Topic
Scapteromys
About: Scapteromys is a research topic. Over the lifetime, 10 publications have been published within this topic receiving 172 citations.
Papers
TL;DR: The taxonomic status of A. dubitatum along its distribution appears to be certain at the specific level, because environmental variables rather than hosts determine the distributional ranges of this tick.
Abstract: We supply information about hosts and distribution of Amblyomma dubitatum. In addition, we carry out an analysis of genetic divergence among specimens of A. dubitatum from different localities and with respect to other Neotropical Amblyomma species, using sequences of 16S rDNA gene. Although specimens of A. dubitatum were collected on several mammal species as cattle horse, Tapirus terrestris, Mazama gouazoubira, Tayassu pecari, Sus scrofa, Cerdocyon thous, Myocastor coypus, Allouata caraya, Glossophaga soricina and man, most records of immature and adult stages of A. dubitatum were made on Hydrochoerus hydrochaeris, making this rodent the principal host for all parasitic stages of this ticks. Cricetidae rodents (Lundomys molitor, Scapteromys tumidus), opossums (Didelphis albiventris) and vizcacha (Lagostomus maximus) also were recorded as hosts for immature stages. All findings of A. dubitatum correspond to localities of Argentina, Brazil, Paraguay and Uruguay, and they were concentrated in the Biogeographical provinces of Pampa, Chaco, Cerrado, Brazilian Atlantic Forest, Parana Forest and Araucaria angustifolia Forest. The distribution of A. dubitatum is narrower than that of its principal host, therefore environmental variables rather than hosts determine the distributional ranges of this tick. The intraspecific genetic divergence among 16S rDNA sequences of A. dubitatum ticks collected in different localities from Argentina, Brazil and Uruguay was in all cases lower than 0.8%, whereas the differences with the remaining Amblyomma species included in the analysis were always bigger than 6.8%. Thus, the taxonomic status of A. dubitatum along its distribution appears to be certain at the specific level.
84 citations
TL;DR: It is proposed that S. aquaticus be elevated to the rank of species, the known distributions of S. tumidus are redefined, and a list of character states that allow an unambiguously diagnosis of both species are provided.
Abstract: We present a systematic study of Scapteromys populations from Argentina, Paraguay, and Uruguay, based on molecular and morphological evidence. First, based on DNA sequences (801 base pairs) from the mitochondrial cytochrome-b gene, we found that Scapteromys populations fall into 2 main clades; 1 formed by Argentinean and Paraguayan populations together with 1 population from western Uruguay, and the other constituted by the remaining Uruguayan populations. Analysis of molecular variance showed that 86.93% of the genetic variation uncovered in Scapteromys is explained by differences between clades. Morphological analyses corroborated the existence of 2 main morphotypes among Scapteromys specimens. The phylogeographic break identified is mostly congruent with patterns of morphological and chromosomic variation. In light of these results, we propose that S. aquaticus be elevated to the rank of species, we redefine the known distributions of S. aquaticus and S. tumidus, and we provide a list of character states that allow an unambiguously diagnosis of both species.
62 citations
TL;DR: Both larvae and nymphs were found on hosts during all seasons of the year, with a higher prevalence in summer, and DNA analysis may confirm their conspecificity.
Abstract: Specimens of Ixodes longiscutatus Boero, 1944 (Ixodidae) were collected in Uruguay and, to a lesser extent, Argentina from 1998 to 2004. Specimen data and literature records were used to compile a comprehensive list of hosts and to define the ecological parameters of this tick species, which is currently known from a total of only 6 females, 37 nymphs and 94 larvae. The male remains undescribed. Bona fide records of females were from cattle, horse, Cavia tschudii Fitzinger, 1857 and Cavia sp. (Rodentia: Caviidae). Most nymphs were collected on rodents of the family Cricetidae, especially Oxymycterus nasutus (Waterhouse, 1837) and Scapteromys tumidus (Waterhouse, 1837), but also C. tschudii. Again, most larvae were found on cricetid rodents, namely O. nasutus, S. tumidus, Akodon lutescens Allen, 1901, Oligoryzomys flavescens (Waterhouse, 1837) and Necromys obscurus (Waterhouse, 1837), and on Caviidae (Cavia aperea Erxleben, 1777 and C. tschudii). Both larvae and nymphs were found on hosts during a...
9 citations
TL;DR: By G- band comparisons it is found that the 2n = 24 S. tumidus from Uruguay and Brazil are chromosomically more closely related to S. aquaticus from Argentina than to alleged S. baptis from Argentina, suggesting that the latter may represent a new, still undescribed, species.
Abstract: SUMMARYSouth American rodents of the genus Scapteromys, are know to exist in a number of different chromosomal forms. S. tumidus has 2n = 24 from Uruguay while three different Brazilian taxa, all referred to as S. tumidus have respectively 2n = 36,34 and 24. S. aquaticus from Argentina has 2n–32. By G- band comparisons we find that the 2n = 24 S. tumidus from Uruguay and Brazil are chromosomically more closely related to S. aquaticus from Argentina than to alleged S. tumidus with 2n = 34–36 from Brazil. These results suggest that the latter may represent a new, still undescribed, species.
8 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 1 |
| 2016 | 1 |
| 2013 | 2 |
| 2010 | 1 |
| 2004 | 1 |