DESMIDS BIODIVERSITY IN FRESHWATER PONDS OF DISTRICT NAGAUR, WESTERN RAJASTHAN INDIA: A PRELIMINARY INVESTIGATION

The present study was carried out to investigate the desmids biodiversity in traditional freshwater reservoirs of Nagaur district, Western Rajasthan, India. The samples were collected in January 2021 from the freshwater small ponds which harvests rainwater located in and around Nagaur city. These samples were analyzed by following the standard method prescribed by A.P.H.A for assessing the various physicochemical parameters such as pH, TDS, Fluoride, Nitrate, Chloride, total alkalinity, and total hardness to check drinking water quality and for ecological assessment. Furthermore desmids species-level identification and description have been done with the help of standard literatures and monographs. Results of physicochemical parameters indicate the deteriorating drinking water quality of all four sampling sites. In the present study total of 16 species belong to 5 genera i.e. Netrium, Closterium, Cosmerium, Staurastrum, and Eustrum of desmids have been recorded for the first time from the freshwater ponds located in or around the Nagaur city. The higher biodiversity of Closterium and Cosmarium species at Jhada talab confirm its significant relationship with high calcium and nutrient-rich water quality. While low biodiversity of desmids at remaining all village ponds indicates that high pH and oligotrophic quality decreases the desmids biodiversity. Results of this study might be helpful to assess the geographic distribution of desmids flora of Nagaur district and establish water quality of protected freshwater habitats as well as in updating the list of current species of desmids in this sub-region.