Corneal hypertrophy in farmed chocolate mahseer, Neolissochilus hexagonolepis, from (Uttarakhand), India

Abstract

Corneal hypertrophy was observed in fingerlings of chocolate mahseer, Neolissochilus hexagonolepis (McClelland, 1839) from Uttarakhand, India. The advanced stage of infection was marked with damage of cornea and shrunken eye. Skeletal deformity was also recorded in some of the infected fishes. Samples of eye and other organ were collected for histopathological, parasite and microbial investigation. Histological examination of the eye indicated ocular collapse, entirely damaged cornea, disruption of vitreous, aphakic globe, oedema of choroid and optic nerve and, deformed retina. Microscopic observations of wet mounts and histopathology ruled out infectious agents like microsporidia, myxosporidea, cystercoidiasis, atypical mycobacteria, digeneans and fungi. PCR for viral aetiology did not yield any significant amplicons. Further detail study related to physic-chemical parameter need to be carried out to ascertain the exact cause of this disease.