Assessing the Size-Structured Stock of the Swimming Crab <i>Callinectes amnicola</i> (Crustacea: Portunidae) in the Cross River, Nigeria

Abstract An important aspect of the size-structured stock is assumption that individuals progress from one size class to another after a certain time. In this study, total 2581 monthly samples swimming crab Callinectes amnicola were collected landings artisanal fishery in Cross River, Nigeria over period 13 months, January 2021 2022. Crabs ranged length 6.5 cm 15.5 cm, with most crabs caught during dry season. The fewest (n=23) August 2021, and (n=662) 2021. Because moulting other physiological obstacles make it difficult determine age, frequency data used instead. Swimming assessment was based on some basic growth parameters von Bertalanffy function Beverton Holt model. results showed asymptotic rate 16.28 0.940 per year, respectively. best index estimated be 2.40, while longevity mortality 3.19 years 3.46 calculated exploitation 0.41 below guideline 0.5 maximum yield recruit 0.421, confirming an underfished stock. Sustainable River recommended by reducing efforts already exploited resources.