Taxonomia e morfologia de protozoários ciliados (Listostomatea, Trichostomatia) endossimbiontes de ruminantes domésticos no Brasil

Abstract

This study is about taxonomy and morphology of endosymbiotic ciliated protozoa (Litostomatea, Trichostomatia) of Brazilian domestic ruminants. The work is divided into four sections. Section 1 reviews the main methods in microscopy and molecular biology used in the taxonomic study of rumen ciliates. Section 2 presents an inventory of species of ciliated protozoa Brazilian sheep, which were inventoried 28 species of ciliates, and, Entodinium alces, Metadinium esalqum and Metadinium rotundatum were first observed in sheep and other 12 species were first observed in Brazilian sheep. Still, the session shows the redescription of Entodinium contractum Kofoid & Christenson (Entodiniomorphida, Ophryosocolecidae) based on general morphology and description of oral infraciliature; Section 3 is the morphological characterization of a polymorphic species of ophryoscolecid ciliate Diplodinium anisacanhum da Cunha and a brief taxonomic revision of the genus Diplodinium Schuberg. The morphological and morphometric characterization of D. anisacanthum showed great similiarities among morphotypes suggesting that such ciliates constitute a single species endowed with polymorphism. A brief review conducted highlights the inconsistencies in the taxonomy of the genus Diplodinium and demonstrates the need for recent studies with representatives of the genus in order to improve the taxonomy of it. Finally, Section 4 describes a new species of ophryoscolecid ciliate Diploplastron dehorityi and redescribe the species Diploplastron affine (Dogiel & Fedorowa) based on morphological and morphometric characterization and details of oral infraciliature. The new species differs in some aspects of the species D. affine. The skeletal plates in D. dehorityi are not juxtaposed and have curved shape. Still, the new species has the oval body, differing from the elliptical body of D. affine. In addition to the similarities between the new species and congener species, D. dehorityi has great morphological similarity to species of the genus Eremoplastron, differing only in the number of skeletal plates.