author(s)
Banothu Raveendar, AP Sharma, Udai Ram Gurjar, Ravi Gugulothu and Ashutosh Mishra

abstract
The present study was conducted to assess the limnological characteristics and ichthyofaunal diversity in Nanaksagar reservoir, located in Tarai region of Uttarakhand. Along with water quality parameters and fish communities was done in Nanaksagar reservoir. Monthly samplings were conducted at three selected sites during August 2016 to March 2017. A total number of 30 species of fishes were recorded during the study period. The fish data is subjected to species diversity analysis. As per values of Shannon (2.118 – 2.612) and Simpson diversity (0.822 – 0.8954) indices fish community of the reservoir is diverse. The range of Margalef and Menhinick species richness indices (3.253 – 3.782 and 0.9183 – 1.065, respectively) indicates moderate fish species richness. The evenness index was maximum (0.5453) in month of March, 2017 showing maximum dominance of different species. The average fish production of Nanaksagar reservoir during investigation period was calculated as 45.07 kg/ha. Fish production was found to be positively correlated with total alkalinity (0.92), DO (r=0.84), pH (r=0.79), transparency (r=0.47) and specific conductivity (r=0.18).