Faunal composition and abundance in temporary aquatic habitats of southwestern Ethiopia

Abstract

The study was conducted in a small rural village called Waktolla, within Jimma Zone of Oromia National Regional State, where there were burrow pits of various sorts. The objective of the study was to make an inventory data on the diversity of aquatic animals on these least studied habitats. A scoop net with a mesh size of 1 mm was used to sweep the water for a length of 1 m. A total of 19,678 aquatic animals were sampled from 79 burrow pits during the two peak rainy months, August and September, 2011. The only vertebrate representatives, tadpoles of order Anura comprised only 8.1% of the total faunal collection and the rest was comprised by invertebrates (91.9%). Insects and nematomorphs were found to be the most (59.1%) and the least (0.3%) abundant invertebrates, respectively. The organisms in Class Insecta were grouped into 7 Orders (which except Order Collembola could be further identified to families): Orders Diptera (12), Ephemeroptera (2), Hemiptera (11), Coleoptera (4), Odonata (2), and, Lepidoptera (1), with dipterans and collembolans being the most (36.9%) and the least (0.4%) abundant insects, respectively. Invertebrates in subphylum Crustacea were classified into Class Ostracoda, and Orders Cladocera and Cyclopoida, which except Ostracodas were identified into two and a single family, respectively. The most and least abundant crustaceans were cladocerans (71%) and cyclopoids (0.1%), respectively. Class Gastropoda was also identified into 2 families, but the remaining animals in Orders Araneae and Anura, Class Oligochaeta, Phyla Nematoda and Nematomorpha could not be identified to successive lower taxa. It is anticipated that as such type of inventory work continues in different water bodies of Ethiopia, catalogues and keys of aquatic invertebrates of the country will be developed.

Keywords/phrases: Abundance, Aquatic fauna, Burrow pits, Composition, Taxa