Population Dynamics and Stock Assessment of Deep-Water Red Shrimps Aristaeomorpha foliacea and Aristeus antennatus in the Southeastern Mediterranean Waters

The stock status of the two deep-water red shrimps (DWRS), Aristaeomorpha foliacea (ARS) and Aristeus antennatus (ARA) in the Southeastern Mediterranean (the Egyptian Mediterranean waters) was assessed. The length-based spawning potential ratio (LB-SPR) model was used for the assessment. The input data depended on a scheme of data collection for two years after identifying the fishing grounds of the DWRS. The von Bertalanffy growth parameters were estimated by analyzing the length frequency distributions, where the growth coefficient (K) = 0.41 year^-1, the asymptote carapace length (L_∞)=65.01 mm, and the theoretical age at length 0 (t₀)= -0.12 year for ARS, while they were K= 0.35 year^-1, L_∞= 57.51 mm, and t₀= -0.50 year for ARA. The average of natural mortality vector (M) was 0.8 for ARS, and 0.77 for ARA. Carapace length at 50% sexual maturity (L₅₀) was 32.85 and 26.31mm for females of ARS and ARA, respectively. The mean spawning potential ratios SPR (0.062 and 0.17) and the mean ratios of fishing mortality to natural mortality F/M (2.91 and 1.47) for ARS and ARA, respectively, revealed that the two stocks are overexploited. In the context of fisheries sustainable exploitation, a management plan is therefore needed to regulate the fisheries of the two studied species in the Egyptian Mediterranean waters.