PLANKTON COMPOSITION AND GUT CONTENT OF Coptodon zilli (GERVAIS, 1848) AND Clarias agboyiensis (SYDENHAM, 1980) IN AWARA RESERVOIR, IKARE AKOKO, ONDO STATE

Abstract

Plankton composition and gut content of Coptodon zilli and Clarias agboyiensis in Awara Reservoir, Ikare Akoko Ondo state were investigated from January to June, 2019.Plankton and fish samples were collected from January to June 2019. Plankton were collected using plankton net of about 600μm mesh size emptied into sampling bottles, preserved, examined with binocular microscope and identified using standard guides. Fish species were collected using gillnet of about 16 mm mesh size and preserved in 10% formalin after identified. The order of plankton abundance was; Pseudo-nitzschia australis> Cyclotella striata>Cyclotella comta>Vorticella spp>Rhizosolenia hebetate >Desmidium spp> Prorocentrum micans>Protoperidinium diabolum >Dipleuchlanis propatula>Stenelmis crenata >Navicula Closterium> Zygnema spp, Pediastrum spp and Trichocerca capucina. The Shannon-Wiener index ranged from 0.69 to 1.77, Dominance 0.24 to 0.50, Menhinick index 1.29 to 2.11, Margalef’s diversity index 1.44 to 2.67, Simpson’s index of diversity 0.50 to 0.76, Berger-Parker index 0.38 to 0.67 while Pielou’s measure of evenness ranged from 0.67 to 1.00. Numerical method and Frequency of occurrence were used in this study. Data collected showed that C. zilli is herbivorous fish and its gut content include Diatoms, Charophyta, Ciliophora, Miozoa, Dinoflagellata, Chlorophyta while C. agboyiensis is an omnivorous fish and its gut content include diatoms, Crustaceans, plant seed, Charophyta, rotifers, Wood particles, Insect and Sand grains. The mean total length, standard length and weight of C. zilli were 18.62±6.12, 15.21±5.03and 77.23±24.16 respectively while the mean total length, standard length and weight of C. agboyiensis were 25.25±7.11, 25.06±8.11 and119.89±29.05 respectively. The LWR for C. zilli indicated negative allometric growth pattern while C. agboyiensis indicated positive allometric growth. The condition factor (K) of both species indicated that the study area has a good ecological condition. The stability and security of aquatic ecosystems can be maintained by protecting and conserving the diversity of plankton in the area.