RESUMO
Octodontids are South American caviomorph rodents endemic to mesic and arid biomes displaying a wide range of substrate preferences, from terrestrial to subterranean habits. However, the hind limb morphology of these rodents remain relatively poorly understudied, particularly from an ecomorphological perspective. To investigate the association between hind limb morphology and substrate preference-epigean, semifossorial, fossorial, and subterranean- this study analyzed six skeletal measurements of femur and tibia, along with five morphological indices. We employed phylogenetic mapping, allometry, and multivariate analyses (Phylogentic Flexible Discriminant and Principal Component analyses) on log-transformed variables and indices. The results suggest that the epigeans and subterraneans possess hind limb skeletal features that enhance their mechanical capabilities, which are advantageous for their respective lifestyles. However, in the absence of clear behavioral adaptations or associations, the functional habits of Octodontidae do not requires significant structural modifications of the proximal bones of the hind limbs. These results indicate that understanding the form-function relationship in octodontids requires direct field or laboratory observations of behavior and environmental interactions, highlighting the limitations of current research without such data.
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We applied a step-down factor analysis (SDFA) and multi-site generalised dissimilarity modelling (MS-GDM) to local flea communities harboured by small mammals (i.e., collected at small sampling sites over a short time period) in two South American regions (Patagonia and the Northwestern Argentina) with the aim of understanding whether these communities were assembled via niche-based or dispersal-based processes. The SDFA allows us to determine whether clusters of flea assemblages across different types of climates, vegetation and soils can be distinguished (suggesting niche-based assembly). MS-GDM allows us to determine whether a substantial proportion of the variation in flea species turnover is explained by specific climate-associated, vegetation-associated and soil-associated variables (indicating niche-based assembly) or host turnover (indicating dispersal-based assembly). Mapping of assemblages on climate, vegetation and soil maps, according to their loadings on axis 1 or axis 2 of the SDFA, did not provide clear-cut results. Clusters of similar loadings could be recognized within some, but not other, climate, vegetation and soil types. However, MS-GDM demonstrated that the effect of environmental variables (especially air temperature) on flea compositional turnover was much stronger than that of host turnover, indicating the predominance of niche-based processes in local community assembly. A comparison of our results with those on the mechanisms that drive species assembly in regional communities allows us to conclude that local and regional communities result from the joint action of niche-based and dispersal-based processes, with the former more important at a smaller spatial scale and the latter at a larger spatial scale.
Assuntos
Sifonápteros , Animais , Mamíferos , Solo , Clima Tropical , Argentina , Ecossistema , BiodiversidadeRESUMO
The common vampire bat (Desmodus rotundus) is a sanguivorous (i.e., blood-eating) bat species distributed in the Americas from northern Mexico southwards to central Chile and Argentina. Desmodus rotundus is one of only three mammal species known to feed exclusively on blood, mainly from domestic mammals, although large wildlife and occasionally humans can also serve as a food source. Blood feeding makes D. rotundus an effective transmissor of pathogens to its prey. Consequently, this species is a common target of culling efforts by various individuals and organizations. Nevertheless, little is known about the historical distribution of D. rotundus. Detailed occurrence data are critical for the accurate assessment of past and current distributions of D. rotundus as part of ecological, biogeographical, and epidemiological research. This article presents a dataset of D. rotundus historical occurrence reports, including >39,000 locality reports across the Americas to facilitate the development of spatiotemporal studies of the species. Data are available at https://doi.org/10.6084/m9.figshare.15025296 .
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Quirópteros , Animais , Argentina , Humanos , México , Estados UnidosRESUMO
Alectopsylla unisetosa (Ischnopsyllidae) from Santa Cruz province represents the second report of the species after 45 years. This new distributional record extends this species distribution 1350 km further south than previously documented. Moreover, Alectopsylla unisetosa infesting Myotis chiloensis constitutes a new flea-host association. This finding provides new insights into the biogeography and host associations within the family Ischnopsyllidae.
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Distribuição Animal , Quirópteros/parasitologia , Interações Hospedeiro-Parasita , Sifonápteros/anatomia & histologia , Animais , Feminino , MasculinoRESUMO
Rodents of the family Octodontidae, endemic to South America, represent a group with low taxonomic richness group (six genera and 14 species) but have great ecomorphological diversity with epigean, semi-fossorial, fossorial, and subterranean forms. We analyzed morphometric variation in humerus and ulna, the possible relationship with substrate preference use, and the presence of a phylogenetic signal in the forelimbs traits (five biomechanical indices). Our results show that, in octodontids, the forelimb variation was not primarily associated with their phylogeny and some attributes are highly explanatory in terms of function, with a clear differentiation between the substrate use gradient extremes (i.e. epigean and subterranean forms). The two forelimb traits, the development of humeral epicondyles and the olecranon process of the ulna, indicative of adaptive trends found in Octodontidae are consistent with most of those described for other mammals and corroborate the relevance of forelimb characters to differentiate modes of locomotion or substrate preferences.
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Comportamento Animal , Membro Anterior/anatomia & histologia , Roedores/anatomia & histologia , Roedores/fisiologia , Animais , Ecossistema , Análise Multivariada , Filogenia , Roedores/genéticaRESUMO
In few groups of parasites have the patterns of distribution been studied using quantitative methods, even though, the study of these organisms indirectly provides information on the biogeographic history of their hosts, and in turn, the history of the hosts allows elucidation of speciation events of the parasites. Our objective was to quantitatively identify distributional congruence patterns of native fleas in northwestern Argentina. We analyzed 159 georeferenced distributional records of 47 species and six subspecies of fleas in northwestern Argentina using NDM/VNDM software. We found eight consensus areas, defined by 17 species and two subspecies, included in six patterns of distributional congruence (PDCs) with endemic and non-endemic fleas. The PDCs with the greatest values of endemicity (E) were mainly associated with Monte and Yungas Forests areas. All patterns indicated strong tendency of the Yungas Forests as a possible endemism area. Our results indicate that distributional congruence centers are generally located in Yungas Forests areas and highlight the importance of these areas in conservation and historical biology. This new information will allow delimitation of areas in the region at a more detailed resolution in the future.
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Trypanosomes are a group of parasitic flagellates with medical and veterinary importance. Despite many species having been described in this genus, little is known about many of them. Here, we report a genetic and morphological characterization of trypanosomatids isolated from wild mammals from the Argentine Chaco region. Parasites were morphologically and ultrastructurally characterized by light microscopy and transmission electron microscopy. Additionally, 18s rRNA and gGAPDH genes were sequenced and analyzed using maximum likelihood and Bayesian inference. Morphological characterization showed clear characteristics associated with the Trypanosoma genus. The genetic characterization demonstrates that the studied isolates have identical sequences and a pairwise identity of 99% with Trypanosoma lainsoni, which belongs to the clade of lizards and snakes/rodents and marsupials. To date, this species had only been found in the Amazon region. Our finding represents the second report of T. lainsoni and the first record for the Chaco region. Furthermore, we ultrastructurally described for the first time the species. Finally, the host range of T. lainsoni was expanded (Leopardus geoffroyi, Carenivora, Felidae; and Calomys sp., Rodentia, Cricetidae), showing a wide host range for this species.
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A new species of flea (Siphonaptera: Rhopalopsyllidae) is described from sigmodontine rodents collected during a survey of small mammals in northwestern Argentina. The new species belongs to the subgenus Tetrapsyllus and can be distinguished from all species of the subgenus by characteristics of the modified abdominal segments and genitalia. A phylogenetic analysis of the genus Tetrapsyllus using morphological characters is presented and the analysis supports the erection of this new Tetrapsyllus species in the subgenus Tetrapsyllus. The unique occurrence of a sinus in the caudal margin of the sixth sternite of females that is present only in the subgenus Tetrapsyllus (also unique across the Order Siphonaptera) is provided with a discussion of how this adaptation is mirrored in the parallel development of a spur on the sclerotized inner tube of males. Additional host and locality data are recorded for Tetrapsyllus (P.) bleptus. A key to the genus Tetrapsyllus is provided. The increased diversity of flea fauna bordering a known plague endemic area in northwestern Argentina may prove useful in implementing sustainable control measures in the future.
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Here we present detailed descriptions and comparisons of the axial skeleton of seven species of bats belonging to five subfamilies of Phyllostomidae of different trophic guilds. The material examined consisted of 34 complete skeletons of seven species. For five of the studied species, previous descriptions have not been conducted, and for the vampires only limited information is available, so that descriptions for these species are here completed. The axial skeleton has characters that allow grouping of the species phylogenetically of the same subfamily and by feeding habits. At the same time, there are characters that associate species from different subfamilies with different types of diet or ways to obtain food.
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Osso e Ossos/anatomia & histologia , Quirópteros/anatomia & histologia , Animais , Argentina , Quirópteros/classificação , Quirópteros/genética , Feminino , Masculino , Filogenia , Asas de Animais/anatomia & histologiaRESUMO
Here, a detailed description of the forelimbs and hindlimbs of all living species of the genus Tympanoctomys are presented. These rodents, highly adapted to desert environments, are semi-fossorial with capacity to move on the surface as well as to build burrows. The shape, structure, and size of the limbs are described. Contrary to what was expected for scratch digging semi-fossorial species, Tympanoctomys have slender humerus, radius and ulna; with narrow epicondyles of the humerus and short olecranon of the ulna with poorly developed processes. Following our descriptions, no intrageneric morphological variation regarding to the configuration of the limbs was detected, probably due to phylogenetic proximity, and not related to specific variations in response to different use of substrates or habits. The obtained results constitute a source of previously unpublished information as well as an important base for future analysis in different studies, such as morphometric, morpho-functional, or phylogenetic researches.
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The mammalian and flea fauna of La Rioja Province is one of the least known from northwestern Argentina. In this study, the distribution and nomenclature of 13 species of fleas of bats and rodents from La Rioja Province are updated. Four species of fleas are recorded for the first time in La Rioja Province including a new record for northwestern Argentina, and two new flea-host associations. An identification key and distribution map are included for all known species of Siphonaptera of bats and rodents from La Rioja Province, Argentina.
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ABSTRACT Here we present detailed descriptions and comparisons of the axial skeleton of seven species of bats belonging to five subfamilies of Phyllostomidae of different trophic guilds. The material examined consisted of 34 complete skeletons of seven species. For five of the studied species, previous descriptions have not been conducted, and for the vampires only limited information is available, so that descriptions for these species are here completed. The axial skeleton has characters that allow grouping of the species phylogenetically of the same subfamily and by feeding habits. At the same time, there are characters that associate species from different subfamilies with different types of diet or ways to obtain food.
Assuntos
Animais , Masculino , Feminino , Osso e Ossos/anatomia & histologia , Quirópteros/anatomia & histologia , Filogenia , Argentina , Asas de Animais , Quirópteros/classificação , Quirópteros/genéticaRESUMO
A new species of flea of the genus Cleopsylla Rothschild, 1914 (Siphonaptera: Stephanocircidae) is described from sigmodontine rodents from northwestern Argentina. In Argentina, the genus was cited for the first time in 2008, but the species was erroneously identified. An identification key to species of Cleopsylla is presented.
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Infestações por Pulgas/veterinária , Doenças dos Roedores/parasitologia , Sigmodontinae/parasitologia , Sifonápteros/classificação , Animais , Argentina , Feminino , Infestações por Pulgas/parasitologia , Masculino , Sifonápteros/anatomia & histologiaRESUMO
A new species of flea of the genus Ctenidiosomus Jordan, 1931 (Siphonaptera: Pygiopsyllidae) is described from Phyllotisosilae J. A. Allen, 1901, from Salta Province, Argentina. This is the first time that Ctenidiosomus has been recorded in Argentina. A key to species of males of Ctenidiosomus is presented.
ResumenUna nueva especie de pulga del género Ctenidiosomus Jordan, 1931 (Siphonaptera: Pygiopsyllidae) es descripta de Phyllotisosilae J. A. Allen, 1901, de la provincia de Salta, Argentina. Cabe mencionar que es la primera vez que el género Ctenidiosomus ha sido registrado en Argentina. Se ofrece una clave para los machos de las especies de Ctenidiosomus.
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Neotyphloceras crassispina hemisus Jordan is redescribed from male and female specimens collected at the type locality (Otro Cerro, Catamarca Province, Argentina) and nearby localities. New diagnostic morphological characters for both sexes are provided, which include the shape of the upper lobe of the fixed process of clasper, the crochet of the aedeagus and the shape and chaetotaxy of the distal arm of sternum IX for males, and the contour of the distal margin of sternum VII for females.
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Infestações por Pulgas/veterinária , Doenças dos Roedores/parasitologia , Sigmodontinae/parasitologia , Sifonápteros/classificação , Animais , Feminino , Infestações por Pulgas/parasitologia , Masculino , Sifonápteros/anatomia & histologia , América do SulRESUMO
The genus Nonnapsylla Wagner, 1938 (Craneopsyllinae) includes only 1 species, Nonnapsylla rothschildi Wagner, 1938 . Two subspecies are recognized by the shape of the dorsal margin of the helmet, apical shape of the spines in helmet and genal combs, length of first and fourth segments of the maxillary palpus, and shape of the hilla of the spermatheca. The validity of the characters used to separate the 2 subspecies of Nonnapsylla rothschildi Wagner, 1938 is discussed based on information from the literature, as well as from direct observation of type specimens and specimens collected in northwestern Argentina. We conclude that Nonnapsylla rothschildi wagneri Johnson, 1957 should be considered as a synonym of the nominal subspecies. We also extend the southern limits of the distribution of the species and report its presence in Argentina.
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Infestações por Pulgas/veterinária , Doenças dos Roedores/parasitologia , Sifonápteros/classificação , Animais , Argentina/epidemiologia , Feminino , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/parasitologia , Masculino , Doenças dos Roedores/epidemiologia , Roedores , Sifonápteros/anatomia & histologiaRESUMO
The northern Amazon Basin in Peru is one of the most diverse areas for small mammals in the world. In this work, I present information related to the diversity of bat species in the Amazonian region of Iquitos, Peru, where nearly 60% of the 152 bat species known to Peru recorded. Unlike in previous investigations in this area, bat surveys were designed to detect species living in urban and rural areas. The results have added a new bat species (Eumops delticus) to the Peruvian fauna, eight new species for the region around Iquitos (Peropteryx macrotis, Peropteryx pallidoptera, Anoura caudifer, Lionycteris spurrelli, Vampyrum spectrum, Thyroptera lavali, Cynomops planirostris, and Molossus coibensis), and a new species for Northeast Peru (Eumops maurus).
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Quirópteros/classificação , Animais , Quirópteros/anatomia & histologia , Feminino , Masculino , PeruRESUMO
As part of a prospective study of leptospirosis and biodiversity of Leptospira in the Peruvian Amazon, a new Leptospira species was isolated from humans with acute febrile illness. Field trapping identified this leptospire in peridomestic rats (Rattus norvegicus, six isolates; R. rattus, two isolates) obtained in urban, peri-urban, and rural areas of the Iquitos region. Novelty of this species was proven by serological typing, 16S ribosomal RNA gene sequencing, pulsed-field gel electrophoresis, and DNA-DNA hybridization analysis. We have named this species "Leptospira licerasiae" serovar Varillal, and have determined that it is phylogenetically related to, but genetically distinct from, other intermediate Leptospira such as L. fainei and L. inadai. The type strain is serovar Varillal strain VAR 010(T), which has been deposited into internationally accessible culture collections. By microscopic agglutination test, "Leptospira licerasiae" serovar Varillal was antigenically distinct from all known serogroups of Leptospira except for low level cross-reaction with rabbit anti-L. fainei serovar Hurstbridge at a titer of 1:100. LipL32, although not detectable by PCR, was detectable in "Leptospira licerasiae" serovar Varillal by both Southern blot hybridization and Western immunoblot, although on immunoblot, the predicted protein was significantly smaller (27 kDa) than that of L. interrogans and L. kirschneri (32 kDa). Isolation was rare from humans (2/45 Leptospira isolates from 881 febrile patients sampled), but high titers of MAT antibodies against "Leptospira licerasiae" serovar Varillal were common (30%) among patients fulfilling serological criteria for acute leptospirosis in the Iquitos region, and uncommon (7%) elsewhere in Peru. This new leptospiral species reflects Amazonian biodiversity and has evolved to become an important cause of leptospirosis in the Peruvian Amazon.
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Leptospira/genética , Leptospira/imunologia , Adulto , Animais , Antígenos de Bactérias/imunologia , Técnicas de Tipagem Bacteriana , Southern Blotting , Western Blotting , Cricetinae , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Leptospira/classificação , Leptospirose/microbiologia , Mesocricetus , Dados de Sequência Molecular , Peru , Reação em Cadeia da Polimerase , Estudos Prospectivos , RNA Ribossômico 16S/genética , Ratos , Sorotipagem , Adulto JovemRESUMO
The role of bats as potential sources of transmission to humans or as maintenance hosts of leptospires is poorly understood. We quantified the prevalence of leptospiral colonization in bats in the Peruvian Amazon in the vicinity of Iquitos, an area of high biologic diversity. Of 589 analyzed bats, culture (3 of 589) and molecular evidence (20 of 589) of leptospiral colonization was found in the kidneys, yielding an overall colonization rate of 3.4%. Infection rates differed with habitat and location, and among different bat species. Bayesian analysis was used to infer phylogenic relationships of leptospiral 16S ribosomal DNA sequences. Tree topologies were consistent with groupings based on DNA-DNA hybridization studies. A diverse group of leptospires was found in peri-Iquitos bat populations including Leptospira interrogans (5 clones), L. kirschneri (1), L. borgpetersenii (4), L. fainei (1), and two previously undescribed leptospiral species (8). Although L. kirschenri and L. interrogans have been previously isolated from bats, this report is the first to describe L. borgpetersenii and L. fainei infection of bats. A wild animal reservoir of L. fainei has not been previously described. The detection in bats of the L. interrogans serovar Icterohemorrhagiae, a leptospire typically maintained by peridomestic rats, suggests a rodent-bat infection cycle. Bats in Iquitos maintain a genetically diverse group of leptospires. These results provide a solid basis for pursuing molecular epidemiologic studies of bat-associated Leptospira, a potentially new epidemiologic reservoir of transmission of leptospirosis to humans.