Diversity and Population Dynamics Of Freshwater Cladocera (Crustacea: Branchiopoda) In Manmade Ponds At Boye Wetland, Jimma Zone, Southwestern Ethiopia

Abstract

A study was carried out on the diversity and population dynamics of the freshwater Cladocera from March, 2013 to August, 2013 in three manmade ponds in Boye wetland. Samples were taken fortnightly with concurrent measure of influencing variables like air and water temperature, pH, dissolved oxygen (DO), electric conductivity (EC) and transparency were measured. Except for EC no significant differences were recorded for water temperature, pH, DO and transparency among these three ponds but there were significant differences in water temperature and transparency between months. During this study a total of 7 species of Cladocera belongs to 7 genera and 5 families were recorded. Among the five families the Daphnidae and Chydoridae were represented with 2 species each, while Moinidae, Macrothricidae and Sididae represented with 1 species each. The Cladocera species identified during this study include Moina micrura, Diaphanosoma excisum, Alona rectangula, Ceriodaphnia cornuta, Daphnia lumholtzi, Chydoruss sphericus and Macrothrix laticornis. The Moina micrura, Diaphanosoma excisum were the dominant specie, while Daphnia lumholtzi, was the least abundant Cladocera species. The number of species was not too different among the three ponds, however, average Cladocera abundance, was significantly higher (P<0.05) at the pond I and III than pond II. Peak in average abundance of Cladocera species was observed during May and August (139 and 125 ind/L) respectively and the lowest abundance were 102 and 116ind/L observed in March and July. In general, the greatest species richness of Cladocera at the order level was recorded at pond I and III. The diversity (H') and evenness (J') indices were higher at pond III. As present study was a preliminary attempt to know the taxonomy, abundance and periodicity of cladocerans, more studies will be required to make a complete list of available Cladocera species as well as their impact on water quality in the manmade ponds at Boye wetland.