Toxicological and Histopathological Effects of Parkia biglobosa Leaf Powder on Clarias gariepinus Juveniles: Implications for Aquatic Ecosystem Health

Abstract

This study seeks to determine the Toxicological and histopathological Effects of Parkiabiglobosa Leaf Powder on Clariasgariepinus Juveniles and physicochemical parameters of the cultured water. The fish were exposed to five (5) different concentrations of PLP at 0g/l (control), 15g/l, 30g/l, 45g/l and 60g/l with three replicates, with each containing ten (10) fish sample. One way analysis of variance was used to compare the mean of the different treatments, the experiment employed a completely randomized designed.  The histological examination of the liver was conducted after 96 hours using standard histological technique. Behavioural changes such as jumping, abnormal vertical orientation, air gulping, loss of buoyancy, loss of reflex and discoloration increased with increased concentration of PLP. They was a decrease in dissolved oxygen (DO) with increased concentration of Parkiabiglobosa leaf powder (PLP). The DO for the control was highest at 6.03±0.01, while the 45g and 60g of PLP has the lowest DO of 2.86±0.09 respectively. There was a decrease in Potential of Hydrogen (pH) of the cultured water with increasing concentration of PLP, the control showed the highest pH value of 7.16±0.01, followed by 15g at 6.90±0.03, while the lowest pH was recorded for 60g at 6.38±0.02. The Total Dissolved Solids (TDS) was highest at the 60g concentration of PLP (413.00±6.43). The mortality rate was higher with increasing concentration of PLP, with 100% mortality within 24 hours at the 45g and 60g. The mean toxicity level was 4.00. The L_C50 for the 96 hours was 27.55g/L.  The Biometric parameters of the varying concentration PLP throughout the 96hrs bioassay show no significant difference (p>0.05) for all parameters. Histological result of the liver of the fish exposed to PLP showed severe cellular generation, pyknotic nucleus and cellular necrosis with increased concentration of PLP, normal liver architecture was observed in the control. The PLP has negative effects on water quality, fish liver histology and on survival rate of the fish. Therefore, fish farmers should not use these plant materials as piscicide in fish harvesting in the natural water bodies as it will decrease fish populations and affect water quality which can lead to serious ecological damages.