Research Article: Population dynamics of Parapenaeus longirostris (Decapoda: Penaeidae) (Lucas, ۱۸۴۶), in Central Algerian waters (South-Western of Mediterranean Sea)

The deep-water rose shrimp, Parapenaeus longirostris (Lucas, ۱۸۴۶), has an important economic value in the Algerian market. This work aimed to fill the knowledge gap on the species through the study of growth, mortality, and exploitation rate. The samples of P.longirostris were collected monthly in the Bou-Ismail Bay from ۲۰۱۶ to ۲۰۱۸. The carapace length (CL) of the females and males ranged from ۱۵ to ۴۳ mm and ۱۴ to ۳۸ mm with averages of ۲۸.۹۹±۴.۷۶ mm and ۲۵.۸۲±۳.۹۲, respectively. The species shows a sexual size dimorphism. The CL and total weight relationship established that growth in both sexes was negatively allometric. The Von Bertalanffy Growth Function parameters for females and males were CL∞=۴۸.۸۰ mm, K=۰.۶۰ year-۱, and CL∞=۴۱.۴۰ mm, K=۰.۶۲ year-۱, respectively. The instantaneous rates of total mortalities (Z) were ۲.۶۶ year-۱ for females and ۲.۰۳ year-۱ for males. The exploitation rates were ۰.۶۶ and ۰.۴۹ for females and males, respectively. The length at first capture for males and females is equal to ۱۶.۳۰ mm, ۱۷.۱۴ mm, respectively. The result indicates a beginning of the overfishing situation for P. longirostris. Thus, it encourages undertaking stock assessment studies in the area.

Keywords:

Growth , Mortality , Exploitation rate , Parapenaeus longirostris , Bou-Ismail Bay , Fishing