अमूर्त

ACANTHOCEPHALA AND ITS RELATIONSHIP WITH HELMINTHES AND ROTIFERS: A REVIEW

Monika Panchani*

Many parasitic forms of helminthes inhabit the different animal hosts. Most of them are placed in classes Platyhelminthes, Cestodes and Nematodes. There are some other parasitic forms which show resemblances with helminthes but are placed in different phylum. One of the groups of parasitic worms belongs to phylum Acanthocephala. These are thorny-headed or spiny-headed worms, characterized by the presence of an eversible proboscis armed with spines. Phylum Acanthocephala includes large number of parasitic worms inhabiting the intestine of different vertebrates ranging from fish to mammals. They live as adults in the intestine of vertebrates and as larvae in arthropods. The most typical forms are Acanthocephalus, Neoechinorhynchus and Gigantorhynchus. Earlier the Acanthocephala were thought to be a discrete phylum but recent genome analysis has shown that they are descended from rotifers. This unified taxon is known as Syndermata. As Acanthocephalans share characters with Helminths and with Rotifers, so they are potential model system from the point of evolution of parasitism. In this paper the general characters and life cycle and evolution of Acanthocephalan were studied and its relationship with Cestodes, Nematodes and Rotifers were reviewed.