Prevalence and Intensity of Parasitic Infection in Cultured Milkfish (Chanos chanos Forsskal, 1775) in Sarangani Bay, Southern Mindanao

This study aimed to assess the parasitic infection in milkfish (Chanos chanos) reared in sea cages in Sarangani Bay, Philippines. The objectives were to identify parasites in milkfish, determine the prevalence and intensity of parasitic infection, and correlate fish fresh weight to the number of parasites present. A total of 120 milkfish samples were collected randomly from fish cages in Sarangani Bay from December 2022 to January 2023. The fish were examined for ectoparasites and dissected to inspect endoparasites. Parasites were identified using taxonomic guides and books on parasitology. Results showed no ectoparasites on the milkfish samples. However, 24% of the samples were infected with three endoparasities: Anisakis sp., Contracaecum sp., and Diphyllobothrium latum. The most prevalent endoparasite was Anisakis sp. (12.5%), followed by Contracaecum sp. (8.33%), and Diphyllobothrium latum (3.33%.) Contracaecum sp. had the highest mean intensity of 1.51 found in the intestines of C. chanos. Anisakis sp. had a mean intensity of 1.44 found in the fish stomach, while D. latum had the lowest mean intensity of 0.44 found in the intestines. Fish fresh weight showed negative but weak correlation with the number of endoparasites, with a correlation coefficient of -0.1049, indicating that other factors, such as environmental conditions, may play a more significant role in determining parasite load in fish.