Zooplankton composition, abundance and diversity in Sagartaal, Budaun district, Uttar Pradesh, India

Sagartaal is located in Budaun with geographical coordinates 28.0512°N and 79.1305°E in Nawada region, Uttar Pradesh, Uttar Pradesh, India. Understanding the composition, diversity, and abundance of the zooplankton is vital for better utilization of such waterbodies. The present study was carried out from October 2022 to September 2023. A total of 24 species belonging to 16 species of Rotifera, 4 species of Cladocera, 2 species of Copepoda, and 2 species of Ostracoda were recorded. The prominent species were Brachionus forficula, B. calyciflourus, Keratella cochlearis, Simocephalus sp., Cyclops sp., and Mesocyclops sp. Zooplankton showed seasonal variations in their species composition, abundance, and diversity concerning water temperature, pH, total alkalinity, dissolved oxygen, and hardness. The zooplankton density was recorded as maximum in winter and minimum in monsoon. Statistically, zooplankton shows significant correlations as Rotifera with EC, BOD (r =− 0.50; − 0.58, respectively); while with total hardness (r = 0.75); Cladocera with DO (r = 0.53), alkalinity (r = 0.57), nitrate (r = 0.56), and phosphate (r = − 0.49). The highest Shannon index (2.83) was obtained for summer, due to the lowest value of the dominance index (0.07) for this season. More studies are warranted on Monitoring such ecosystems as Sagartaal to understand the effects of anthropogenic pressure on zooplankton's community structure, can help in identifying the indicator species to formulate effective conservation planning.