Piscicidal Effects of Aqueous Leaf Extract of Calotropis procera on Clarias gariepinus Fingerlings
1Odulate, D. O., 2A. O. Agbon, 3S. O. Ajagbe, 1W. O. Abdul, and 3S. A. Abdulsalami
1Department of Aquaculture and Fisheries Management, Federal University of Agriculture,
Abeokuta, P.M.B. 2240, Abeokuta, Ogun State, Nigeria.
2Department of Animal and Environmental Biology, Federal University Oye-Ekiti,
P.M.B. 373, Oye, Ekiti State, Nigeria.
3Fisheries and Aquaculture Management Unit, Department of Biological Sciences, Crescent
University, P.M.B. 2082, Abeokuta, Ogun State, Nigeria
The presence of unwanted predatory fish in newly stocked fish ponds constitute a nuisance and also compete with fingerlings for food in earthen ponds. An ichthyotoxin of plant origin, aqueous extract of Calotropis procera (Common name: Apple of Sodom) was tested on Clarias gariepinus fingerlings to evaluate its potential use in the eradication of unwanted fish from culture systems. The experiment with concentrations of 0 (control), 10, 20, 40 and 80 mg/L was carried out using static renewal bioassay techniques in transparent glass tanks in triplicates. Data on temperature, pH, dissolved oxygen (DO), conductivity and total dissolved solids (TDS) were collected and analyzed. Probit analysis was used to determine median lethal concentration (LC50). The 48-hr LC50 obtained was 35.76 ml/L. The 95% confidence limit of 48-hr LC50 was found to be 25.708 ml/L for lower limit and 51.140 ml/L for upper limit. The study showed that leaf extract of C. procera can be used to clear fish ponds before stocking. It is recommended for use because it is natural, biodegradable and does not persist in the environment.