Abundance and Seasonality of Phytoplankton, Zooplankton and Anuran Species in Selected Wetlands of Kogi State, Nigeria

Phytoplankton, Zooplankton and anurans play vital role in the working of wetland ecosystems as they form its dynamic food web. This study was designed to determine the abundance and seasonality of Phytoplankton, Zooplankton and Anuran species in selected wetlands of Kogi State, Nigeria. The study was performed in Abu’ja wetland in Dekina Local Government area and Egwubi seasonal wetland in Ejule, Ofu Local Government area of Kogi state. From each sampled wetlands planktons were collected with plankton net at the sites. Overall, 854 specimens of anurans, 584 from Abu’ja and 270 from Egwubi sites were collected within a period of eighteen months. The abundance of phytoplankton, zooplankton and anuran species were computed. Abundance was computed as a proportion of numbers of organisms in a group to the summation of the total number in all the groups being considered. Simpson’s index (Dominance), Gini-Simpson's, Shannon-Wiener index, Berger-Parker index, Margalef’s index, Menhinick’s index, Fisher alpha, Equitability index, Brillouin index and Chao index were all calculated following standard methods. The data collected was analyzed using the Statistical Package for Social Sciences (SPSS) version 20.0, PAST version 3.14 and Microsoft Office. Level of significance was p < 0.05. Anuran species found in both wetlands included Amietophrymus regularis, A. maculatus and Hoplobatracchus occipitalis. Phytoplankton species encountered in both study stations include Oscilatoria spp, Anabaenia spp, Anacystis spp, Spirogyra spp, Oedogonium spp, Savicular spp and Euglena spp. Zooplanktons encountered include Epiphanes spp, Philodina spp, Synchata spp, Poliathra spp, Holopedium spp, Daphnia spp, Alona spp and Bosmina spp. The abundance and seasonality of phytoplankton, zooplankton and anurans in the selected wetlands studied in Kogi state, Nigeria showed that the organisms abundance are highly influenced by the seasons in Kogi State, with its peak abundance in rainy season and very low abundance in dry season.