ACUTE TOXICITY OF AQUEOUS CRUDE STEM BARK OF ERYTHROPHLEUM SUAVEOLENS EXTRACT ON THE BEHAVIOURAL AND BLOOD BIOCHEMISTRY OF CLARIAS GARIEPINUS JUVENILES

The unusual use of Erythrophelum suaveolens aqueous crude stem bark extract by fishermen has led to a decline in the number of fish catch which causes effects on the economy of the fishermen and the community in general. The aim of this study is to determines the toxic effects of aqueous crude stem bark extract of E. suaveolens on Clarias gariepinus juveniles by assessing the phytochemicals, investigation of changes in water quality parameters and biochemical parameters. Total of 120 mixed sex juveniles of C. gariepinus (mean weight 21.3g and mean length 14.5cm) were used for the experiment. Acute toxicity test (96 hrs static non reneweable bioassay) was carried out with ten (10) fish in each of the six (6) circular tanks, each duplicate replicated. After a range finding test was conducted, fish were exposed to various concentrations of 1.00, 1.50, 2.00, 3.00, 4.00 and 0.00g/L served as the control. Fish exposed to the graded concentrations show abnormal behaviours and mortalities increased as the toxicant concentrations increased throughout the exposure period i.e the highest concentration of 4.0g/L recorded the highest mortality of 100% while the lowest mortality of 20% was recorded in the lowest concentrations of 1.0g/L aqueous crude stem bark extract of E. suaveolens. However, no mortality was recorded in the control tank (0.00g/L). The 96hr LC50 of experimental fish exposed to aqueous crude stem bark extract of E. suaveolens was determined graphically to be 2g/L with the upper and lower confidence limits of 2.2 and 1.8 respectively. The result of the phytochemical screening of the toxicant showed the presence of saponins, tannins, phenol, alkaloids, Flavonoids, cardiac glycosides, carbohydrates and steroid. The result of the water quality parameter monitored during the experiment varied significantly (P>0.05) in Dissolved oxygen and Free carbondioxide, while Alkalinity, pH, and temperature were not significantly different (P0.05), the activities of the Aspertate aminotransferase, Alanine transaminase and Alkaline phosphatase, The acute bioassay of aqueous crude stem bark extract of E. suaveolens on C. gariepinus juveniles revealed that the substance is toxic to the exposed fish at graded concentrations and the result showed the 96 hrs LC50 caused 50% mortality. The toxicant had adverse effects on the water qualities, behavioural signs, and biochemical parameters of the exposed fish compared to the control groups. Therefore, the use of E. suaveolens in water bodies could lead to contamination of aquatic ecosystem by causing alteration in the physiological and general health of fish and other aquatic fauna.