Length- weight relationship, condition factor and age of kawakawa (Euthynnus affinis), in the eastern Mediterranean coast, North Sinai, Egypt.

Abstract

Monthly length composition data (Total length) of kawakawa (Euthynnus affinis), which landed between January and December 2020 in the Coastal Waters of the Mediterranean coast of North Sinai Egypt were used to estimate the length-weight relationship, condition factor, age and growth. The computed length-weight relationship (W = 0.0186 L 2.8595 ) showed a negative allometric growth pattern. The average condition factor was 1.12 and the relative condition factor was 1.01. The age was determined indirectly by the analysis of length frequency data using the standard statistical method of Bhattacharya involved in the FiSAT II . Five age stages were found, and the length at the end of each age was 22.62, 37.56, 52.28, 59.21, 62.85 for years 1, 2, 3, 4, and 5, respectively.The growth parameters of the von Bertalanffy equation were estimated as L∞=87.67.2 cm, K= 0.24 per year and tо = -0.56 per year.The study recommended not to catch small fish less than 48 cm

Estimating relative abundance of kawakawa (Euthynnus affinis Cantor, 1849) landed in eastern indian ocean using catch and effort data

“…In this study, the size distribution of kawakawa ranged from 16 to 77 cm FL. The result aligned with the previous studies in the Western Sumatera, Java Sea, Persian Gulf, Sea of Oman, and eastern Mediterranean coast [6,14,16,18]. Most of the lengths of kawakawa landed in the Eastern Indian Ocean in the present study were above the length at first maturity (>38 cm FL).…”

“…The time series biological data of certain species is critical to obtaining the goal of fisheries science, specifically to manage the fish stock [15]. One of the key parameters is fish length, which is applied to determine the maturity and fish age [1,16,17]. In this study, the size distribution of kawakawa ranged from 16 to 77 cm FL.…”