Avinash Kumara, Jai Nandan Prasad Yadava & Arun Kumarb*
aDepartment of Zoology, K. P. College Murliganj, B.N.M. University, Madhepura, Bihar, India
bUniversity Department of Zoology, B.N.M. University, Madhepura, Bihar, India
Received : 15th October, 2021 ; Revised : 16th December, 2021
Abstract– The study was conducted to explore the zooplankton composition and abundance in freshwater perennial ponds, locally named as Puraini Pokhar (Pond 1) and Baghmara Talab (Pond 2) located at Madhepura district, North Bihar. Water and zooplankton samples were collected monthly from March, 2019 to February, 2020. The investigation on physico-chemical characteristics at both the ponds revealed its alkaline nature, suitable for aquaculture practices. Four groups of zooplankton viz. Rotifera, Cladocera, Copepoda and Ostracoda comprising of total 26 species were identified.Of these 23 species consisting 13 species of Rotifera followed by Cladocera 5 species, Copepoda 4 species and Ostracoda 1species were recorded from Pond 1, though, 17 species comprising 11 species of Rotifera followed by Cladocera and Copepoda 3 species each were identified from Pond 2. Zooplankton abundance ranged from 82 ind./l to 318 ind./l in Pond-1 and from 54 ind./l and 376ind./ l in Pond-2. Zooplankton density was minimum during monsoon and maximum in summer. Percentage compositions showed dominance of Rotifera contributing 55.56% followed by Copepoda 22.53%, Cladocera 20.73% and Ostracoda1.18% in total zooplankton abundance in Pond 1, while, Rotifera contributing 57.75%, followed by Copepoda 23.04% and Cladocera 19.86% in Pond 2. Most dominant rotifers were Brachionus angularis, Brachionus caudatus, Brachionus falcatus, Filinia longiseta and Keratella tropica in the studied ponds. No important differences were observed in abundance of Cladocera and Copepoda. Among cladoceran group, Daphnia sp. were found most dominant followed by Moina dubia. Copepoda was dominated by Nauplii. Sørensen’s similarity index was applied to assess similarity in the species composition among the ponds. Index values showed highest similarity in copepods species 85.71% followed by rotifers 75% and cladoceran 50%. The distribution and density of zooplankton was influenced by physical and chemical factors of the pond environment were discussed.