In the body biomass of Anguillicola crassus, males and females, five microe
lements (Fe, Zn, Mn, Cu, Co) were determined by the atomic absorption spect
rometry. In the mean content values of individual elements, significant qua
ntitative differences between both sexes of the swimbladder nematode were f
ound. These differences were well related with the hematophagy of the paras
ite males and females.