The element manganese in parasitic helminths–A preliminary note

The distribution of manganese in parasitic helminths belonging to the trematodes, cestodes or nematodes was analysed by the use of an atomic absorption spectrophotometer. The results of these analyses have demonstrated that growing trematodes (smaller forms) with active oogenesis and spermatogenesis contained more manganese than older forms (large or very old adults) with empty uteri and large lobulated testes. In cestodes, the neck region of cysticerci and immature proglottids showed more manganese concentration than the mature and gravid proglottids of worms or cyst proper. Similarly, the youngest endogenous daughter cysts of Echinococcus granulosus showed more manganese in their walls than those of larger forms. The element was found more concentrated in nematode eggs than in adult females. The significance of this element in parasitic helminths—both adult and larval stages is briefly discussed.