Some Biological Characteristics of Sardinella aurita in the Egyptian Mediterranean Water (Abu Qir Bay)

Elsira, Ibrahim; El-Far, Alaa; Younis, Alaa; Aly, Walid

doi:10.21608/ejabf.2025.420287

Some Biological Characteristics of Sardinella aurita in the Egyptian Mediterranean Water (Abu Qir Bay)

Authors

10.21608/ejabf.2025.420287

Abstract

This study investigated the growth, reproductive maturity, and condition of Sardinella aurita in Abu Qir Bay, Egyptian Mediterranean waters, based on 2,400 specimens collected over 12 months in 2023. Key findings included an average total length of 12.14cm (±1.85cm) and an average total weight of 15.23g (±7.52g). The length-weight relationships were robust with r² values of 0.956 for gutted weight and 0.946 for total weight, with the fitted equations W = 0.0070 × L^3.012 (gutted weight) and W = 0.0073 × L^3.030 (total weight) indicating an isometric growth pattern overall. However, when analyzed by sex, both males and females exhibited negative allometric growth with exponent values of 2.787 and 2.762, respectively, and no significant difference between them. The study also found that the average annual condition factor (K) was 0.727, with notable seasonal fluctuations, lowest values were recorded in July (0.622 for males and 0.654 for females) during the spawning period and a peak value of 0.787 was recorded for combined sexes in October during the post-spawning phase. Logistic regression analysis estimated the length at first sexual maturity (L_m₅₀) at 12.27cm, while the length at first capture (L_C) was determined to be 11.22cm. The gonado-somatic index (GSI) also revealed a bimodal spawning pattern with a major peak in May–June and a secondary peak in August–September. These findings underscore the vital role of biological monitoring in sustainable fisheries management while shedding light on the reproductive strategy of S. aurita in Abu Qir Bay. To protect spawning stocks during peak periods and support long-term sustainability, we recommend implementing seasonal fishing restrictions and establishing a minimum landing size to ensure individuals reach maturity before capture.

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