Mercury Content in Anguillicola crassus (Nematoda) and its Host Anguilla anguilla

Mercury content in parasite-host system (Anguillicola crassus and Anguilla anguilla) was studied in the Korycany Reservoir (Czech Republic). The swimbladder nematode contained the lowest mercury levels (0.050-0.183 mg times kg super(-1) wet weight), (p < 0.05), compared to muscles (0.162-0.827) and the liver (0.175-1.430) of the fish definitive host. The mercury concentrations in the definitive host were higher in the liver, but not significantly different from muscle concentrations. Regression analysis indicated a positive ratio between mercury concentrations in the liver and the total body length of the fish. In eels from the reservoir under study the mercury content in fish muscles exceeded the hygienic limit in one fish specimen only.