Comparative Acute Toxicity of Aqueous Extracts of Tephrosia vogelii and Albizia gummifera on Clarias gariepinus (African Catfish) Fingerlings

Abstract

Fishing with Albizia gummifera is gaining more popularity than Tephrosia vogelii by local fishermen of Mangu Local Government Area, Plateau State and other parts of Nigeria, because of its productiveness and availability. Acute toxicity of aqueous extracts of leaf and bark of T. vogelii and A. gummifera were conducted on C. gariepinus fingerlings in static non-renewable bioassay. Dissolved Oxygen (DO) mg/L, pH and Temperature (°C) were monitored daily throughout the period by using ExStik® DO600 meter. Definitive acute concentrations of 140, 120, 100, 80, 60, 0.00 mg/L; and 600, 525, 454, 375, 225 and 0.00 g/L as control of aqueous bark and leaf extracts in mg/L for A. gummifera and T. vogelii were used respectively. The result of the water quality parameters of fishes exposed to various plant toxicant concentrations of the plants showed no variation in all the studied water parameters compared with the control treatments. The percentage mortality of fishes was observed to decrease with decrease in toxicant concentrations in both plants. The 96hrs LC10; LC50 and LC99 values with confidence limits were of 61.21 (53.54 - 104.67) mg/L and 131.86 (104.67 - 166.10) mg/L; 94.58 mg/L (108.56 - 82.419) and 277.82 (220.54 - 349.98); and 208.46 (182.31 - 238.35) and 1074.73 (853.13 - 1353.82) of aqueous bark and leaf extracts of A. gummifera and T. vogelii to the exposed fishes, respectively. Lower lethal concentration values of A. gummifera indicated that it is more toxic than T. vogelii. Therefore, fishing with the A. gummifera should be regulated in order to preserve fish species in wild.