Authors : Samson Eneojo Abalaka, Muhamad Yakassai Fatihu, Najume Doguwar Gingiya Ibrahim and Suleiman Folorunsho Ambali
Abstract: The possible use of ethanol extract of Adenium obesum stem bark as a potent organic piscicide, against unwanted predatory animals and/or fish in fish ponds prior to the stocking of the desired fish was investigated via the exposure of the hardy air-breathing Clarias gariepinus to the extract over a 96 h exposure period. Clarias gariepinus of 265.50±4.03 g mean weight and 32.85±0.16 cm mean total length were exposed to 0.00, 6.25, 7.50, 8.20, 8.80 and 9.30 mg L-1 of the extract in a static acute toxicity bioassay after performing a range finding test. The extract contained some toxicologically bio-active substances. Changes in the fish culture water quality were within acceptable limits. The exposed fish showed signs of restlessness and hyperactivity along with signs of respiratory and nervous compromise, as well as the observed mortality in some of the exposed fish whose appearance and intensity were concentrations and exposure period-dependent. However, no signs of toxicity were observed in the unexposed control fish. The median lethal concentration of the extract in the exposed fish over the 96 h exposure period was 7.15 mg L-1. Therefore, at this or much higher concentrations, the extract will be a potent organic piscicide that can be used to eradicate unwanted predatory animals, especially fish from ponds prior to the stocking of desired fish.
Samson Eneojo Abalaka, Muhamad Yakassai Fatihu, Najume Doguwar Gingiya Ibrahim and Suleiman Folorunsho Ambali, 2013. Exploitation of Ethanol Extract of Adenium obesum Stem Bark as a Potent Organic Piscicide. Research Journal of Biological Sciences, 8: 143-149.