Age Composition, Growth and Mortality of Spotted Weever (Trachinus araneus- Cuvier, 1829) and Greater Weever (Trachinus draco- Linnaeus, 1758) from the Western Egyptian Mediterranean Sea

Heneish Et Al., Rasha Ali

doi:10.21608/ejabf.2022.256118

Age Composition, Growth and Mortality of Spotted Weever (Trachinus araneus- Cuvier, 1829) and Greater Weever (Trachinus draco- Linnaeus, 1758) from the Western Egyptian Mediterranean Sea

Document Type : Original Article

Author

Rasha Ali Heneish et al.

10.21608/ejabf.2022.256118

Abstract

The present study addressed the age composition, growth, and mortality of spotted weever Trachinus araneus (Cuvier, 1829) and the greater weever Trachinus draco (Linnaeus, 1758). A total number of 536 T. araneus and 460 T. draco samples were collected from the Western Egyptian Mediterranean Sea using the bottom trawl during the period from August 2018 to August 2019. Total lengths ranged from 10.9-30.0 cm and from 11.8 to 27.6 cm for T. araneus and T. draco, respectively. The calculated length-weight relationship showed a negative allometric growth pattern for the two species (males, females and total samples). In the present study, T. araneus reached six years, while T. draco had only five years. The von Bertalanffy Growth parameters for the total samples were L_∞ = 32.55 cm, W_∞ = 210.6 g, k = 0.41 y^-1, t_o = -2.55 y for T. araneus, and L_∞ = 27.3 cm, and W_∞ = 147.16 g, k = 0.5 y^-1, t_o = -3.29 y for T. draco. The growth performance index (Ф) was 2.64 and 2.727 for T. araneus and T. draco, respectively. Total, natural, and fishing mortality rates were 0.803, 0.761, 0.042 for T. araneus and 0.931, 0.835, 0.096 for T. draco. For the exploitation rate, E = 0.052 and 0.103 for T. araneus andfor T. draco, respectively, which indicates that the stock of

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