Age and Growth of the Blackspot Snapper Lutjanus ehrenbergii (Family: Lutjanidae), from the Red Sea and the Arabian Gulf

The present study is an integral part of our ongoing investigation on the snapper fish (Family: Lutjanidae) and their distribution between the Red Sea, Egypt, and the Arabian Gulf, Qatar. In 2022, the blackspot snapper Lutjanus ehrenbergii was collected from the catch landings of the two countries concurrently, and it was identified using a previously employed DNA barcoding technique. A total of 221 and 210 specimens of L. ehrenbergii collected from the catch landings of the Red Sea, Egypt, and the Arabian Gulf in Qatar, respectively, were employed for the purpose of the current study.Fish were dissected to determine their sex after measuring the total length (TL) for each specimen to the nearest 0.1cm and calculating the total weight to the nearest 0.1g. Ages were calculated through the reading of otolith growth rings. For L. ehrenbergii from the Red Sea, the results of the von Bertalanffy growth parameters were L_∞ = 35.6cm, K = 0.32y^⁻1, and t_o = - 1.30 year for L. ehrenbergii from the Red Sea, and L_∞ = 34.8cm, K = 0.32y^⁻1, and t_o = - 1.40 year for L. ehrenbergii from the Arabian Gulf. Otolith growth rings revealed a maximum lifespan of 4 years. Kc values for L. ehrenbergii samples from the Arabian Gulf ranged from 1.30 to 1.47, whereas samples from the Red Sea exhibited values between 1.28 and 1.48. L. ehrenbergii exhibits a negative allometric growth, reflected by the weight of pooled sexes increasing in proportion to less than the cube of their body length (b= 2.926 to 2.942 in fish from the Red Sea and 2.876 to 2.881 in fish from the Arabian Gulf. The current study indicates that geographical or sex-specific variations in growth should be considered upon assessing the significance of growth studies for managing fish stocks.