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Orthohantaviruses (genus Orthohantavirus, family Hantaviridae) are the etiologic agents of Hantavirus Pulmonary Syndrome in the Americas. In South America, orthohantaviruses are highly diverse and are hosted by sigmodontine rodents (subfamiliy Sigmodontinae, family Cricetidae), an also diverse group of rodents. The aims of this work were to (1) identify orthohantavirus hosts and (2) to study the spatial and temporal variations in the prevalence of infection and their associations with community, environmental and individual characteristics, in different environments of Misiones province, northeastern Argentina. Live-capture sessions were carried out during two years in different land uses, with a trapping effort of 31,653 trap nights. We captured 719 individuals from the species Akodon montensis, Rattus rattus, Mus musculus, Calomys tener, Thaptomys nigrita, Oligoryzomys nigripes, Euryoryzomys russatus, Oligoryzomys flavescens, Brucepattersonius sp., and Juliomys pictipes. Antibodies against orthohantavirus were detected in Akodon montensis in one natural protected and one periurban areas, and it was the most abundant species in almost every study sites. We observed the presence of spatial focality of orthohantavirus infection and a positive association with host abundance suggesting the existence of a threshold density. At the individual level, large, reproductively active, and male individuals were more likely to have antibodies against orthohantavirus. This is the first record of orthohantavirus infection in A. montensis in Argentina, which shows the importance of investigations about emerging diseases.

Ecological studies of host-parasite interactions are common in rodents. However, despite the widespread occurrence of endoparasites in those animals, there is a lack of information about the community structure of these parasites. The aims of this study were to describe the species composition and the community structure of helminths of the rodents Oligoryzomys nigripes , Akodon montensis and Euryoryzomys russatus (Rodentia, Sigmodontinae), and to investigate the influence of host species, age and gender on the abundance and prevalence of helminths. The pattern of the metacommunity structure of the helminths of A. montensis was also analysed. Small mammals were captured in Serra do Tabuleiro State Park, Santo Amaro da Imperatriz, state of Santa Catarina, Brazil. Helminths were identified and counted. Each species had its abundance, intensity and prevalence estimated for each host. The influence of host species, age and gender on abundance and prevalence of helminths was tested using generalized linear models (GLM). The metacommunity was analysed by calculating the Elements of Metacommunity Structure (EEM) for infracommunities. In O. nigripes, the species Guerrerostrongylus zetta and Stilestrongylus lanfrediae (Nematoda, Heligmonellidae) were found. A. montensis harboured G. zetta , Trichofreitasia lenti (Nematoda, Heligmonellidae), Trichuris navonae (Nematoda, Trichuridae), Angiostrongylus sp. (Nematoda, Angiostrongylidae), Litomosoides chagasfilhoi (Nematoda, Onchocercidae) and Rodentolepis akodontis (Plathyhelmintes, Cestoda). In the E. russatus rodent, the species G. zetta, Stilestrongylus rolandoi (Nematoda, Heligmonellidae) and Raillietina guaricanae (Plathyhelmintes, Cestoda) were found. This study presented new records of the helminths S. rolandoi and R. guaricanae in E. russatus , and of L. chagasfilhoi in A. montensis . The helminth metacommunity structure of A. montensis presented a random pattern of species distribution, characterized by a non-coherent structure along the environmental gradient, indicating different environmental requirements due to the infection of this host by helminths with different life cycles.

Variation in primary productivity has been described for an extensive range of natural systems and may lead to remarkable bottom-up effects on consumer communities at higher trophic levels. During a standardized sampling of the small mammal assemblage in the Reserva Florestal Morro Grande, SP, Brazil, we documented a bamboo blooming followed by an increase in abundance of small mammals. Here we described the effects of this blooming of the assemblage of small mammals and evaluated if (i) the abundance of frugi-/granivore species is affected more strongly than the abundance of insect-/omnivore species and (ii) due to the massive food availability in the habitat (bamboo seeds), body mass index of one of the affected species, the rodent Euryoryzomys russatus, will increase after the bamboo blooming. Although some species became more abundant, the difference was not related to species diet. We did find a significant increase in the body weight of Euryoryzomys russatus after the bamboo blooming. We emphasize that an infrequent and poorly known event like bamboo blooming can have a major impact on rodent population dynamics, regardless of the species diet, increasing abundance, and weight bottom-up controlled by the massive availability of food resources.

Hassalstrongylus luquei n. sp. es descrito en el intestino delgado de Euryoryzomys russatus (Rodentia: Sigmodontinae) colectado en la Mata Atlantica (Estado de Río de Janeiro, Angra dos Reis, Brasil). El género Hassalstrongylus Durette-Desset de 1971 incluye 16 especies neotropicales. Las características más importantes de la nueva especie son: la bursa caudal subsimétrica con un tipo 2-2-1, rayos 8 ramificados en la mitad de la longitud del tronco dorsal, el tronco lateral derecho es mayor que el izquierdo y las espículas son las más grandes del género. Sólo tres especies de Hassalstrongylus tienen los rayos 8 no emergentes en la base del tronco, éstas son: H. mazzai, H. aduncus y H. echalieri. Sin embargo, la presente especie se distingue de H. mazzai por presentar los radios dorsales divididos en la cuarta parte del tronco, H. bocqueti por tener los rayos 5 bifurcados en tercera parte del tronco y H. echalieri por tener un patrón de 2-2-1.

Rodents are small mammals that can be parasitized by various helminths. This study aimed to identify and describe the ecological indicators of infection in rodents captured in fragments of the Atlantic Forest in the western region of Paraná State, Brazil. Sixty-eight specimens of five rodent species were collected, necropsied, and inspected in search of helminths. The parasites were stored in 70% ethanol, morphologically identified, and counted for calculation of infection indicators. Fourteen species of helminths and one species of Crustacea were recorded: ten in Akodon montensis, four in Mus musculus, two in Thaptomys nigrita, two in Oligoryzomys nigripes, and one in Euryoryzomys russatus. The registered species of parasites were: Rodentolepis akodontis, Angiostrongylus sp., Protospirura numidica criceticola, Trichuris navonae, Syphacia alata, Syphacia criceti, Syphacia evaginata, Trichofreitasia lenti, Stilestrongylus aculeata, Stilestrongylus eta, Stilestrongylus gracielae, Stilestrongylus franciscanus, Stilestrongylus moreli, Stilestrongylus sp., and Pentastomida gen. sp. A positive correlation between the intensity of infection of T. navonae and T. lenti was observed with the body condition index of the host A. montensis. For all species, this study represents a new register of locality, and for eight of them a new host. Resumo Roedores são pequenos mamíferos que podem ser parasitados por uma diversidade de helmintos. Este estudo teve como objetivo identificar e descrever os indicadores ecológicos de infecção por helmintos, em roedores capturados em fragmentos de Mata Atlântica, na região Oeste do Estado do Paraná, Brasil. Sessenta e oito animais foram coletados, necropsiados e inspecionados em busca de helmintos. Os parasitas foram armazenados em etanol 70%, identificados morfologicamente e contados para o cálculo dos indicadores de infecção. Quatorze espécies de helmintos e uma espécie de crustáceo foram registradas: dez em Akodon montensis, quatro em Mus musculus, duas em Thaptomys nigrita, duas em Oligoryzomys nigripes e uma em Euryoryzomys russatus. As espécies de parasitas registradas foram: Rodentolepis akodontis, Angiostrongylus sp., Protospirura numidica criceticola, Trichuris navonae, Syphacia alata, Syphacia criceti, Syphacia evaginata, Trichofreitasia lenti, Stilestrongylus aculeata, Stilestrongylus eta, Stilestrongylus gracielae, Stilestrongylus franciscanus, Stilestrongylus moreli, Stilestrongylus sp., e Pentastomida gen. sp. Uma correlação positiva entre a intensidade parasitária de T. navonae e T. lenti foi observada com o índice de condição corporal do hospedeiro A. montensis. Para todas as espécies, este estudo representa um novo registro de localidade, e para oito delas um novo hospedeiro.

Euryoryzomys russatus Karyotype: 2n = 80 and FN = 86. Autosomal complement: four small metacentric pairs and 35 acrocentric pairs large to small decreasing in size. Sex chromosomes: X chromosome presented three different morphologies, a large metacentric, a large submetacentric, and a large subtelocentric; Y chromosome presented three different morphologies, a medium submetacentric, a medium-small subtelocentric, and a small acrocentric. The differences on the X chromosome morphology, apparently was due to heterochromatin variation since the C-bands can occur on the centromeric region or the whole short arm can be heterochromatic. NORs bands were detected in two to four small acrocentric pairs. G-banding was also performed (Andrades-Miranda et al. 2000, pp. 465, Fig. 2D). This same karyotype was also reported by Silva et al. (2000), Paresque et al. (2004), Pinheiro & Geise (2008), Di-Nizo et al. (2014), and Gatto-Almeida et al. (2016). A female with 2n = 80/81 being an XX/XXX mosaic was reported by Andrades-Miranda et al. (2000)., Published as part of Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis & Yonenaga-Yassuda, Yatiyo, 2020, A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes, pp. 1-111 in Zootaxa 4876 (1) on page 16, DOI: 10.11646/zootaxa.4876.1.1, http://zenodo.org/record/4423612, {"references":["Andrades-Miranda, J., Zanchin, N. I. T., Oliveira, L. F. B., Langguth, A. R. & Mattevi, M. S. (2000) Cytogenetic studies in nine taxa of the genus Oryzomys (Rodentia, Sigmodontinae) from Brazil. Mammalia, 65 (4), 461 - 472. https: // doi. org / 10.1515 / mamm. 2001.65.4.461","Silva, M. J. J., Percequillo, A. R. & Yonenaga-Yassuda, Y. (2000) Cytogenetics and systematic approach on a new Oryzomys species, of the nitidus group (Sigmodontinae, Rodentia) from Northeastern Brazil. Caryologia, 53, 219 - 226. https: // doi. org / 10.1080 / 00087114.2000.10589199","Paresque, R., Souza, W. P., Mendes, S. L. & Fagundes, V. (2004) Composicao cariotipica da fauna de roedores e marsupiais de duas areas de Mata Atlantica do Espirito Santo, Brasil. Boletim do Museu de Biologia Mello Leitao, 17, 5 - 33.","Pinheiro, P. S. & Geise, L. (2008) Non-volant mammals of Picinguaba, Ubatuba, state of Sao Paulo, southeastern Brazil. Boletim do Museu de Biologia Mello Leitao, 23, 51 - 59.","Di-Nizo, C. B., Neves, C. L., Vilela, J. F. & Silva, M. J. J. (2014) New karyologycal data and cytotaxonomic considerations on small mammals from Santa Virginia (Parque Estadual da Serra do Mar, Atlantic Forest, Brazil). Comparative cytogenetics, 8 (1), 11 - 30. https: // doi. org / 10.3897 / compcytogen. v 8 i 1.6430","Gatto-Almeida, F., Pontes, J. S., Sbalqueiro, I. J., Hass, I., Tiepolo, L. M. & Quadros, J. (2016) Diversidade, biogeografia, caracterizacao cariotipica e tricologica dos pequenos mamiferos nao voadores do Parque Estadual Rio da Onca, Litoral Sul do Parana. Papeis avulsos de zoologia, 56 (7), 69 - 96. https: // doi. org / 10.11606 / 0031 - 1049.2016.56.07"]}

A new species of Nippostrongylinae (Nematoda: Heligmonellidae), Stilestrongylus rolandoi n. sp., is described from specimens collected from the small intestine of the rodent Euryoryzomys russatus in the Atlantic Forest (Santo Amaro da Imperatriz, Santa Catarina state, southern Brazil). The genus Stilestrongylus includes 23 species, which parasitize rodents occurring in the Neotropical region. Stilestrongylus aureus (Durette-Desset & Sutton, 1985) from Argentina, S. azarai (Durette-Desset & Sutton, 1985) from Argentina, S. flavescens (Sutton & Durette-Desset, 1991) from Uruguay, S. franciscanus (Digiani & Durette-Desset, 2002) from Argentina, S. gracielae (Digiani & Durette-Desset, 2006) from Argentina, and S. oryzomysi (Sutton & Durette-Desset, 1991) from Argentina are closely related to Stilestrongylus rolandoi n. sp., all having caudal bursa patterns of types 1–4 in one of the lobes. Stilestrongylus rolandoi n. sp. is distinguished from the aforementioned species by its ray 6 being short in relation to rays 4 and 5, which are long and robust, and by having caudal bursa patterns of types 1–4 in both lobes. The new species has 27 ridges in the mid-body in males, and 24 in females, and has one of the highest ratios of spicule length to body length (21−33%) in this genus.

To contribute to the knowledge of the role of small mammals in the transmission cycle of tegumentary leishmaniasis caused by Leishmania braziliensis, we studied the small mammal community and its temporal and spatial association with phlebotominae, as well as small mammal infection by Leishmania spp. by PCR-RFLP analyses in an endemic area of northeastern Argentina. Ten small mammal samplings were conducted (2007–2009, 7506 Sherman trap nights and 422 cage trap nights). In two of these samplings, 16 capture stations each one consisting of a CDC light trap to capture phlebotominae, two to four Sherman traps and two cage traps were placed. We found co-occurrence of phlebotominae and small mammal captures in four stations, which were all the stations with small mammal captures and yielded 97% (2295 specimens, including 21 gravid females) of the total phlebotominae captures, suggesting that small mammals may provide a potential source of blood for phlebotominae females. One Didelphis albiventris and two Rattus rattus were associated with high captures of Nyssomyia whitmani, vector of L. braziliensis in the study area. The PCR-RFLP analyses confirm the presence of L. braziliensis in two sigmodontine small mammals (Akodon sp. and Euryoryzomys russatus) for the first time in Argentina, to our knowledge. Fil: Fernández, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. La Red de Investigación de la Leishmaniasis en Argentina; Argentina Fil: Fraschina, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina Fil: Acardi, Soraya Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. La Red de Investigación de la Leishmaniasis en Argentina; Argentina Fil: Liotta, Domingo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. La Red de Investigación de la Leishmaniasis en Argentina; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Laboratorio de Biología Molecular Aplicada; Argentina. Ministerio de Salud de la Nación; Argentina Fil: Lestani, Eduardo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Salud de la Nación; Argentina Fil: Giuliani, Magalí Gabriela. Ministerio de Salud de la Nación; Argentina Fil: Busch, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina Fil: Salomón, Oscar Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. La Red de Investigación de la Leishmaniasis en Argentina; Argentina. Ministerio de Salud de la Nación; Argentina

A new species of Heligmonellidae (Trichostrongylina, Heligmosomoidea), Stilestrongylus kaaguyporai n. sp. is described from the small intestine of Euryoryzomys russatus (Rodentia, Cricetidae, Sigmodontinae) from the Argentine Atlantic Forest, in the Misiones province. The new species was found at Campo Anexo Manuel Belgrano, Reserva de Vida Silvestre Urugua-í and Parque Provincial Urugua-í, with a prevalence of 73% in 15 hosts examined. Stilestrongylus includes 24 Neotropical species, all parasitic in rodents, mostly Sigmodontinae. Stilestrongylus kaaguyporai n. sp. can be differentiated from its congeners by the following characters: caudal bursa dissymmetrical with right lobe larger and pattern of type1–4 in both lobes, rays 6 not forming a lateral trident with rays 4 and 5, rays 8 with dissymmetrical pathway, genital cone hypertrophied with a conspicuous hood-like projection and females with a marked dorso-ventral torsion of the posterior end. This report is the second record of a Stilestrongylus species in E. russatus, increasing to nine the number of parasitic species known from this host., Facultad de Ciencias Naturales y Museo, Centro de Estudios Parasitológicos y de Vectores

Rickettsia parkeri strain Atlantic rainforest (SAR) is the etiological agent of a spotted fever group rickettsiosis in Brazil, where it is transmitted to humans by the tick Amblyomma ovale. A previous study demonstrated that R. parkeri SAR was successfully maintained in A. ovale ticks by transstadial and transovarial passages; however, because this agent induced lower reproduction rates in A. ovale, the participation of a vertebrate amplifier host, yet to be determined, was speculated. Since the rice rat Euryoryzomys russatus was demonstrated to be the most important host for immature stages of A. ovale in a focus of R. parkeri SAR transmission, the present study evaluated the competence of rice rats to act as amplifying host of R. parkeri SAR for A. ovale ticks. Rice rats were infested with R. parkeri SAR-infected A. ovale nymphs, and four days later with uninfected A. ovale larvae. Rickettsial transmission to rats was confirmed by seroconversion to R. parkeri antigens. Detached engorged larvae were allowed to molt to nymphs, in which rickettsial DNA was detected in up to 60% (mean: 20%) of the specimens. When part of these nymphs was allowed to feed on susceptible rice rats, rickettsial transmission was confirmed by seroconversion, indicating that there was successful horizontal transmission of R. parkeri SAR from infected nymphs to uninfected larvae in the previous acquisition infestations. Because we used naive, susceptible rats, we infer that this horizontal transmission occurred via a systemic infection (rickettsemia) in the rat. Our results, coupled with previous epidemiological studies, suggest that under natural conditions rice rats could be acting as amplifying hosts of R. parkeri SAR to A. ovale ticks.

Dietary studies allow us to understand important ecological patterns such as intra- and interpopulation variation and interspecific differences regarding the use of food sources. Stable isotopes have been successfully employed to detect dietary differences between species and feeding shifts within a species, as a response to age, habitat use, and resource availability. Here we investigated the stable isotope compositions of carbon and nitrogen of young and adult specimens of Euryoryzomys russatus and Sooretamys angouya and their stomach contents, in a complex mosaic of vegetation in the Brazilian Atlantic Forest. Isotopes indicated a pronounced inter- and intraspecific plasticity in resource use for E. russatus and S. angouya. Plant sources were the prevalent feeding items for E. russatus, with low to intermediate consumption of arthropods. For S. angouya, plants were dominant in the stomach content, but arthropod arose as an important source. E. russatus showed more variation in isotopic signature between grids than S. angouya, suggesting that the former was more affected by habitat changes. These results allow us to better understand the ontogeny, diet and the behavioral responses to environmental variations of both species. Finally, our study contributes to reduce the lack of knowledge about sympatric species ecology and aggregates information for their conservation. Fil: Bovendorp, Ricardo Siqueira. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil. Universidade Estadual Paulista “Júlio de Mesquita Filho”; Brasil Fil: Simoes Libardi, Gustavo. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina Fil: Sarmento, Mariana Montagner de Moraes. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil Fil: Camargo, Plínio Barbosa. Universidade de Sao Paulo; Brasil Fil: Reis Percequillo, Alexandre. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil

406. Russet Rice Rat Euryoryzomys russatus French: Oryzomys roux / German: Rostbraune Reisratte / Spanish: Rata arrocera bermeja Other common names: Russet Euryoryzomys, Russet Oryzomys Taxonomy. Hesperomys russatus Wagner, 1848, Ipanema, Sao Paulo, Brazil. This species is monotypic. Distribution. E Brazil (from Ceara S to N Rio Grande do Sul states), E Paraguay, and NE Argentina (Misiones Province). Descriptive notes. Head-body 98-179 mm, tail 99-181 mm, ear 18-5-25 mm, hindfoot 28-5-40 mm; weight 20-100 ¢g (mean 60 g). The Russet Rice Rat is very similar to the Elegant Rice Rat (FE. nitidus), but it has greater external and cranial dimensions. Compared with the Elegant Rice Rat, the Russet Rice Rat has longer and brighter dorsal pelage, shorter incisive foramina, and small sphenopalatine vacuities. Habitat. Forested coastal plains, evergreen semideciduous forest of coastal highlands, and coastal islands. Food and Feeding. Diet of the Russet Rice Rat contains fruit, vegetal matter, and arthropods. Breeding. The Russet Rice Rat breeds year-round. Females reaches sexual maturity at c.115 days old and can have more than 6 litters/year. Activity patterns. Trapping data suggests that the Russet Rice Rat is nocturnal and terrestrial. Movements, Home range and Social organization. Home ranges are 0-16-1-1 ha; average of density is 5-3 ind/ha. The Russet Rice Rat uses dry leaves and grass to build egg-shaped nests around fallen logs and aerial roots. Status and Conservation. Classified as Least Concern on The [UCN Red List. Bibliography. Bergallo (1994), Bovendorp et al. (2017), Briani et al. (2001), Libardi & Percequillo (2016), Musser & Carleton (2005), Pardini (2004), Percequillo (2015d), Percequillo, Weksler, Langguth et al. (2016)., Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 425, DOI: 10.5281/zenodo.6707142

Physiological concepts and tools can help us to understand why organisms and populations respond to habitat fragmentation in the way they do, and allow us to determine the mechanisms or individual characteristics underlying this differential sensitivity. Here, we examine food intake, relative medullary thickness and distribution/expression of water channel aquaporin-1 in three species of South American rodents that have been reported to have different levels of tolerance to habitat fragmentation (Akodon montensis, Oligoryzomys nigripes, and Euryoryzomys russatus), using a classic water deprivation experiment to assess their abilities to cope with water shortage. We believe the mechanisms underlying this differential sensitivity are related to the organisms' capacities to maintain water balance, and therefore the species more tolerant to habitat fragmentation (A. montensis and O. nigripes) should have a higher capacity to maintain water balance. We found that A. montensis and O. nigripes were more tolerant to water deprivation than E. russatus, and this difference appears to be unrelated to differences in food ingestion rate. O. nigripes showed the highest values for RMT, followed by A. montensis and E. russatus. However all species showed RMT values that were 2.2% to 14.1% below the lower prediction limit when compared to other rodents through allometric relationships. Water deprivation seems to trigger changes in the distribution of aquaporin-1, mostly for O. nigripes and E. russatus, which may contribute to water balance maintenance. Our data suggest that these intrinsic physiological differences among these species could provide a mechanism for their differential tolerance of habitat fragmentation. J. Exp. Zool. 323A: 731-744, 2015. © 2015 Wiley Periodicals, Inc.

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

From July to October 2009, the frugivorous fauna associated with palmito palms (Euterpe edulis) was studied to identify possible seed dispersers in Atlantic forest remnants on Santa Catarina Island, southern Brazil. The animals approaching or feeding on fruits were recorded by camera traps directed towards infructescences bearing ripe fruits and towards fruit patches on the ground. In a total sampling effort of 165 trap-days, 48 feeding events were recorded. Three birds, the Channel-billed Toucan (Ramphastos vitellinus), Speckled Chachalaca (Ortalis guttata) and White-necked Thrush (Turdus albicollis), and four mammal species, the coati (Nasua nasua), russet rice rat (Euryoryzomys russatus), South American water rat (Nectomys squamipes) and the tayra (Eira barbara) were identified. The highest number of feeding events was recorded for O. guttata, followed by R. vitellinus and E. russatus. Although the number of detected species was low, seed dispersal of E. edulis fruits on Santa Catarina Island is likely...

Understanding the mechanisms that determine the abundance of small mammals in fragmented landscapes is crucial for the conservation of their populations. The abundance of marsupials and rodents was studied from 1999 to 2001 in fragments of Atlantic Forest. A capture–mark–recapture study was carried out in three small fragments (2.8–9.1 ha), two medium-sized fragments (158.9–197.6 ha) and three control areas within an 840-ha forest block. Twenty small mammal species were captured and the abundance was higher in small fragments than in either medium-sized or large ones. The marsupial Marmosops incanus and the rodent Euryoryzomys russatus were more abundant in small fragments; the marsupials Caluromys philander and Gracilinanus microtarsus showed a trend in the opposite direction. Our results suggest that several species are positively affected by increased productivity or by the habitat changes produced by edge effects in small fragments, including a sparser canopy and denser understorey vegetation.

We tested the hypothesis that microhabitat variables, abundance of terrestrial rodents, and microhabitat selection patterns of terrestrial rodents vary between the cool-dry and warm-wet season in the Atlantic forest of Brazil. We selected variables associated with ecological factors potentially important to terrestrial rodents (physical structure of litter and woody debris, and arthropod availability) and established 25 small, independent sampling units covering 36 ha of a homogenous, mature Atlantic forest patch. Litter humidity and height, amount of small woody debris, arthropod availability, and terrestrial rodent abundance increased, whereas the quantity of large woody debris decreased in the warm-wet season. Greater spatial segregation among terrestrial rodents also was observed in this season, especially between morphologically similar species. The distribution of 3 of the 4 most common terrestrial rodents was influenced by microhabitat variables in at least 1 of the seasons, and these species also differed in their pattern of microhabitat selection between seasons. In general, the amount of small woody debris and litter humidity were more important for the microscale distribution of terrestrial rodents in the cool-dry season, whereas in the mild warm-wet season species distributions were associated with food availability or were not clearly influenced by the measured variables. The patterns of microhabitat selection by 3 common terrestrial rodents, which were associated with features that characterize old-growth forest, may be responsible for their vulnerability to forest fragmentation.

In this study, the geographic patterns of genetic variation of three rodent species belonging to the tribe Oryzomyini were investigated using the mitochondrial cytochrome b and nuclear IRBP genes in biomes that are undergoing degradation processes to a greater or lesser degree. The samples are from 25 collecting localities distributed throughout the Amazon, Cerrado, Atlantic Forest, and Pampa biomes. The results show that the three species have a population and geographic structure, besides being in demographic equilibrium. The phylogenetic analyses performed on Euryoryzomys russatus and Hylaeamys megacephalus showed these specimens grouped in three distinct clades forming geographic gradients (North-South direction in H. megacephalus). Intraspecific genetic divergence was higher in H. megacephalus (4.53%), followed by E. russatus (1.79%), and lowest in Sooretamys angouya (0.88%). The results obtained indicate that, necessarily, the management strategies to preserve genetic diversity should be different for each species, since each of them presented specific population parameters.

During 2013-2014, adult ticks were collected on the vegetation and subadult ticks were collected from small mammals [Didelphis aurita Wied-Neuwied, Sooretamys angouya (Fischer), Euryoryzomys russatus (Wagner), Akodon montensis Thomas, Oxymycterus judex Thomas] in an Atlantic rainforest reserve in southern Brazil. Analyses of the external morphology of the adult ticks revealed that they represent a new species, Amblyomma yucumense n. sp. Partial 16S rRNA sequences generated from males, females, and nymphs were identical to each other and closest (95% identity) to corresponding sequences of Amblyomma dubitatum Neumann. A. yucumense is morphologically and genetically closest related to A. dubitatum. Dorsally, male of these species can be separated by major longitudinal pale orange stripes associated with a pseudoscutum indicated by a pale stripe in A. yucumense, in contrast to pale creamy longitudinal stripes and absence of pseudoscutum in A. dubitatum. Ventrally, male coxal I spurs are separated by a space narrower than external spur width in A. yucumense, and wider than external spur width in A. dubitatum. Females of the two species can be separated by coxal I spurs, longer in A. yucumense than in A. dubitatum. In addition, the adult capitulum and ventral idiosoma of A. yucumense are generally dark brown colored, while A. dubitatum is yellowish or light brown colored. The nymph of A. yucumense differs from A. dubitatum by the scutal cervical groove length, slightly shorter in the former species. Currently, A. yucumense is restricted to southern Brazil.

Paracoccidioidomycosis (PCM) is a systemic mycosis prevalent in Brazil and other Latin American countries. The etiological agents of PCM are the thermo-dimorphic fungi Paracoccidioides brasiliensis and P. lutzii. Taking into account that the natural habitat of Paracoccidioides spp. is still undefined, domestic and wild animals could be useful as indicators of Paracoccidioides spp. presence in endemic areas. The objective of this study was to evaluate the infection of small wild mammals by P. brasiliensis in an endemic area for human PCM. Samples from 38 wild mammals from different species such as Akodon sp., Thaptomys nigrita, Euryoryzomys russatus, Oligoryzomys nigripes, Monodelphis sp., Sooretamys angouya, Abrawayaomys angouya, Abrawayaomys ruschii and Akodontinae sp. were evaluated by ELISA, immunodiffusion, histopathology, nested PCR and culture. The overall positivity to gp43 observed in the ELISA was 23.7 %. Samples from heart and liver of one O. nigripes were PCR positive, and the animal was also seropositive to gp43 in ELISA. This study showed that wild animals living in endemic areas for PCM are infected with P. brasiliensis and can be valuable epidemiological markers of the fungus presence in the environment. This is the first evidence of PCM infection in Akodon sp., E. russatus, T. nigrita and O. nigripes.

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. Fil: Panisse, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Robles, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Digiani, Maria Celina. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Notarnicola, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina Fil: Galliari, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Navone, Graciela Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina

SUMMARYRecently, a novel human rickettsiosis, namely Atlantic rainforest spotted fever, was described in Brazil. We herein report results of a survey led around the index case in an Atlantic rainforest reserve in Peruibe municipality, southeastern Brazil. ARickettsia parkeri-like agent (Rickettsiasp. Atlantic rainforest genotype) andRicketsia belliiwere isolated from adultAmblyomma ovaleticks collected from dogs. Molecular evidence of infection with strain Atlantic rainforest was obtained for 30 (12·9%) of 232A. ovaleadult ticks collected from dogs. As many as 88·6% of the 35 examined dogs had anti-Rickettsiaantibodies, with endpoint titres at their highest toR. parkeri. High correlation among antibody titres in dogs,A. ovaleinfestations, and access to rainforest was observed.Amblyomma ovalesubadults were found predominantly on a rodent species (Euryoryzomys russatus). From 17E. russatustested, 6 (35·3%) displayed anti-Rickettsiaantibodies, with endpoint titres highest toR. parkeri. It is concluded that Atlantic rainforest genotype circulates in this Atlantic rainforest area at relatively high levels. Dogs get infected when bitten byA. ovaleticks in the forest, and carry infected ticks to households. The role ofE. russatusas an amplifier host ofRickettsiatoA. ovaleticks deserves investigation.

The first and only study on gastrointestinal parasites of wild rodents in the Island of Santa Catarina was done in 1987. The aim of this study was to identify intestinal parasites from wild rodents in Santo Amaro da Imperatriz and Santa Catariana Island, and to compare the richness and composition of the gastrointestinal parasite community of both areas. Rodents were captured with live traps, and feces were screened using the sedimentation method and optical microscopy. The following species of rodents were captured in the two areas: Akodon montensis, Euryoryzomys russatus, Oligoryzomys nigripes and Nectomys squamipes. In Santo Amaro da Impetratriz, prevalent parasites were: A. montensis (51%), E. russatus (62%), O. nigripes (53%) and N. squamipes (20%). From the Island of Santa Catarina the rodent prevalence rates were: A. montensis (43%), E. russatus (59%), O. nigripes (30%) and N. squamipes (33%) and the collected parasites were: Hymenolepis sp., Longistriata sp., Strongyloides sp., Hassalstrongylus sp., Syphacia sp., Trichomonas sp., Ancylostomidae, Trichuridae, Oxyuridae and Eucoccidiorida. The species richness (10.6 ± 0.7) of the endoparasite comunity in the area located on the continent was higher (p < 0.01) and different (p = 0.001) from that of the area located on the island (6.9 ± 0.5).

Here we describe the stomach contents of nine small mammal species (seven rodents and two didelphid marsupials) co-occurring in an old-growth Atlantic forest area. For four terrestrial rodents, we also compared the importance of arthropods in the diet and the selection of arthropod groups by comparing consumption with availability. Small mammals and arthropods were sampled in a 36-ha grid containing 25 sampling stations spaced every 150 m, and 47 stomach contents were analysed. While plant matter was the predominant item in the stomach contents of two rodents (Oligoryzomys nigripes and Rhipidomys mastacalis), four species presented arthropods as the main food item (the rodents Brucepattersonius soricinus and Oxymycterus dasytrichus, and the marsupials Monodelphis n. sp. and Marmosops incanus) and three consumed more plant matter than arthropods, but had significant amounts of both items (the rodents Delomys sublineatus, Euryoryzomys russatus and Thaptomys nigrita). Our results suggest that differences in ...

The population dynamics and reproductive issues of two species of rodents of the family Cricetidae, Rice Rats (Euryoryzomys russatus) and Pygmy Rice Rats (Oligoryzomys nigripes), were studied for 24 months in an Atlantic Forest area in southern Brazil. Euryoryzomys russatus presented density-dependent population fluctuation, and recruitment was positively associated with temperature. Oligoryzomys nigripes displayed the lowest abundance, greatest population fluctuation and shortest permanence time. Abundance and survival were found to be negatively correlated with temperature. The sex ratio was not biased in any of the species.