TOXICITY OF LOCUST BEAN (Parkia biglobosa) INDUSTRY EFFLUENTS TO TILAPIA (Tilapia zillii (Gervais, 1848) JUVENILES AND THE EFFECTS ON SOME TARGET ORGANS

Abstract

This study was carried to determine the toxicity of locust bean (Parkia biglobosa) industry effluents to Nile tilapia juveniles and the effects on some target organs. One hundred and fifty healthy tilapia juveniles were used for the experiment, 120 were exposed to locust bean effluents (100, 110, 120 and 130 ml /10 L) in triplicate for 96 hours. Indices such as water quality parameters (pH, DO2, Conductivity, Temperature), histological examinations (gills and liver), haematological parameters (Haemoglobin, Red Blood Cell, White Blood Cell, Mean Corpuscular Volume, Parked Cell Volume, Mean Corpuscular Haemoglobin, Mean Cell Haemoglobin Concentration), behavioural responses and LC50 were observed/determined and recorded. The results showed that Parkia biglobosa have negative impact on the observed indices as the concentration increased. pH, DO, conductivity and temperature of the treated groups differed from the control (p>0.05). Histological examination of the gills showed slight detachment of epithelial cell, increased detachment of epithelium and lamella slightly visible, alteration of primary filament and lamella was not visible to total erosion of lamellae of gill filament, liver changes include loss of hepatocytes, disarrangement of cells, vacuolation and necrosis. The study showed that locust bean waste water (LBPWW) is toxic to T. zillii. The histological and haematological examination revealed that locust bean waste water had negative effects on the tissues (blood, gills and liver) of the Tilapia juveniles.