Studies on certain aspects of behaviour in the blind catfish Horaglanis krishnai Menon

Abstract

Horaglanis krishnai is a blind catfish inhabiting the dug-out wells at Kottayam, Kerala. This fish has great zoogeographical importance as a similar blind clariid, Uegitglanis zammaroni is found only in the artesian wells of the former Italian Somaliland. Studies on certain behavioural aspects of the fish in captive conditions showed that, this fish even though is blind, exhibited a high degree of thigmotactism. Locomotion, comfort behaviour, feeding and light sensitivity of the fish were studied under laboratory conditions. Though the fish is totally blind and histological study did not reveal the presence of any light sensitive structures, the fish is found to be sensitive to light stimulus. It is a predator. Under laboratory conditions it unerringly snapped up food organisms. This is obviously facilitated by the high degree of development of the tactile and olfactory sense organs.