Some biological aspects and fisheries assessment of Diplodus vulgaris (Geoffrey Saint-Hilaire, 1817) (Teleostei: Sparidae) caught by gillnets (Egyptian Mediterranean waters, Alexandria)

This study was conducted to estimate some biological aspects and fisheries assessment of Diplodus vulgaris caught by gillnets during the period 2018–2020 from the Egyptian Mediterranean waters of Alexandria. From an overall of 1004 individuals of D. vulgaris (10.0 – 24.0 cm TL) examined, lengths from 13.0 to 17.0 cm were representing 82.67% of the total fish number. The length-weight relationships for total and gutted weights of the D. vulgaris were: Log W = −1.7144 + 2.9063 Log L (R2 = 0.9982) and Log W = −1.8508 + 2.9903 Log L (R2 = 0.9967), respectively. The condition factor (k) was found to be fluctuating between 1.268 and 1.534 with an average value of 1.395 ± 0.0597. The overall sex ratio (M: F) was 1.00: 0.63 and the chi-square test revealed highly significant difference (χ2 = 24.80; df = 1; P