Age, growth, mortality and yield per recruit of the humpnose big-eye bream Monotaxis grandoculis (Forsskål, 1775) from Hurghada, Red Sea, Egypt

El-Mahdy Et Al., Samia M.

doi:10.21608/ejabf.2022.247479

Age, growth, mortality and yield per recruit of the humpnose big-eye bream Monotaxis grandoculis (Forsskål, 1775) from Hurghada, Red Sea, Egypt

Document Type : Original Article

Author

Samia M. El-Mahdy et al.

10.21608/ejabf.2022.247479

Abstract

The humpnose big-eye bream, Monotaxis grandoculis is one of the economically important lethrinid species inhabiting the Egyptian Red Sea and has never been studied before in this area. The objective of this study is to estimate the age and growth parameters, mortality, and yield per recruit of M. grandoculis to assess its status and give the basic parameters required for its rational exploitation. A total of 438 specimens (135 male and 303 female) were collected monthly from January to December 2020 from the Hurghada landing site, Red Sea, Egypt. Based on otoliths readings, the maximum age recorded for this species was eight years for both sexes. The length-weight equation constants were a = 0.009, b = 3.197 for males; a = 0.0077, b = 3.238 for females and a = 0.0078, b = 3.237 for sexes combined. Based on the von Bertalanffy growth parameters and mortality rates, the exploitation rate (E) was found to be around the optimum one (0.47, 0.50, and 0.47 for males, females, and sexes combined, respectively). From the management point of view, the current E was higher than the E_0.5 that conserves the spawning stock biomass, and to achieve the rational exploitation of this species, the present level of fishing effort should be reduced through appropriate fishing regulation techniques.

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