Helminths of three species of opossums (Mammalia, Didelphidae) from Mexico

Abstract

From August 2011 to November 2013, 68 opossums (8 Didelphis sp., 40 Didelphis virginiana, 15 Didelphis marsupialis, and 5 Philander opossum) were collected in 18 localities from 12 Mexican states. A total of 12,188 helminths representing 21 taxa were identified (6 trematodes, 2 cestodes, 3 acanthocephalans and 10 nematodes). Sixty-six new locality records, 9 new host records, and one species, the trematode Brachylaima didelphus, is added to the composition of the helminth fauna of the opossums in Mexico. These data, in conjunction with previous records, bring the number of taxa parasitizing the Mexican terrestrial marsupials to 41. Among these species, we recognized a group of helminths typical of didelphids in other parts of the Americas. This group is constituted by the trematode Rhopalias coronatus, the acanthocephalan Oligacanthorhynchus microcephalus and the nematodes Cruzia tentaculata, Gnathostoma turgidum, and Turgida turgida. In general, the helminth fauna of each didelphid species showed a stable taxonomic composition with respect to previously sampled sites. This situation suggests that the rate of accumulation of helminth species in the inventory of these 3 species of terrestrial marsupials in the Neotropical portion of Mexico is decreasing; however, new samplings in the Nearctic portion of this country will probably increase the richness of the helminthological inventory of this group of mammals.

ECOLOGICAL ASPECTS OF NEMATODE PARASITES OF Didelphis aurita (DIDELPHIMORPHIA, DIDELPHIDAE) IN URBAN-SYLVATIC HABITATS IN RIO DE JANEIRO, BRAZIL

“…These constitute one of the main items of the opossum diet (Santori et al 2012), causing infection by ingesting the nematode eggs or larvae. T. turgida has a heteroxenous life cycle, where the arthropods, which are present in the opossum diet, may act as intermediate hosts when infected with the nematode larvae (Anderson 2000, Jiménez et al 2011, Acosta-Virgem et al 2015. Thus, the generalist and synanthropic characteristics of the opossum may have favoured the transmission of this helminth.…”

Molecular data reveal a new species of Rhopalias Stiles & Hassall, 1898 (Digenea, Echinostomatidae) in the Common opossum, Didelphis marsupialis L. (Mammalia, Didelphidae) in the Yucatán Peninsula, Mexico

“…Rhopaliashorridus further differ from the new species, and the remaining congeners by the large number of tentacle spines (> 30) (see key in Haverkost and Gardner 2008). The new species most closely resembles the type species, R.coronatus ; in fact the specimens upon which the description of the new species is based were originally recorded as R.coronatus (see Acosta-Virgen et al 2015). Genetic data revealed that they might actually represent a different species.…”

“…According to García-Prieto et al (2012) four species of Rhopalias have been recorded in Mexico, R.baculifer and R.caballeroi in restricted localities in the tropical rain forest of Los Tuxtlas, Veracruz, and other two species more widely distributed parasitizing three species of marsupials ( P.opossum , D.virginiana and D.marsupialis ), R.coronatus , and R.macracanthus in nine and 12 localities, respectively. A few additional records were more recently provided by Acosta-Virgen et al (2015). Interestingly, in the region of Los Tuxtlas, Veracruz, where the three species of opossums are found in sympatry (see Cervantes et al 2010), the four species of Rhopalias have been recorded.…”

“…Marsupials occurring across Mexico are heavily parasitized by helminths; at least 16 helminth taxa have been recorded for D.marsupialis , 30 for D.virginiana , and 17 for P.opossum across their distributional ranges in Mexico (Acosta-Virgen et al 2015). The only study where DNA sequences were used to establish a more robust species delimitation for the helminth parasite fauna of marsupials is that of López-Caballero et al (2015).…”

“…Molecular data were used in combination with a morphological study of newly sampled specimens of R.coronatus , and those deposited at the Colección Nacional de Helmintos ( CNHE ) to describe a new species of Rhopalias . Specimens originally recorded as R.coronatus from the Yucatán Peninsula by Acosta-Virgen et al (2015) corresponded with an undescribed species. We describe the new species herein.…”