author(s)
Manokaran Kamalakannan and Joy Krishna De

abstract
The dorsal guard hair of three Indian otter species namely, Aonyx cinerea, Lutra lutra, and Lutrogale perspicillata were examined using the optical light microscope at the Zoological Survey of India, Kolkata during January – July 2016. The microscopic characteristics of hair of two species Aonyx cinerea and Lutra lutra showed almost similar characteristics, however, the cross-section of hair is varied between the two species. But the microscopic hair characteristics of Lutrogale perspicillata having different hair characteristics viz., ‘unicellular irregular’, ‘ladder’ medulla and ‘irregular’ cuticular scale patterns and these unique characteristics make the difference between the other two species (Aonyx cinerea and Lutra lutra) studied. The high-resolution photo-micrographs and key characteristics of hair were presented here can be used as an appropriate reference for species identification.