ABSTRACT
This contribution deals with the scanning electron microscopic surface structure of olfactory epithelium in four hillstream teleosts from the glacialfed river Alaknanda in Garhwal Himalaya (UP, India)· The closely related species—Schizothorax plagiostomus, Schizothorax richardsonii (both bottom dweller, bottom feeder, herbiomnivorous) and Schizothoraichthys progastus (column dweller, column feeder, carniomnivorous) reveal the predominance of different types of olfactory receptor cell types separately in their respective olfactory epithelium while the distinctly related species Crossocheilus latius latius with similar nature as first two (i·e· bottom dweller, bottom feeder, herbiomnivorous) displays the presence of more microvillous cells in the olfactory epithelium· Possibly, the occurrence of particular receptor cells in a fish species is related to the ecological and feeding behaviours with distinct mechanism of olfaction·