Out of 23 species of crocodilians found in the world , three species found in India Crocodylus palustris, Crocodylus porosus, Gavialis gangeticus. The Crocodylus palustris distributed throughout the Indian subcontinent is primarily found in freshwater lakes, marshes and rivers, or any other area that is slow moving and shallow and avoid salty condition. The Gavialis gangeticus, endemic to the Indian subcontinent, was once common in the river systems of Pakistan, Northern India, Bangladesh, Myanmar, Bhutan and Nepal. But they are now restricted to a few, scattered locations in India and Nepal. The population of gavial regularly decreases due to land-use changes, reduction in water flow, modification of river morphology, loss of nesting sites, increased mortality in fishing nets, poaching for skin and is especially at risk from flow regulation because it prefers fast-flowing river habitats. The population of gavial in the stretch of 142 km (Rangpur Ghat to Pali bridge) was recorded 45 in 2013 during dissertation study in National Chambal Sanctuary.