Scanning Electron Microscopic Surface Study of Adhesive organ of Garra gotyla gotyla (Gray)

Abstract

An attempt to study the adhesive organ of Garra gotyla gotyla inhabiting hill streams of Aravalli region has been made using scanning electron micro-scope. The results were compared with that of scanning electron microscop-ic studies of the adhesive organ of G. gotyla gotyla of the Himalayan region. The SEM study reveals that the upper fringed lip (UFL)and the lower lip or the posterior free labial fold (PFLF) bears short stub shaped tubercles (ST). These tubercles in turn bear numerous spines (S). The tubercles are covered with squamous epithelium (SE) indicating that spines are modified squamous epithelial cells. The margins of stub-shaped tubercles bear smaller spines; their size increases from margin to the centre. The surface ultrastructure of the adhesive disc of G. gotyla gotyla revealed the presence of hexagonal epithelial cells with elevated cell boundaries. Each spine is attached to callous pad with a broad base. The spines are used for anchorage to the substratum so that fish can scrap food even in fast current of water. Tubercles are used by fish for protection against mechanical injuries. Further these may be taxo-nomically used for conspecific recognition. Cumulative action of tubercles and mucus enables the fish to make firm hold on the substratum.