Reproductive biology of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the southern waters of West Java (FMA 573)

Abstract

Indian mackerel is a small pelagic fish with important economic value in Java Island. This study aims to analyze the reproductive characteristics and determine management recommendations for the Indian mackerel in the southern waters of West Java. Fish monthly sampling collection was conducted at three fish landing ports: PPI Ciwaru, PPN Palabuhanratu, and PPI Binuangeun from July to December 2022. A total of 1,038 fish samples, comprised of 582 males and 456 females, were examined. The sex ratio was unbalanced, with a value of 1:0.79. Gonadosomatic indexes ranged from 0.19-0.95 and 0.45-3.41 for males and females, respectively. The fish fecundity ranged from 27,027 to 87,837 eggs. The Indian mackerel is predicted to spawn every month, with a peak season in August, and performs a total spawner pattern. The Indian mackerel reached the size of the first maturity gonad at 198.5 mm and 197 mm for males and females, respectively. Management strategies for Indian mackerel in the southern waters of West Java include setting the catch size above the first mature gonad size (197 mm), the mesh size of gillnets above 1.5 inches, and limiting fishing activities during the spawning season (July, August, and September).