First Report of Oligacanthorhynchus microcephalus (Rudolphi, 1819) (Acanthocephala: Oligacanthorhynchidae) in Didelphis albiventris (Lund, 1841) (Marsupialia: Didelphidae) in Southeastern Brazil

Abstract

Although acanthocephalan parasites were discovered many decades ago, very little is known about their epidemiology, biology, pathogenicity and economic impact. Didelphids (opossums) are primitive animals with opportunistic and synanthropic habits, which have a predisposition to infectious endoparasites due to their omnivorous eating habits. Two female specimens of Didelphis albiventris were necropsied at the Wild Animal Screening Center (CETAS) of the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) in the Municipality of Juiz de Fora, state of Minas Gerais, Brazil. The macroscopic analysis revealed the presence of a single acanthocephalan worm, 150.0mm long and 7.0mm wide, 98.0mm long and 4.0mm wide, in the small intestine of each opossum. A parasitological analysis showed that the worms had white, pleated, fusiform, spiral-shaped bodies with marked transverse wrinkles, a proboscis broadly armed with six longitudinally arranged spiral rows of six shallowly rooted hooks each, making a total of 36 hooks, all features compatible with Oligacanthorhynchus microcephalus. To the best of our knowledge, this paper offers the first report of natural infection of D. Albiventris by O. Microcephalus in the state of Minas Gerais, in southeastern Brazil. However, new studies of the helminthic fauna of marsupials are needed in order to further elucidate aspects pertaining to the biological behavior of the parasites, and to estimate the prevalence and impact of these infections in the wild.