Skeletal deformities of few freshwater fishes from Bhavani River, Tamil Nadu

Abstract

Manuscript 1145; Received 5 February 2004; Revised received 31 May 2004; Finally accepted 10 July 2004; © Zoo Outreach Organisation; www.zoosprint.org 1628 Deformities in teleosts are occasionally found in natural and/ or wild population. Such phenomenon is quite common among the animals kept in zoos for captive propagation (Sennar, 1980; Tutman et al., 2000). Several studies have focused on the deformities of the skeletal region, and a wide range of causes has been noticed, including genetic variance (hereditary factors), inbreeding depression, significant ecosystem changes viz., temperature, pH, parasitism, nutritional deficiencies and environmental contamination (from pollutants) (Orska, 1962; Koumoun-douros et al., 1997). Numerous reports are available regarding the present study in other species viz., Cirrhinus mrigala and Hypothalmichthys molitrix (Panday & Awasthi, 1994) probably due to inbreeding depression. Similar abnormal features have also been observed among a few endangered fish species, namely, Salmo trutta (Poynton, 1987), Micropterus dolomieni (Avyle et. al., 1989) and Oncorhynchus mykiss (Madsean & Dalsgard, 1999). The present study reports the skeletal deformities found in wild populations of a few freshwater catfishes Mystus cavasius, Ompok bimaculatus and Heteropneustes fossilis, murrel Channa striatus and C. puntatus and featherback Notopterus notopterus.