Invertebrate fauna associated with water hyacinth (Eichhornia crassipes) in Benin River, southern Nigeria

The invertebrate fauna associated with water hyacinth (Eichhornia crassipes) in Benin River was studied between February and August, 1990. Water hyacinth along with water samples was collected for analysis. The range of water temperature was 26.0–32.2oC, dissolved oxygen (D.O) was 1.60–14.98 mgl-1 and salinity was 0.42-6.84o/oo. Twenty-two (22) species of organisms attached to the roots of the plant were recognized. Gastropods, which made up 41.24% of the total faunal population, were the most abundant, while the annelids were the least, numerically making up only 0.08% of the faunal population. Colonisation of the roots of water hyacinth, was multiple factor dependent. Tropical Freshwater Biology VOL. 8 1999, pp. 31-40 KEY WORDS: nutrients - macrophytes - estuary - brackish water - freshwater - fauna