Comparative Phylogeography of the Atlantic Forest Endemic Sloth (Bradypus torquatus) and the Widespread Three-toed Sloth (Bradypus variegatus) (Bradypodidae, Xenarthra)

Taxonomic revision of maned sloths, subgenus Bradypus (Scaeopus), Pilosa, Bradypodidae, with revalidation of Bradypus crinitus Gray, 1850

We present a taxonomic revision of maned sloths, subgenus Bradypus (Scaeopus), a taxon endemic to the Brazilian Atlantic Forest and currently composed of a single species, the vulnerable Bradypus torquatus. Our review is based on coalescent species delimitation analyses using mitochondrial and nuclear DNA, morphological analyses, and field observations. Our integrative approach demonstrates that two species of maned sloth can be recognized: the northern maned sloth (Bradypus torquatusIlliger, 1811) occurring in the Brazilian states of Bahia and Sergipe, and the southern maned sloth (Bradypus crinitusGray, 1850), occurring in Rio de Janeiro and Espirito Santo states. The two species diverged in the Early Pliocene and are allopatrically distributed. We discuss the biogeographic pattern of the two maned sloth species, comparing it with other Atlantic Forest mammals. We also suggest that the conservation status of both maned sloths needs to be reassessed after this taxonomic rearrangement.

Geographic restriction, genetic divergence, and morphological disparity in the Brazilian Atlantic Forests: Insights from Leposoma lizards (Gymnophthalmidae, Squamata)

Lineage differentiation, long-term persistence, and range limitation promote high levels of phylogenetic and phylogeographic endemisms and likely underlie the abundant morphologically cryptic diversity observed in the Brazilian Atlantic Forests (AF). We explore lineage differentiation and range restriction in the AF and ask if genetic divergence and morphological disparity are correlated by integrating coalescent-based species delimitation, molecular phylogenetic, and morphological analyses in the lizard genus Leposoma. We present the first species tree for Leposoma and of their tribe, the Ecpleopodini. The analyses are based on the largest dataset ever assembled for Leposoma in terms of number of species (all represented), genetic markers (12 loci), and geographic coverage (~2,500 km). The exercise allows us to robustly delimit species within the genus and phylogeographic lineages within all species. We find support for the monophyly of the genus and for the recognition of a yet undescribed species around the Baía de Todos-os-Santos, in the state of Bahia; this form is distinct from all other congeners, both genetically and morphologically. We find that L. baturitensis, from the northeastern state of Ceará, is basal to the genus - and sister to a clade of six species restricted to the AF across the eastern coast of Brazil. Relationships within this coastal clade are ((((L. annectans, Leposoma sp.), L. scincoides), L. puk) (L. nanodactylus, L. sinepollex)). Phylogenetic and phylogeographic analyses, together with precise distribution data, allowed us to update the ranges of species and phylogeographic lineages. We reveal pervasive geographic restriction of divergent lineages in Leposoma at and below species level and discuss how forest refuges and rivers might have contributed to it. We find that morphological disparity lags behind genetic divergence in the genus because although they are correlated, the first accumulates at a much slower rate than the latter. We hope to encourage new studies in the area of AF north of the Doce river; phylogeographic sampling in that region has been much less common relative to southern sites, yet it may hold the key to several important processes defining biodiversity patterns in eastern Brazil. This appears to specially apply to processes underlying geographic restriction of morphologically cryptic, yet genetic divergent lineages, as the case of Leposoma.

Sloths host Anhanga virus-related phleboviruses across large distances in time and space

Sloths are genetically and physiologically divergent mammals. Phleboviruses are major arthropod‐borne viruses (arboviruses) causing disease in humans and other animals globally. Sloths host arboviruses, but virus detections are scarce. A phlebovirus termed Anhanga virus (ANHV) was isolated from a Brazilian Linnaeus's two‐toed sloth (Choloepus didactylus) in 1962. Here, we investigated the presence of phleboviruses in sera sampled in 2014 from 74 Hoffmann's two‐toed (Choloepus hoffmanni, n = 65) and three‐toed (Bradypus variegatus, n = 9) sloths in Costa Rica by broadly reactive RT‐PCR. A clinically healthy adult Hoffmann's two‐toed sloth was infected with a phlebovirus. Viral load in this animal was high at 8.5 × 10⁷ RNA copies/ml. The full coding sequence of the virus was determined by deep sequencing. Phylogenetic analyses and sequence distance comparisons revealed that the new sloth virus, likely representing a new phlebovirus species, provisionally named Penshurt virus (PEHV), was most closely related to ANHV, with amino acid identities of 93.1%, 84.6%, 94.7% and 89.0% in the translated L, M, N and NSs genes, respectively. Significantly more non‐synonymous mutations relative to ANHV occurred in the M gene encoding the viral glycoproteins and in the NSs gene encoding a putative interferon antagonist compared to L and N genes. This was compatible with viral adaptation to different sloth species and with micro‐evolutionary processes associated with immune evasion during the genealogy of sloth‐associated phleboviruses. However, gene‐wide mean dN/dS ratios were low at 0.02–0.15 and no sites showed significant evidence for positive selection, pointing to comparable selection pressures within sloth‐associated viruses and genetically related phleboviruses infecting hosts other than sloths. The detection of a new phlebovirus closely‐related to ANHV, in sloths from Costa Rica fifty years after and more than 3,000 km away from the isolation of ANHV confirmed the host associations of ANHV‐related phleboviruses with the two extant species of two‐toed sloths.

Neither barriers nor refugia explain genetic structure in a major biogeographic break: phylogeography of praying mantises in the Brazilian Atlantic Forest

The Atlantic Forest is one of the world's top biodiversity hotspots, but the diversification processes of its biota are still poorly known, with competing models attributing dominant roles to either Quaternary climatic changes or geographic barriers. Many studies identify the Doce river as a major phylogeographic break, but the reasons for this phenomenon are highly debated. Here we test the predictions of the refugial and barrier models for a common species of praying mantis, Miobantia fuscata, focusing in the areas immediately south and north of the Doce river. Our analyses show high intraspecific genetic diversity, deep coalescence times and no evidence for recent population expansion. Phylogeographic structure is inconsistent with a refugial hypothesis. Significant gene flow between northern and southern populations also conflicts with a strong role for geographic barriers. This study highlights the need for considering invertebrate taxa to infer recent landscape changes, and points towards a more complex picture of genetic diversification in the Atlantic Forest.

FIRST RECORD OF HEMATOLOGIC VALUES IN FREE-LIVING AND CAPTIVE MANED SLOTHS (BRADYPUS TORQUATUS; XENARTHA, BRADYPODIDAE)

Bradypus torquatus is a rare and endemic sloth species from the Atlantic Forest, Brazil. Due to a lack of medical information including hematologic reference parameters for the species, hematologic baseline values were determined using samples from 14 clinically healthy B. torquatus , under captive (n = 7) and free-living (n = 7) conditions in Bahia State, Brazil. Additionally, the morphology of the blood cells is presented, with a demonstration that the Barr body chromosome may assist with sex determination of the species. The Barr body chromosome was present in all seven females and absent in all males. Many erythrocytes were approximately the size of small lymphocytes, with red blood cells exhibiting anisocystosis, normochromia, and apparent macrocytosis, compared with domestic animals. This study provides the first published hematologic values and cell morphology for B. torquatus . However, further studies are suggested using an automated hematology analyzer with larger sample sizes so that reference intervals may be established and hematologic values better understood for sex, habitat type, and age cohorts.

Primeiro registro de Amblyomma geayi (Acari: ixodidae) em preguiça (Bradypus variegatus) no estado do Acre, Amazônia Ocidental: relato de caso

RESUMO O Amblyomma geayi é um carrapato da família Ixodidae, encontrado principalmente em mamíferos e aves silvestres de regiões tropicais da América do Sul. Descreve-se a ocorrência de um carrapato ixodídeo da espécie A. geayi, encontrado em uma preguiça (Bradypus variegatus) proveniente do Parque Zoobotânico da Universidade Federal do Acre, Rio Branco, Acre, Amazônia Ocidental.

Delimiting areas of endemism through kernel interpolation

We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE), based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units.

The distributional ecology of the maned sloth: environmental influences on its distribution and gaps in knowledge

The maned sloth Bradypus torquatus (Pilosa, Bradypodidae) is endemic to a small area in the Atlantic Forest of coastal Brazil. It has been listed as a threatened species because of its restricted geographic range, habitat loss and fragmentation, and declining populations. The major objectives of this study were to estimate its potential geographic distribution, the climatic conditions across its distributional range, and to identify suitable areas and potential species strongholds. We developed a model of habitat suitability for the maned sloth using two methods, Maxent and Mahalanobis Distance, based on 42 occurrence points. We evaluated environmental variable importance and the predictive ability of the generated distribution models. Our results suggest that the species distribution could be strongly influenced by environmental factors, mainly temperature seasonality. The modeled distribution of the maned sloth included known areas of occurrence in the Atlantic Forest (Sergipe, Bahia, Espírito Santo, and Rio de Janeiro), but did not match the observed distributional gaps in northern Rio de Janeiro, northern Espírito Santo or southern Bahia. Rather, the model showed that these areas are climatically suitable for the maned sloth, and thus suggests that factors other than climate might be responsible for the absence of species. Suitable areas for maned sloth were located mainly in the mountainous region of central Rio de Janeiro throughout Espírito Santo and to the coastal region of southern Bahia. We indicate 17 stronghold areas and recommended survey areas for the maned sloth. In addition, we highlight specific areas for conservation, including the current network protected areas. Our results can be applied for novel surveys and discovery of unknown populations, and help the selection of priority areas for management and conservation planning, especially of rare and relatively cryptic species directed associated with forested habitats.

Chromosome evolution in Xenarthra: new insights from an ancient group

The Magnaorder Xenarthra is one of the four main supraordinal eutherian clades, together with Afrotheria, Euarchontoglires and Laurasiatheria. Xenarthra is an eminently Central and South American group of special interest in phylogenetic studies due to its possible position at the base of the eutherian tree. The use of modern cytogenetic techniques in some species of Xenarthra has provided important insights into the karyotypic evolution of mammals. Nevertheless, chromosome analyses in the group are still restricted, with only a few individuals of each species studied and karyotype descriptions mostly without banding patterns. In addition, it is likely that still unknown species exist and that the chromosome variability in the group is underestimated. We present a review of the currently available data on Xenarthra chromosomes and genomes and on the impact that their study has had in the understanding of mammalian genome evolution. It is clear that further cytogenetic analyses in Xenarthra, including banding patterns and molecular approaches, are likely to help in the identification of new species, reveal still undetected chromosome variations, provide information to support conservation strategies planning, and greatly contribute to a better understanding of mammalian genome evolution.

Phylogeography of the endangered rosewood Dalbergia nigra (Fabaceae): insights into the evolutionary history and conservation of the Brazilian Atlantic Forest

The Brazilian rosewood (Dalbergia nigra) is an endangered tree endemic to the central Brazilian Atlantic Forest, one of the world's most threatened biomes. The population diversity, phylogeographic structure and demographic history of this species were investigated using the variation in the chloroplast DNA (cpDNA) sequences of 185 individuals from 19 populations along the geographical range of the species. Fifteen haplotypes were detected in the analysis of 1297 bp from two non-coding sequences, trnV-trnM and trnL. We identified a strong genetic structure (F(ST)=0.62, P<0.0001), with a latitudinal separation into three phylogeographic groups. The two northernmost groups showed evidence of having maintained historically larger populations than the southernmost group. Estimates of divergence times between these groups pointed to vicariance events in the Middle Pleistocene (ca. 350,000-780,000 years ago). The recurrence of past climatic changes in the central part of the Atlantic forest, with cycles of forest expansion and contraction, may have led to repeated vicariance events, resulting in the genetic differentiation of these groups. Based on comparisons among the populations of large reserves and small, disturbed fragments of the same phylogeographic group, we also found evidence of recent anthropogenic effects on genetic diversity. The results were also analysed with the aim of contributing to the conservation of D. nigra. We suggest that the three phylogeographic groups could be considered as three distinct management units. Based on the genetic diversity and uniqueness of the populations, we also indicate priority areas for conservation.

Otoacariasis due to Edentalges bradypus Fonseca 1954 (Acari; Psoroptidae) infestation in the brown-throated three-toed sloth Bradypus variegatus from Brazil

The aim of this paper is to report the first description of gross pathological aspects of otoacariasis due to Edentalges bradypus Fonseca 1954 (Acari; Psoroptidae) infestation in the brown-throated three-toed sloth Bradypus variegatus Schinz, 1825 (Xenarthra; Bradypodidae) in Brazil. Mites were collected from massive skin crusts seen in both external ear canals and around both eyes of an extremely debilitated advanced-aged female sloth brought to the Wildlife Care Section of Universidade Estácio de Sá, Rio de Janeiro, Brazil.

Identifying management units in non-endangered species: the example of the sloth Bradypus variegatus Schinz, 1825

In this study we propose the analysis of genetic diversity of the common three-toed sloth, Bradypus variegatus, in an attempt to understand population structure, identify divergent intraspecific units, and contribute to the knowledge of biodiversity in the neotropical forests. We analyzed a 387 bp segment of the mitochondrial DNA control region in 28 individuals distributed in different localities of both Atlantic and Amazon forests. Our results demonstrated that the genetic diversity of B. variegatus is distributed in six management units, MUs. The observed MUs encompass six phylogenetic lineages and represent respectively north and south regions of Atlantic forest, three regions within the Amazon forest, and a transition region between these two biomes. Considering the fact that these MUs are concordant with phylogroups and endemism areas already described for other vertebrate species, we can say that the study of B. variegatus, a widely distributed and not endangered species, can help to identify areas for conservation biology purposes in neotropical rain forests.