Identification of Vermamoeba vermiformis and Tetramitus sp. Isolated from the Gills of Oreochromis sp. (Red Hybrid Tilapia)

This study is the first report of an infestation amoeba in gills asymptomatic Oreochromis sp. from Manir River, Terengganu, Malaysia. The results confirmed presence two species amoeba, Vermamoeba vermiformis and Tetratmitus sp., based on 18 ribosomal RNA gene sequences with 99% sequence similarity. Morphological observations using light scanning electron microscopy supported findings, demonstrating both species' specific features locomotions. In trophozoite stage, mean size V. locomotive form was between 25.55 µm length 4.17 width. Tetramitus 20.96 8.66 diameter cyst for 4.67 3.37 µm. characterized by cylindrical trophozoites single monopodial morphology. showed a limax-type various cell shapes. Infestation also histopathological observation lamella region distinct characteristics compared to lamellae's epithelial tissue. These findings revealed its potential pathogenic activity, whilst symbiosis interaction still unidentified.