The Zooplankton Species Composition and Abundance in Sombreiro River, Niger Delta, Nigeria

E.N. Ezekiel ； E.N. Ogamba ； J.F.N. Abowei

《Asian Journal of Agricultural Sciences》 3卷3期 (2011/05) Pp. 200-204

並列摘要

The zooplankton species composition and abundance in Sombreiro River, in the Niger Delta of Nigeria was studied for a period of two years (August, 2007-July, 2009), using filtration technique. 25 μm mesh size plankton net was towed from a dugout boat at about 5-105^(–1) for about a minute. The net content was washed out into a wide mouth plastic container and preserved in 10% formalin solution after proper labeling. A total of seventeen (17) species belonging to six (6) taxonomic groups were recorded from Sombreiro River. The groups Cladocera and Copepoda were represented by five species each consisting of 29.4% by composition. This was followed by three species of Protozoa (17.6%), two species of Rotifera (11.8%), Decapod crustacean (5.9%) and Euphasiacea (5.9%), one specie each. Copepoda was the highest, 46.5%. This was followed by Cladocera (23.3%). The others were Protozoa (11.2%), Euphasiacea (9.6%), Rotifera (7.9%) and Decapod Crustacean (1.5%). The low zooplankton diversity observed in this study is common in tropical waters. The dominance of cladocera and copepoda in the study area is common to River Nun, in the Niger Delta and Schelde estuary in Belgium. Sombreiro River zooplankton abundance is higher than that of River Nun but lower than that of Imo River in the Niger Delta. These differences are attributed to duration of sampling and natural conditions of the water bodies. The zooplankton abundance was well distributed in the stations except Mysis sp. (Decapod Crustacean) which showed spatial discontinuity in abundance.

並列關鍵字

Abundance ； composition ； Niger Delta ； Nigeria ； Sombreiro River ； Zooplankton species