HEAVY INFECTION OF Ichthyophthirius multifiliis IN THE STRIPED CATFISH Pangasianodon hypophthalmus (SAUVAGE, 1878) AND ITS TREATMENT TRIAL BY DIFFERENT THERAPEUTIC AGENTS IN CONTROL ENVIRONMENT
Striped catfish, Pangasianodon hypophthalmus fingerlings were stoked (60 fishes/m3) in the cemented square tanks for the ornamental fishery purposes at College Fish Farm, Mangalore. Total 400 fishes with mean weight (g) ranging from 3.24 ± 1.21 to 6.70 ± 1.13, and mean length (cm) 7.50 ± 0.94 to 9.50 ± 1.10 were examined, found severe outbreak of salt like granule white spots on body surface. The Ichthyophthirius multifiliis, a ciliate pathogen, was identified as the causative agent by clinical signs, wet mount and histopathological observations. Infected fishes were transferred and equally distributed to the 0.45 m3 glass aquaria and treated with three treatments viz. T1) Methylene blue + salt, T2) Raising temperature with salt and T3) Formalin + Malachite green. The best fingerling survival (55±9.36%) was obtained by elevated water temperature with salt in T2.
The I. multifiliis, a ciliate pathogen (Fig1A-D) was identified as the causative agent by clinical signs, wet mount and histopathological observations. The outbreak (Prevalence, 100%) of white spots disease resulting from I. multifiliis infection might be associated with lowered water temperature during Monsoon season where heavy rain lashed out in the study area (Mangalore).
