Description of the helminth communities of sympatric rodents (Muroidea: Cricetidae) from the Atlantic Forest in northeastern Argentina

Abstract

Taxonomic and ecological aspects of the helminths found in the assemblage of sigmodontine rodents (Cricetidae-Muroidea) of the Atlantic Forest in Argentina are studied in this paper. The following species Akodon montensis, Brucepattersonius sp. and Thaptomys nigrita (Tribe Akodontini), as well as, Euryoryzomys russatus, Nectomys squamipes, Oligoryzomys nigripes, and Sooretamys angouya (Tribe Oryzomyini) are analyzed. A complete taxonomic list with a total of 25 species of helminths, including Digenea (Dicrocoeliidae), Cestoda (Hymenolepididae) and Nematoda (Trichuridae, Capillariidae, Cooperidae, Helligmonellidae, Oxyuridae, and Onchocercidae) is provided. Twenty new host and locality records for Misiones, Argentina, are reported and the results of the ecological descriptors of component communities are given. The highest value of richness was observed for A. montensis (S=8) and E. russatus (S=7). The diversity index (H´) reached values between 1.03 and 1.39 in all rodents, with the exception of N. squamipes that reached 0.75. The equitability indeces with highest value were observed for T. nigrita and E. russatus. The Berger-Parker index of dominance was similar for all host species. The highest prevalence, mean abundance and mean intensity values corresponded to Nippostrongylinae, followed by Syphacinii. This survey constitutes the report with the most diverse parasitic assemblage of rodents described for the Atlantic Forest ecoregion and for Argentina.

Helminth metacommunity structure of wild rodents in a preserved area of the Atlantic Forest, Southeast Brazil

“…The highest total helminth species richness in A. montensis (six) in comparison with other rodents corroborates the results from other surveys which also found greater richness in this host (PÜTTKER et al, 2008;PANISSE et al, 2017). However, the total helminth species richness found for this rodent was lower than those reported in other studies; Püttker et al (2008) observed seven morphotypes in a study in the State of São Paulo, Brazil; Panisse et al (2017) reported eight helminth species for this rodent in Misiones Province, Argentina. In a previous study carried out in a different locality in PARNASO (Teresópolis) and in forest fragments on its surroundings, Simões et al (2011) reported twelve helminth species in A. montensis, considering 13 localities.…”

“…These authors reported the occurrence of a new species of the genus Stilestrongylus in Argentina. In the present study, the only specimen of Stilestrongylus found in T. nigrita seems to be the same species that was found by Panisse et al (2017) based on the morphological characteristic observed. However, the authors did not provide further information.…”

“…Considering the helminth fauna of A. montensis, all helminth species found in the present study were previously reported (MALDONADO Jr. et al, 2010;SIMÕES et al, 2011;PANISSE et al, 2017). Other genera and species already registered for this host include Angiostrongylus lenzii, S. lanfrediae, Syphacia carlitosi, Litomosoides silvai, Trichuris sp., Echinostoma luisreyi in Brazil (SIMÕES et al, 2011;GRESSLER et al, 2017), Eucoleus sp., Platynosomoides sp., Tapironema coronatum and Trichuris navonae in Argentina (ROBLES, 2011;PANISSE et al, 2017).…”

“…For the rodent O. nigripes, the helminths S. lanfrediae and G. zetta were already registered in this host (SOUZA et al, 2009;SIMÕES et al, 2011;WERK et al, 2016;PANISSE et al, 2017 PANISSE et al, 2017) and Trichuris travassosi in the State of Rio Grande do Sul, Brazil (GOMES et al, 1992).…”

“…Litomosoides nasuti was recorded in Oxymycterus nasutus in Uruguay ). In addition to these helminth species, Navone et al (2009) The helminth fauna of T. nigrita was previoulsy described by Panisse et al (2017). These authors reported the occurrence of a new species of the genus Stilestrongylus in Argentina.…”