Parasitic Helminth Fauna and Heavy Metals Analysis in Macrobrachium macrobranchion (Herklots, 1851) and Macrobrachium vollenhovenii (Herklots, 1857) From Lekki Lagoon, Lagos, Nigeria.

This study was carried out to investigate  the uptake and bioaccumulation of heavy metals by intestinal helminths parasites in relation to the muscular tissues of the  freshwater prawn (Macrobrachium species) obtained from Lekki Lagoon, Epe, Lagos, Nigeria. A total of 120 specimens composed of 82 Macrobrachium macrobrachion and 38 Macrobrachium species was < 2.0.The trend of the mean metal concentration in the infected specimen ranged from Mn> Zn> Fe> Cu> Pb> Cr> Cd> Ni and Mn> Fe> Zn> Cr> Pb> Cu> Ni> Cd in the parasite.In the the non –infected specimens the trend shows; Mn > Fe> Cu> Zn> Cd> Cr, Ni> and Pb. Manganese (Mn) was found to have high concentration compared to other metal analysed .Two of the metals (Pb and Mn) were found in significantly higher concentrations vollenhovenii were examined for helminths parasites. Four species of helminths parasites were recovered; Procamallanus species, Cucullanus species, Anisakis species and Pomphorhynchus species. Out of 82 specimens of Macrobrachium macrobrachion examined, 16 (19.51%) were infected. These infected specimens had 16(19.51%) males and 0(0.00%) female while the non- infected individuals had 49 (59.76%) male and 17(20.73%) females. The Chi-square distribution was significant at 0.01 level (x²(2) =5.20, p< 0.01).Sixteen specimens (16) (42.11%) were infected out of the 38 Macrobrachium vollenhovenii examined. The infected Macrobrachium vollenhovenii had 16(42.11%) males and 0(0.00%) female and the non- infected individuals had 18(47.37%) males and 4(10.53%) females. The Chi-square distribution was significant at 0.01 level (x²(2) =5.20, p< 0.01). The condition factor in the study for Macrobrachium macrobrachion in female was 1.4±0.40 and in male 1.45±0.49, while the condition factor (K) of M. vollenhovenii in female was 1.18±0.20 and in male 1.63±0.61. The mean value for the condition factor of both in acanthocephalans compared with the host tissues. While five of the metals (Fe, Zn, Cd, Cu and Cr) were found in significant high concentration in the infected tissue than the parasites. Analysis of all the heavy metal sample recorded for the water and sediment media of Lekki lagoon, indicate Zn to be above the FME permissible limit. However, findings from this study indicate that the acanthocephalans interfere with the uptake and bioaccumulation of heavy metal in relation to the tissue of the freshwater prawn, and can be applied in biomonitoring procedure of environmental pollution.