The occurrence and abundance of zooplankton depends on its productivity, which in turn is influenced by physico-chemical parameters and the level of nutrients in the water. The zooplankton community constitutes an important component of aquatic ecosystem and important role in the trophodynamics cycling and aquaculture productivity. Rotifera is the dominant group amongst the zooplankton of which Brachionus is most dominant genera belongs to class monogonanta. Present study deals with the abundance and correlation of two fresh water Brachionid species i.e. Brachionus calyciforus and Brachionus falcatus with respect to physico-chemical parameters of Upper Dudhana dam, which is located in Jalna district (M.S.) India. The water samples were collected for a period of one year and analyzed for determination of (Water Temperature, pH, Transparency, Total Alkalinity, Chloride, TDS, Total Hardness, Ca, Mg, DO and BOD) during the period of sampling from Feb.2014 to Jan.2015. Result showed that the density of Brachionus calyciforus was maximum (54.5 org/L) in June and minimum or absence of this species in the month of October. Similarly Brachionus falcatus showed maximum density (15.75 org/L) in April and minimum or absence of the species in the month of January. B. calyciforus showed positive high significant correlation with Chloride and B.falcatus with TDS at 1% level. It concluded that abundance of these species is strictly correlated with physico-chemical parameters of water.
