Abstract

Anigboro Bright Festus

Acute and sub-acute toxicities of five plants’(Almond – Terminalia catappa, Pawpaw – Carica papaya, Neem – Azadirachta indica, Tobacco – Nicotiana tobacum and Cassava – Manihot esculenta) extracts on O. niloticus were conducted for 28 days to evaluate LC50s, fish behavior and heamatological indices of white tilapia in glass aquaria tanks. While the acute test lasted 48 hours, the sub-acute test lasted 28 days. The concentrations used for acute test were Almond = 15, 2.0, 2.5, 3.5 g/l, Cassava = 0.5, 1.0, 1.5, 2.5 g/l, Neem = 0.5, 1.5, 2.0, 2.5 g/l, Pawpaw = 1.0, 2.0, 3.0, 4.0 g/l, Tobacco = 0.25, 0.5, 1.5, 2.5 g/l and a control (0.0 g/l), while those used for subacute tests were Almond= 0.5, 0.7, 0.9, 1.0 g/l, Cassava = 0.15, 0.2, 0.35, 0.45 g/l, Neem = 0.10, 0.20, 0.35, 0.50 g/l, Pawpaw = 0.3, 0.5, 0.7, 1.0 g/l, Tobacco = 0.10, 0.15, 0.20, 0.25 g/l and a control (0.0 g/l). The mean values for the 48-h LC50s of the different plants’ concentrations on O. niloticus were 0.83 g/l, N. tobaccum, 1.22 g/l M. esculenta, 1.64 g/l A. indica, 2.16 g/l C. papaya and 2.44 g/l T. catappa logarithmically. There were significant differences (P0.05) among the treatments. Also, fish became anaemic and stressful in the exposed plant botanicals and the severity was directly proportional to the active doses of each plant concentrations. The overall results showed the potency of the five botanicals in the order of tobacco>cassava>neem>pawpaw>almond.