Pengaruh Kepadatan Tebar Terhadap Perilaku Agonistik Dan Kanibalisme Pada Ikan Patin (Pangasius sp.) Dalam Wadah Terbatas

Abstract

Pangasius (Pangasius sp.) is a leading freshwater fishery commodity in Indonesia, but its success is greatly influenced by stocking density, especially in confined spaces. High stocking density can lead to competition for space and food, thereby triggering aggressive behavior and cannibalism among individuals. This study aimed to examine the effect of placing patin fish in small tanks on the occurrence of cannibalistic behavior. Observations were conducted on ten patin fish reared together in a single 18-liter bucket for seven days, at a stocking density of approximately 0.56 fish per liter of air. Visual observations were conducted periodically to identify the presence of wounds, fin or tail damage, and indications of aggressive behavior among the fish. The data obtained were descriptive and qualitative. The results of the observations showed that one smaller fish suffered complete loss of its tail after being preyed upon by another individual and subsequently died, while the other nine fish showed no injuries. The survival rate was 90%, with a cannibalism index of 10%. This case falls under Type A cannibalism, which refers to death resulting from the loss of vital body parts necessary for movement. These findings indicate that the primary trigger for cannibalism is not just overall stocking density, but rather the striking differences in body size among individuals within a single tank. Therefore, standardizing fry size and adjusting the number of fish to the tank volume should be a top priority in small-scale catfish farming to reduce the risk of cannibalism and improve fish survival.