Ichthyofaunal diversity of Senkhi stream, Itanagar, Arunachal Pradesh: a comparative status between 2004-05 and 2018-19.

An investigation was conducted during 2018-19 after a time span of 13 years in the Senkhi stream, an important hill stream that flows through western corner of the capital city, Itanagar. The present study aims to compare decadal changes in ichthyofaunal diversity, status, and abundance with reference to the impact of increasing urbanization in the capital city. The ichthyofaunal diversity assessed presently is restricted to 37 species spreading over 30 genera under 13 families which include four species more, not reported in the past. Thus, of the 37 species recorded, 33 species only could be compared, and noticeably resulted ultimate reduction of 14 species belonging to 11 genera under 10 families from the study area. It indicated that nearly 64% decline in fish abundance within stream zone under urban area and about 46% reduction in undisturbed area. The present study hitherto revealed the alarming rate of decline in fish diversity and also unfolded key factors responsible for crucial decline of fish diversity along with the possible mitigation measures. [ABSTRACT FROM AUTHOR]