The toxicity of methanol extract of Khaya senegalensis
leaves was evaluated in
over 96 h exposure. The fish were exposed to 150 mg/L. 170 mg/L.
190mg/L, 210 mg/L and 230 mg/L of the extract and a control in acute static bioassay after a
trial finding to determine the median lethal concentration (LC50
) of the extract. Exposed fish
showed clinical signs, such a distress opercula ventilation, tail fin beats and respiratory
alteration. The frequency of opercula ventilation and tail fin beats were concentration dependent
and showed significant association (P<0.05). The LC50
value of 199,69mg/L was established for
the extract in the exposed fish where mean mortally was significantly (P<0.05) concentration
and exposure dependent. This plant is to be regarded as a piscine toxicant and should be
discarded from the bank of rivers and dams.