How many species of mammals are there in Brazil? New records of rare rodents (Rodentia: Cricetidae: Sigmodontinae) from Amazonia raise the current known diversity

TE, Solari S, Colmenares-Pinzon J, Nivelo C, Rodríguez Herrera B, Merino W, Medina CE, Murillo-García O, Pardiñas UF. Systematics and diversification of the Ichthyomyini (Cricetidae, Sigmodontinae) revisited: evidence from molecular, morphological, and combined approaches

Ichthyomyini, a morphologically distinctive group of Neotropical cricetid rodents, lacks an integrative study of its systematics and biogeography. Since this tribe is a crucial element of the Sigmodontinae, the most speciose subfamily of the Cricetidae, we conducted a study that includes most of its recognized diversity (five genera and 19 species distributed from southern Mexico to northern Bolivia). For this report we analyzed a combined matrix composed of four molecular markers (RBP3, GHR, RAG1, Cytb) and 56 morphological traits, the latter including 15 external, 14 cranial, 19 dental, five soft-anatomical and three postcranial features. A variety of results were obtained, some of which are inconsistent with the currently accepted classification and understanding of the tribe. Ichthyomyini is retrieved as monophyletic, and it is divided into two main clades that are here recognized as subtribes: one to contain the genus Anotomys and the other composed by the remaining genera. Neusticomys (as currently recognized) was found to consist of two well supported clades, one of which corresponds to the original concept of Daptomys. Accordingly, we propose the resurrection of the latter as a valid genus to include several species from low to middle elevations and restrict Neusticomys to several highland forms. Numerous other revisions are necessary to reconcile the alpha taxonomy of ichthyomyines with our phylogenetic results, including placement of the Cajas Plateau water rat (formerly Chibchanomys orcesi) in the genus Neusticomys (sensu stricto), and the recognition of at least two new species (one in Neusticomys, one in Daptomys). Additional work is necessary to confirm other unanticipated results, such as the non-monophyletic nature of Rheomys and the presence of a possible new genus and species from Peru. Our results also suggest that ichthyomyines are one of the main Andean radiations of sigmodontine cricetids, with an evolutionary history dating to the Late Miocene and subsequent cladogenesis during the Pleistocene.

Using Remote Sensing Data and Species–Environmental Matching Model to Predict the Potential Distribution of Grassland Rodents in the Northern China

An increase in grassland rodent pests in China has seriously affected grassland ecological environments and the development of husbandry. Here, we used remote sensing data and a species–environmental matching model to predict the potential spatial distribution of the five major rodent pest species (Microtus, Citellus, Myospalax, Meriones, Ochotona) in northern China, and examined how the predicted suitability of the area depends on environmental variables. The results were consistent and significant, better than random, and close to optimal. Meriones and Microtus had the largest areas of High Suitability and Moderate Suitability with regard to environmental conditions. The combination analysis of areas of Moderate Suitability and High Suitability showed that for 66% of the total area, conditions were suitable for just one rodent species, while conditions suitable for two and three kinds of rodents accounted for 31% and 3%, respectively. Altitude, land surface temperature in winter (November, December, February) and summer (May, June, July), vegetation cover in summer (July, August), and precipitation from spring to summer (April, May, June) determined the spatial distribution of grassland rodents. Our findings provide a powerful and useful methodological tool for tracking the five major rodent pest species in northern China and for future management measures to ensure grassland ecological environment security.

Natural history museums and zoological collections of São Paulo State

Abstract Scientific collections constitute a valuable source for contributions to scientific research and the training of human resources in systematics, but also other areas of biological knowledge. In this contribution, we intend to discuss these advancements in collections and the role played by FAPESP in sponsoring them, as well as a general overview of the zoological collections in São Paulo state. We also aim to stress the importance of zoological collections and the need for continuous logistic and financial support from institutions and research agencies to maintain and develop these unique repositories of biodiversity. From 1980 to the present, FAPESP supported 118 research projects focused on several areas of zoology that are directly or indirectly associated with collections. There is a constant growth in the number of projects, and the financial support provided by FAPESP through the Biota Program was paramount for the advancement of our knowledge of biodiversity in Brazil. Parallel to the scientific advances, but not less important, this support allowed curators to increase the number of specimens, and to organize, maintain and digitize them in these valuable and irreplaceable collections. Regarding the lack of new taxonomists, it is essential that FAPESP and universities in São Paulo encourage the formation of new academics in zoological groups where specialists are rare. Considering the investment provided by FAPESP, it is quite important that the institutions that benefited from these resources took greater responsibility to safeguard these collections, and they should consider including resources on their budgets to obtain safety certificates, ensuring their permanence for many generations to come. Zoological collections are a heritage of humanity and are essential not only for the improvement of our knowledge of biodiversity but also with direct applications, among other services provided by these biological resources. It is important that research and teaching institutions in São Paulo that house specimens under their care start to value more this important patrimony and this heritage, as these collections represent the most valuable testimony of our impressive biodiversity, records of our past, and windows to our future, essential to our academic, scientific, cultural and social sovereignty.

Areas of endemism of small mammals are underprotected in the Atlantic Forest

Atlantic Forest (AF) is amongst the most threatened forests in the world. To decide where conservation efforts should be focused to preserve species, assessment of ecological and biogeographic processes nowadays are crucial. Patterns of the distribution of organisms can provide an important source of information underlying the biogeographical history of a biota. Here, our main objective was to identify Areas of Endemism (AoE) for non-volant small mammals in the AF and to investigate if those AoE are covered by protected areas. We performed quantitative and qualitative approaches to delimit AoE and calculated the area overlaid by Conservation Units (CU) within each AoE. Our results supported the recognition of seven AoE for small mammals in the AF, which largely are congruent with previous studies undertaken on other organisms, thereby highlighting the importance of those regions as hotspots of endemism. Most of the AoE recovered in the present study have less than 12% of their territory covered by forest remnants, and less than 11% of their entire range is under legal protection. These findings bring to light an important discussion on how information pertaining to the representativeness of CU within regions of high endemicity could help to identify areas in need of urgent protection within a threatened biodiversity hotspot.

A new species of Rhagomys (Rodentia, Sigmodontinae) from southeastern Ecuador

During a faunal survey in the foothills of the Ecuadoran Andes southwest of the Cordillera del Cóndor, a mouse of uncertain affinities was taken in a fishing net. Various external characters suggested that it was a member of the genus Rhagomys, previously unrecorded in Ecuador. Comparisons with the external, cranial, and dental morphology both of Rhagomys rufescens and R. longilingua identified a number of unique characters, including its long, narrow rostrum and incisive foramina and the reduced anterolingual conule on its M1 procingulum. We describe the mouse as a new species of Rhagomys; both its morphology and molecular analyses suggest that it is sister to R. longilingua. This record of Rhagomys in southern Ecuador extends the known distribution of the genus 700 km northward and adds yet another genus and species to Ecuador’s extensive list of rodent species.

First record of albinism in spiny rats of genus Proechimys (Rodentia: Echimyidae) from Western Amazon

Albinism is a rare condition in natural populations. One of the factors that would lead to higher allele frequency for the albino phenotype is bottleneck events, causing small population sizes and loss of genetic diversity. Here, we report the first record of albinism in one specimen of Proechimys gardneri from Porto Velho, Rondônia, Brazil. This is also the first record of albinism for the genus and for the family Echimyidae. We identified the specimen through morphology and confirmed the identification by 801 base pairs (bp) of mitochondrial marker cytochrome b (Cyt b). We also discuss the selection against albino phenotype in natural populations.

Updated and annotated checklist of recent mammals from Brazil

An updated and annotated checklist of mammals occurring in Brazil is presented. A total of 751 native species, distributed in 249 genera, 51 families and 11 orders were recorded to the country. The Brazilian mammalian fauna shows an elevated rate of endemism (30%; 223 species). Among the species evaluated by IUCN (668 species; 90%), a total of 80 (10.6% of total mammalian fauna) are Threatened, 28 (3.9%) are considered as Near Threatened, two species (0.3%) are presumable Extinct, 96 (12.8%) are considered with Deficient Data for conservation and 462 (61.6%) are considered as Least Concern. Fifteen new species were described since the last national compilation (published in 2017), which associated to new records to the country and synonimizations resulted in an increment of 30 species. Eight non-native species were introduced to the country, including the recently established Asiatic cervids Rusa unicolor (sambar) and Axis axis (chital). Seven native species (five primates and two hystricomorph rodents) have been translocated from their areas of natural occurrence to other areas inside the country.

A revision of Neusticomys peruviensis (Rodentia: Cricetidae) with the description of a new subspecies

Neusticomys peruviensis is a poorly known sigmodontine rodent of the tribe Ichthyomyini, represented in collections by only five specimens collected in five localities from lowland forests of central and southern Peru. Recent expeditions in Llanchama, in northern Peru, north of the Río Amazonas, and near Allpahuayo Mishana Natural Reserve (Loreto, Peru), were successful in obtaining three specimens of Neusticomys. Based on morphological and meristic data, we found the population at Llanchama is distinct from the allopatric populations of N. peruviensis, and other species of Neusticomys. A species distribution model also shows the population at Llanchama is not highly predicted by the set of variables of the known localities of N. peruviensis. However, sequence data from the mitochondrial cytochrome-b gene indicate that genetic distinctiveness is low. Because intraspecific variability is important to understand evolutionary and biogeographic processes, and in concordance with the polytypic species concept, we interpret the population at Llanchama to represent a new subspecies of N. peruviensis that we describe in this paper.