HAEMATOLOGICAL CHANGES IN NICKEL EXPOSED NILE TILAPIA OREOCHROMIS NILOTICUS DURING EXPOSURE AND RECOVERY PERIODS

BIOCHEMICAL IMPACT OF NICKEL ON TILAPIA

Abstract

Fresh water environment is impacted by enduring pollution, caused by both natural factors and anthropogenic activities such as industrialization, urbanisation, agriculture activities and mining. Heavy metals are a major problem concern as they are toxic and tend to accumulate and impose their effect on circulation system of fish. The present investigation was carried out to evaluate the lethality of Nickel chloride on fingerlings of Nile tilapia, Oreochromis niloticus. The effect of Nickel chloride on fish haematology was assessed on the basis of the impact of long term exposure to below safe concentrations(1/5th (9.39 ppm) and 1/10th (4.69 ppm)for a period of 28 days with 7 days interval sampling. Haematological recovery(depuration of Nickel chloride)was also studied by maintaining the exposed fish in a well aerated, good fresh water for an additional 28 days with 7 days interval sampling. The haematological analysis showed significantly reduction in red blood cell (RBC's) count, haemoglobin (Hb), Haematocrit (Hct), Mean Cell Haemoglobin Concentration (MCHC)values, while white blood cells(WBC's) count, Mean Cell Volume (MCV), Mean Cell Haemoglobin (MCH) were increased in Nile tilapia. During accumulation phase. The limited recovery was obtained in all the haematological parameters after depuration for 28 days from the end of accumulation period. The informations generated would be utilised as bioindicators for the aquatic pollutions specifically Nickel pollution.