​Fish Diversity, Conservation Status and its Relationships with Environmental Variables in Umtrew River System, Northeast, India

Abstract

Background: River water and its faunal diversity are regarded as an integral part of the environmental stability and river ecosystem. To know the abundance and diversity of fin fishes in relation to their environmental parameters, a hilly river Umtrew in Meghalaya and Assam was investigated during January, 2019 to December, 2020. Methods: Fish, plankton and water samples were collected regularly at monthly intervals for a period of 24 months. Standard protocols were followed for analysis of the collected samples. Result: A total of 49 fish species under 36 genera, 20 families and 10 orders were recorded. Among them Cypriniformes (42%) is the dominated order followed by Siluriformes (24%). As per IUCN status 1 species falls under critically endangered, 4 species are near threatened, 2 species under vulnerable and 42 species are of least concern. A significant correlation between species distribution and environmental variables was also reported. Our findings clearly oppose the tendency for species composition to increase from the source to the mouth of the river, which is probably prohibited by two major anthropogenic activities. These activities could constitute in the future a real threat for the fish population and other aquatic organisms.