Heavy infection of Ichthyophthirius multifiliis in striped catfish (Pangasianodon hypophthalmus, Sauvage 1878) and its treatment trial by different therapeutic agents in a control environment

ABSTRACT

Striped catfish (Pangasianodon hypophthalmus) fingerlings were stocked (60 fishes/m³) in cemented square tanks for ornamental fishery purposes at the College Fish Farm in Mangalore. A total of 400 fishes with a mean weight (g) ranging from 3.24 ± 1.21 to 6.70 ± 1.13 and a mean length (cm) of 7.50 ± 0.94 to 9.50 ± 1.10 were examined. A severe outbreak of salt-like granule white spots was found on the body surface. 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: (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.

KEYWORDS:

• White spot
• Pangasianodon hypophthalmus
• Ichthyophthirius multifiliis
• Mangalore
• treatment
• Epistylis

Acknowledgments

We thank Dr. K. S. Ramesh, Head of the Aquatic Health Management Laboratory, College of Fisheries, Mangalore, for the technical support to carry out this work. The authors are very grateful to and kindly acknowledge the reviewers for their careful and meticulous reading of the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The first author is grateful to the ICAR for providing the Netaji-Subhas International Fellowship.