Epiphytic algae and fauna associated with the roots of water hyacinth (Eichhonia crassipes) in Omu Creek, Lagos, Nigeria

Abstract

The epiphyton and faunal communities associated with the roots of water hyacinth (Eichhonia crassipes) in the Omu creek in Lagos, Nigeria were investigated in relation to water quality characteristics for five months at two stations (October 2012 – February 2013). The physical and chemical environments showed monthly variations linked with rainfall distribution and (brackish) water inflow from the adjoining Epe lagoon. A total of 42 organisms were identified. Thirty-three attached algal taxa and nine faunal forms especially zooplankton. The highest percentage diversity belonged to the diatoms - Division Bacillariophyta (66.67%), blue – green algae - Division Cyanophyta (9.52%), rotifers - Phylum Rotifera (9.52%), crustaceans - Phylum Crustacea (4.76%), foraminiferans - Phylum Foraminifera (2.38%), nematodes - Phylum Nematoda (2.38%) and Juvelines stages (4.76%). The dominant epiphyton species recorded were Synedra crystallina, Aulacoseira granulata var. angstissima, Fragillaria construens and Diplogasteroides sp. (nematode) for the fauna. Margalef (d), Shannon-Wiener (Hs) and Species Equitability (j) indices showed variations that were a reflection of the monthly species diversity and distribution. Low species diversity was probably due to the high floodwater flushing rates which acted as a limiting factor for attached forms.

Keywords: Epiphyton, attached animals, water quality, macrophytes, Omu creek, South- Western Nigeria