Incidência de parasitas do Phylum Myxozoa (sub-reino protozoa) em peixes da região amazônica, com especial destaque para o gênero Henneguya.

Abstract

This paper discusses the importance of some species of the myxozoan genus Henneguya Thelohan, 1892 as icthyoparasites of Amazon fishes. These parasites are a heterogeneous group affecting various tissues, causing great damage and in some cases the death of their hosts. They have been found in different geographic areas and described in hosts of diverse taxonomic groups. Spores of Henneguya are formed by two valves, each with a long tail. Two capsulogenic cells and a binuclear sporogenic cell are found in their interior. Five Henneguya species found in Amazon fishes near Belém (State of Pará, Brazil) include H. amazonica, H. striolata, H. malabarica, H. adherens and H. testicularis. Their ultrastructural morphology as well as of the two other myxosporids, Myxobolus braziliensis and Tetrauronema desaequalis, are described. Parasitism over the host tissue and host reaction is also discussed.