This paper assesses the role of intestinal helminth parasite of Macrobrachium vollenhovenii on host metal accumulation in Lekki lagoon, Lagos, Nigeria. Lead, zinc, copper, chromium and iron concentrations were determined in water, sediment, intestinal parasite, intestine of infected and non-infected prawns. Intestinal nematode parasite Cucullanus sp. was identified. Pb and Cr were not detected in the water and sediment. The sediment had higher concentrations of the metals than the water medium, and exceeded the WHO limits for Zn, Cu and Fe. Cucullanus sp. accumulated Zn 19 times, Cr several thousand times more and Fe 11 times more than the host intestine (wet wt). This parasite could have accumulated these metals from its host, reducing the concentration of these metals in the tissues of the infected prawns compared to non-infected ones. The infected and non-infected prawns accumulated Zn and Fe several times more than the water medium. The parasite influenced metal accumulation in the host tissue and pose ecological risk.
