Inventory of Freshwater Fish Parasites in Tarakan City, North Kalimantan, Indonesia

Parasitic infections pose potential threats to fish health and freshwater aquaculture productivity. This study aimed to identify parasite taxa and determine their prevalence and mean intensity in cultured freshwater fish in Tarakan City, North Kalimantan, Indonesia. The study was conducted in May 2026 at the Fisheries Biology Laboratory, Borneo Tarakan University. A total of 60 juvenile fish, comprising 30 Nile tilapia and 30 catfish, were collected from aquaculture ponds. Ectoparasites and endoparasites were examined through microscopic observations of mucus, skin, gills, intestines, and muscle tissues. Parasites were identified based on morphological characteristics, and their prevalence and mean intensity were analyzed descriptively. Seven parasite genera were identified, comprising five genera in Nile tilapia and six in catfish. Trichodina sp. exhibited the highest prevalence in both Nile tilapia (100%) and catfish (100%), with mean intensities of 66 and 9 parasites/infected fish, respectively. In Nile tilapia, Gyrodactylus sp. (60%), Argulus sp. (40%), Dactylogyrus sp. (20%), and Centrocestus sp. (20%) were also identified. In catfish, Ichthyophthirius sp. exhibited a prevalence of 60% and the highest mean intensity (151 parasites/infected fish), followed by Dactylogyrus sp. and Gyrodactylus sp. (40% each), and Centrocestus sp. and Oodinium sp. (20% each). These findings demonstrate the occurrence of multiple parasite taxa in cultured freshwater fish and highlight the importance of regular parasite monitoring and health management in freshwater aquaculture.