Contribution to the knowledge about mammal collections in Brazil

We provide a brief introduction on the importance and use of scientific collections and a general overview of the articles that are part of the special issue of the Brazilian Journal of Mammalogy on Brazilian mammal collections. The 19 articles that comprise this issue refer to collections distributed across eight Brazilian states. Most of the collections hold specimens of living mammals, and two of them are paleontological collections. Two articles address specific orders of mammals, while the rest present data for all the orders. We hope that this issue represents a significant contribution to efforts to preserve Brazilian scientific collections, providing a more comprehensive view of their importance and the current and potential use of the specimens preserved therein.

Apresentamos uma breve introdução sobre a importância e uso de coleções científicas e um panorama geral dos artigos que fazem parte do número especial do Brazilian Journal of Mammalogy sobre coleções brasileiras de mamíferos. Os 19 artigos abrangem coleções distribuídas em oito estados da federação. Em sua maioria tratam de mamíferos viventes, sendo dois referentes a coleções paleontológicas. Dois artigos abordam ordens específicas de mamíferos e os demais apresentam dados para todas as ordens. Esperamos que este número represente uma contribuição significativa aos esforços para preservar as coleções científicas nacionais, fornecendo uma visão mais abrangente acerca das coleções e do uso atual e potencial dos espécimes nelas preservados.

NEW DATA ON THE THREATENED Cerradomys goytaca (RODENTIA, CRICETIDAE) / Nuevos datos sobre el amenazado Cerradomys goytaca (RODENTIA, CRICETIDAE)

ABSTRACT Cerradomys goytaca is a cricetid rodent endemic to "Restinga" formations from southeastern Atlantic Forest. It is known from only five localities, and it is considered endangered of extinction. Herein, we furnish new data on C. goytaca from an additional locality in Rio de Janeiro state. The present record provides new data on habitat and represents the westernmost geographic limit of this poorly known species.

RESUMEN Cerradomys goytaca es un roedor cricetideo endémico de las formaciones de Restinga del sureste de la Selva Atlantica. Es conocido solo en cinco localidades, y se considera en peligro de extinción. Aquí, proporcionamos nuevos datos sobre C. goytaca de una localidad adicional en el estado de Río de Janeiro. El presente registro proporciona nuevos datos del hábitat y representa el límite geográfico más occidental de esta especie poco conocida.

The First Quaternary Record of the Rodent Akodon kadiweu Brandão, Percequillo, D'Elía, Paresque, & Carmignotto, 2021 (Rodentia: Cricetidae: Sigmodontinae).

Rodents of the genus Akodon comprise 41 extant species, and are considered the most diverse genus of the tribe Akodontini. The most recently described extant species is Akodon kadiweu, known exclusively from Serra da Bodoquena, a karstic region located in Mato Grosso do Sul state, Brazil. Some sub-fossil and fossil specimens of Akodon have been reported in recent years for Brazil, but most remain unidentified at the species level. Here we examine the identity of Quaternary specimens of Akodon sp. from the limestone cave Nossa Senhora Aparecida, located in Serra da Bodoquena. Quantitative characters allowed the distinction of Akodon sp. specimens from smaller and larger congeners, and skull qualitative characters of nasal, interorbital region, supraorbital margins, zygomatic notches, zygomatic plate, incisive foramina, mesopterygoid fossa, mandible and molars allowed to identify these individuals as A. kadiweu. Our results revealed the first known past representatives of Akodon to be recorded in Mato Grosso do Sul, as well as western Brazil.

A new species of Akodon Meyen, 1833 (Rodentia: Cricetidae) from dry forests of the Amazonia-Cerrado transition.

Akodon is the most diverse genus of the tribe Akodontini, comprising 41 extant species. Although distributed in a wide range of environments in South America, the genus was long considered to be absent from Amazon Forest. Nonetheless, in recent decades, records of Akodon have been reported based on specimens from southern Amazonia, throughout the contact zone with Cerrado. Published data about the unique karyotype (2n=10), along with evidence of sister phylogenetic relationship (Cytb sequences) with Akodon cursor, a species from the Atlantic Forest, suggest that these specimens represent an undescribed species. Herein we hypothesize that these samples represent a new species of Akodon from Amazonia-Cerrado transitional areas. Through the analyses of 217 specimens from Mato Grosso and Pará states, Brazil, as well as 336 specimens of Akodon cursor species group from the Atlantic Forest, we provide qualitative and quantitative external and craniodental data that support their distinction in comparison with other congeners. The sister relationship between this new species and A. cursor provide additional evidence of a past connection between the two largest tropical forests of South America. Moreover, the recognition of Akodon n. sp. points to the presence of the genus in the Amazonia-Cerrado transition, an area currently under great anthropic pressure, highlighting the fact that we might be losing a portion of Brazilian biodiversity before even getting to know it.

Notes on natural history and behavior of Monodelphis glirina (Didelphimorphia, Didelphidae) and sympatry with congeners

Monodelphis glirina é endêmica da Amazônia e aspectos dos seus hábitos de vida e história natural são pouco conhecidos. Dados sobre a espécie foram coletados no norte de Mato Grosso, Brasil, incluindo observações sobre seu comportamento e simpatria com congêneres. Durante 10 expedições e com um esforço de 3.680 baldes-dia, foram capturados 29 M. glirina, três M. sacie um M. emiliae. Adultos representaram 82,8% das capturas de M. glirina e a razão sexual foi três machos para cada fêmea. A captura de jovens e fêmeas lactantes foi sazonal, uma vez que ambos foram capturados apenas na estação chuvosa. Observamos três eventos de M. glirina predando roedores em pitfall traps, todos com o mesmo comportamento de alimentação. Também registramos um individuo escalando uma árvore durante a noite, incluindo um video. Nosso trabalho contribui para uma melhor compreensão da ecologia desse gênero altamente diversificado e ainda pouco conhecido. (AU)

Non-volant mammals of the Ibura National Forest, northeastern Brazil

Less than 10% of the original Atlantic Forest cover now remains standing in the Brazilian state of Sergipe, although few scientific studies have focused on its mammalian diversity. The present study describes the diversity of non-volant mammals found in the Ibura National Forest (INF), based on live trapping, and direct and indirect observations. We sampled the IBF on six days per month between June 2012 and August 2013, using live-traps (Sherman-type) positioned in pairs (ground and understory). We equally sampled semideciduous forest and an abandoned Eucalyptusplantation with dense understory (over 30 years). We also used non-systematics methods (direct observations, vestiges, camera-trap, and opportunistic captures). We recorded 18 species, from 12 families and 7 orders considering all the applied methods. Among recorded species, Bradypus torquatusand Lontra longicaudisare considered threatened of extinction. Considering only the live-trapping (totaling 3,240 trapping nights), we captured 125 individuals (3.85% success) from four species, Marmosa demerarae(52%), Didelphis albiventris(19.2%), Cerradomys vivoi(15.2%), and M. murina(13.6%). Estimated and observed richness was the same, suggesting a satisfactory effort. Didelphis albiventrisand M. demeraraeshowed significantly higher captures in the dry seasons. Didelphis albiventrisand C.vivoishowed significantly higher captures in the substratum, and M. demeraraehigher in the understory. Cerradomysvivoishowed significantly higher captures in the Eucalyptusphytophysiognomy. Non-Metric Multidimensional Scaling and the ANOSIM showed a significant difference in the captured species among semidecidual forest and Eucalyptus. Despite the small area (144 ha), the INF still houses a relatively high mammalian diversity. Further investigations may help to understand the role of habitat reduction in the diversity and habitat partitioning among mammal species in the Atlantic Forest of Northeastern Brazil.

Systematics of the genus Oecomys (Sigmodontinae: Oryzomyini): molecular phylogenetic, cytogenetic and morphological approaches reveal cryptic species

Oecomys is a genus of Neotropical arboreal rodents composed of 17 species with diploid number ranging from 2n = 54 to 86. Despite this high taxonomic and karyotypic diversity, the species-level systematics remains uncertain. We investigated the phylogenetic relationships and species delimitation of Oecomys using multiple approaches based on cytogenetic, molecular (mtDNA and nuDNA sequences) and morphological data sets. Sampling included 73 individuals from 25 localities in Amazonia, Cerrado, Pantanal and the Atlantic Forest, as well as 128 DNA sequences from GenBank. Molecular species boundaries associated with karyotype, morphological characters and geographic distribution led us to recognize 15 distinct lineages in Oecomys. These include five major well-supported clades composed of O. bicolor, O. catherinae, O. cleberi, O. mamorae, O. paricola and O. roberti, which were hypothesized as species complexes with at least eight putative new taxa. Three new karyotypes are also reported for the genus: 2n = 54 (FN = 54), 2n = 62 (FN = 62) and 2n = 70 (FN = 74). Sympatry of up to four species with different diploid numbers recovered in distinct clades illustrates the complex evolutionary history in Oecomys. These data highlight the importance of combining cytogenetic, morphological and geographic information along with molecular coalescent analyses in developing species delimitation scenarios.

Systematics of the genus Oecomys (Sigmodontinae: Oryzomyini): molecular phylogenetic, cytogenetic and morphological approaches reveal cryptic species

Oecomys is a genus of Neotropical arboreal rodents composed of 17 species with diploid number ranging from 2n = 54 to 86. Despite this high taxonomic and karyotypic diversity, the species-level systematics remains uncertain. We investigated the phylogenetic relationships and species delimitation of Oecomys using multiple approaches based on cytogenetic, molecular (mtDNA and nuDNA sequences) and morphological data sets. Sampling included 73 individuals from 25 localities in Amazonia, Cerrado, Pantanal and the Atlantic Forest, as well as 128 DNA sequences from GenBank. Molecular species boundaries associated with karyotype, morphological characters and geographic distribution led us to recognize 15 distinct lineages in Oecomys. These include five major well-supported clades composed of O. bicolor, O. catherinae, O. cleberi, O. mamorae, O. paricola and O. roberti, which were hypothesized as species complexes with at least eight putative new taxa. Three new karyotypes are also reported for the genus: 2n = 54 (FN = 54), 2n = 62 (FN = 62) and 2n = 70 (FN = 74). Sympatry of up to four species with different diploid numbers recovered in distinct clades illustrates the complex evolutionary history in Oecomys. These data highlight the importance of combining cytogenetic, morphological and geographic information along with molecular coalescent analyses in developing species delimitation scenarios.

The genus Abrawayaomys Cunha and Cruz, 1979 (Rodentia: Cricetidae: Sigmodontinae): geographic variation and species definition

Abrawayaomys is a genus endemic to the Atlantic Forest with unique craniodental attributes within the radiation of sigmodontine rodents. Recent data hypothesized the existence of 2 species of Abrawayaomys, namely A. ruschii (from the Brazilian states of Espfrito Santo, Rio de Janeiro, and Sao Paulo) and A. chebezi (from the Argentinean province of Misiones and the Brazilian state of Parana), as well as a possible undescribed species (from the Brazilian state of Minas Gerais). Herein, based on a large series of recently collected specimens, we assessed the congruence between morphologic and molecular characters to search for discontinuities on these features across geography to delimit species within the genus, testing the aforementioned hypothesis. Morphological analyses, both qualitative and quantitative, showed that all characters are polymorphic throughout the geographic range of the genus. Results from phylogenetic analyses of cytochrome b (Cytb) data showed the topology (Misiones (Minas Gerais (Sao Paulo, Rio de Janeiro))), which is better explained as geographic rather than taxonomic variation, based on low values of genetic divergence observed between all specimens. Therefore, we reject the hypothesis of a polytypic Abrawayaomys, synonymizing A. chebezi to A. ruschii, and do not recognize specimens from Minas Gerais state as representing a distinct species.

Abrawayaomys é um gênero endêmico da Floresta Atlântica que apresenta características crânio-dentais exclusivas dentre os roedores sigmodontíneos. Dados recentes sugerem a existência de duas espécies distintas de Abrawayaomys, A. ruschii (com ocorrência nos estados brasileiros do Espírito Santo, Rio de Janeiro e São Paulo) e A. chebezi (ocorrendo na Província de Misiones, Argentina, e no Estado do Paraná, Brasil), além de uma possível espécie não descrita (espécimes do Estado de Minas Gerais, Brasil). No presente estudo, com base em uma série expressiva de espécimes recentemente coletados, avaliamos a congruência entre caracteres morfológicos e moleculares buscando encontrar possíveis descontinuidades discretas associadas à geografia, a fim de delimitar as espécies do gênero com base na hipótese taxonômica acima mencionada. As análises morfológicas qualitativas e quantitativas mostraram que todos os caracteres são polimórficos ao longo da geografia e não apresentam descontinuidades discretas que favoreçam o reconhecimento de distintas entidades taxonômicas. Os resultados das análises filogenéticas a partir de sequências de cytb mostraram a seguinte topologia (Misiones (Minas Gerais (São Paulo, Rio de Janeiro))), que é melhor explicada como uma variação geográfica e não taxonômica, com base nos baixos valores de divergência genética observados entre todos os espécimes. Portanto, nós rejeitamos a hipótese de um gênero Abrawayaomys politípico, reconhecendo A. chebezi como sinônimo júnior de A. ruschii e não reconhecendo os espécimes de Minas Gerais como uma nova espécie.