HILL STREAM ICHTHYOFAUNAL DIVERSITY OF BAKSA DISTRICT ALONG THE INTERNATIONAL BORDER BETWEEN INDIA AND BHUTAN: ECONOMIC IMPORTANCE AND ANTHROPOGENIC THREATS

North-Eastern states are leaders in the diversity of indigenous species of economically important fish. Hill streams of this region inhabit ichthyofauna of broad importance. However, increased anthropogenic activity possess deleterious consequence. The goal of the study conducted from January 2021 to July 2022 was to document and report the ichthyofaunal diversity of the hill streams in the Baksa district of Assam, India, its economic importance as well as potential threats associated with it. A total of 3182 fishes classified into 39 species, 13 families, and 5 orders were documented. Cypriniformes is the dominant order (71.24%), followed by Perciformes (17.76%), Siluriformes (5.97%), Symbranchiformes (3.65%), and Beloniformes (1.38%). These hill streams inhabit endangered, vulnerable, near-threatened, lower-risk-near-threatened species (IUCN, CAMP, and ICAR). Diversity indices indicate that these streams are rich in evenly distributed ichthyofauna. However, the recent spike in riparian deforestation, illegal fishing, and tourism-related plastic garbage possess a serious threat to these hill-stream ecosystems and inhabiting fish fauna. The consequences of riparian deforestation are looming as a severe future issue. Conservation of this ecosystem has become an important call to take on.