Parasites of crayfish ( P. clarki ) and lobsters ( Macrobrachium vollenhovenic ) as indicators of metallic pollution in great, Kwa river, Nigeria

Studies on parasites of crayfish and lobsters as indicators of metal pollution in Great Kwa River, Nigeria was evaluated using appropriate instruments for determination of Physicochemical parameters and detection of metals. Formol ether centrifugation method was used for isolation of parasites. A total of 150 crayfish and lobsters were analyzed for metals and tested for parasites. All samples of crayfish (100%) and 136 (90.66%) lobsters were positive with parasites. The distribution of parasitic infection in crayfish from the 5 sampling zones showed Paragonfmus uterobilateralis prevalence 6.0%, 8.7%, 15.3%, and 10.0% from zones 1-4 respectively and crayfish leech prevalence of 10.3%, 16.0% and 20.0% from zones 3-5 respectively. The distribution of parasites in Lobsters showed  Polymorphus botulus , 3.3%, 6.0%, 3.6%, and 8.7% prevalence from zones 1-4 respectively. Nicothoic astaci , prevalence was 2.0%, 15.3% and 5.0% from zones 2-4 respectively. Prevalence of Hysterothylacium sp of 2.0% was observed in zone 3 while that of Porospora gigantic was 3.7% in zone 5. Parasite intensity ranged from 2 to 6. Metals detected included Lead (Pb). Copper (Cu), Iron (Fe), Cadmium (Cd), Asenium (As) and Zinc (Zn) with Iron being the commonest. Some parasites with high prevalence in zones where certain metals had high concentration were detected. These parasites can be used as indicators of pollution in the study area. KEYWORDS : Physicochemical, detected, pollution, concentration, indicator and prevalence.