while that resulted from (LF) analysis were 43.78 cm and 0.21 year^-1respectively. The total mortality rate (Z) was 0.66/Y, natural mortality (M) was 0. 34/Y then the fishing mortality (F) was 0.32/Y. Length at first sexual maturity was estimated to be in the length group of 23.0-23.9 cm for males while it was in the range of 25.0-25.9 cm in females. The results indicated that the current fishery status of Plectorhinchus gaterinusfrom El- Tor, Egyptian Red Sea is in the optimum exploitation rate (E = 0.48) and any additional fishing effort will cause an over-exploitation and destroy the fish stock.

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