Geoclimatic drivers of diversification in the largest arid and semi-arid environment of the Neotropics: Perspectives from phylogeography.

The South American Dry Diagonal, also called the Diagonal of Open Formations, is a large region of seasonally dry vegetation extending from northeastern Brazil to northern Argentina, comprising the Caatinga, Cerrado, and Chaco subregions. A growing body of phylogeography literature has determined that a complex history of climatic changes coupled with more ancient geological events has produced a diverse and endemic-rich Dry Diagonal biota. However, the exact drivers are still under investigation, and their relative strengths and effects are controversial. Pleistocene climatic fluctuations structured lineages via vegetation shifts, refugium formation, and corridors between the Amazon and Atlantic forests. In some taxa, older geological events, such as the reconfiguration of the São Francisco River, uplift of the Central Brazilian Plateau, or the Miocene inundation of the Chaco by marine incursions, were more important. Here, we review the Dry Diagonal phylogeography literature, discussing each hypothesized driver of diversification and assessing degree of support. Few studies statistically test these hypotheses, with most support drawn from associating encountered phylogeographic patterns such as population structure with the timing of ancient geoclimatic events. Across statistical studies, most hypotheses are well supported, with the exception of the Pleistocene Arc Hypothesis. However, taxonomic and regional biases persist, such as a proportional overabundance of herpetofauna studies, and the under-representation of Chaco studies. Overall, both Pleistocene climate change and Neogene geological events shaped the evolution of the Dry Diagonal biota, though the precise effects are regionally and taxonomically varied. We encourage further use of model-based analyses to test evolutionary scenarios, as well as interdisciplinary collaborations to progress the field beyond its current focus on the traditional set of geoclimatic hypotheses.

Species richness and distribution patterns of the snake fauna of Rio Grande do Norte state, northeastern Brazil.

The Neotropics are one of the richest regions in biodiversity globally. Still, much remains unknown about the mechanisms and processes responsible for the accumulation of species in this region. Among the many limitations on our current knowledge on the region's biodiversity, understanding of community composition and species distributions is limited and greatly biased in many Brazilian regions. We present information on species composition, habitat use, geographic distribution, taxonomic accounts, and conservation of snakes from Rio Grande do Norte state, Northeastern Brazil. We compiled, from primary and literature data, 851 snake records from seven families and 47 species, with five new records for the state. Species are mainly terrestrial and semi-arboreal and associated with at least six vegetation types from Caatinga and Atlantic Forest domains. None of the species is listed in threatened categories of IUCN, while two species are listed in the Brazilian Threatened Fauna list. Our data covers 32.34% of the state's area, a consequence of locally limited inventories and lack of long-term studies on snakes' fauna. The richest areas within the state are near large cities, which lack protected areas for the species they harbor, and highlights the necessity of protective policies and conservation actions.

Cryptic diversity and ancient diversification in the northern Atlantic Forest Pristimantis (Amphibia, Anura, Craugastoridae).

The Neotropical region is known both for its megadiverse fauna and for the significant deficiency of our knowledge on species limits. The Amazon and Atlantic Forest are the two most diverse and large rainforests in South America, and they harbor many groups of sister species and sister genera. The frog genus Pristimantis is the most speciose genus of terrestrial vertebrates with 546 species, but only three of them occur in the Atlantic forest. Herein, we investigate the diversification history and phylogenetic relationship among the Atlantic Forest Pristimantis lineages in a spatial-temporal framework, using mitochondrial and nuclear genes. Our results reveal a remarkable hidden diversity, with nine highly structure lineages that may correspond to undescribed species, with many cases of sympatry among these divergent lineages. Atlantic forest Pristimantis form a monophyletic group that started to diversify over 40 million years ago. This ancient group shows diversification events that remount the early bursts of the Atlantic Forest diversification history, as well as lineage diversification likely resulting from recent Pleistocene climatic fluctuations. Future work must concentrate in comparing these lineages under an integrative framework including morphology, advertisement calls and other ecology traits to confidently delimit species of Pristimantis in the Atlantic Forest.

Morphological characterization and taxonomic key of tadpoles (Amphibia: Anura) from the northern region of the Atlantic Forest / Caracterização morfológica e chave taxonômica de girinos (Amphibia: Anura) da região norte da Mata Atlântica

Abstract: Although anuran tadpoles are widely distributed and abundant in tropical aquatic habitats, there is a lack of taxonomic keys for the Atlantic Forest. Herein, we developed a dichotomous key for identifying the tadpoles for all species with known larval phase and already recorded in the Atlantic Forest north of the São Francisco River. We analyzed discrete characteristics of 1,042 tadpoles encompassing 63 species of 28 genera from 32 localities. The user-friendly key includes illustration and pictures, and it is a significant step towards improving our knowledge of tadpoles of the Atlantic Forest.

Resumo: Embora os girinos de anuros sejam amplamente distribuídos e abundantes em habitats aquáticos tropicais, não há chaves taxonômicas suficientes para as espécies da Mata Atlântica. Aqui, desenvolvemos uma chave dicotômica para identificar os girinos de todas as espécies com fase larval conhecida e já registradas nesse bioma, ao norte do rio São Francisco. Nós analisamos características discretas de 1.042 girinos pertencentes a 63 espécies (28 gêneros) de 32 localidades. Esta chave de identificação inclui ilustrações e imagens, sendo um passo significativo para um melhor conhecimento dos girinos da Mata Atlântica.

The tadpole of Scinax camposseabrai (Bokermann) (Amphibia, Anura, Hylidae).

The treefrog Scinax camposseabrai (Bokermann) is endemic to the Brazilian semiarid region and known from the municipalities of Maracás, Igaporã and Curaçá, in the state of Bahia, and from the municipality of Matias Cardoso, northern Minas Gerais state, Brazil (Frost 2019). It was removed from the synonymy of Scinax x-signatus (Spix), recognized as a valid species, and placed in the S. ruber clade (sensu Faivovich et al. 2005) by Caramaschi Cardoso (2006). Taxonomic changes proposed by Duellman et al. (2016) for the genus Scinax were discussed by Lourenço et al. (2016) and Faivovich et al. (2018), and we follow here their suggestion to consider Ololygon and Julianus (erected for the S. uruguayus group) as synonyms of Scinax. This large genus Scinax currently would include 123 species (Frost 2019), many of which have had their larval morphology formerly described. Here, we describe the external morphology of the previously unknown tadpoles of S. camposseabrai.

Climatic suitability, isolation by distance and river resistance explain genetic variation in a Brazilian whiptail lizard.

Spatial patterns of genetic variation can help understand how environmental factors either permit or restrict gene flow and create opportunities for regional adaptations. Organisms from harsh environments such as the Brazilian semiarid Caatinga biome may reveal how severe climate conditions may affect patterns of genetic variation. Herein we combine information from mitochondrial DNA with physical and environmental features to study the association between different aspects of the Caatinga landscape and spatial genetic variation in the whiptail lizard Ameivula ocellifera. We investigated which of the climatic, environmental, geographical and/or historical components best predict: (1) the spatial distribution of genetic diversity, and (2) the genetic differentiation among populations. We found that genetic variation in A. ocellifera has been influenced mainly by temperature variability, which modulates connectivity among populations. Past climate conditions were important for shaping current genetic diversity, suggesting a time lag in genetic responses. Population structure in A. ocellifera was best explained by both isolation by distance and isolation by resistance (main rivers). Our findings indicate that both physical and climatic features are important for explaining the observed patterns of genetic variation across the xeric Caatinga biome.

Multilocus Phylogeography of the Treefrog Scinax eurydice (Anura, Hylidae) Reveals a Plio-Pleistocene Diversification in the Atlantic Forest.

We aim to evaluate the genetic structure of an Atlantic Forest amphibian species, Scinax eurydice, testing the congruence among patterns identified and proposed by the literature for Pleistocene refugia, microrefugia, and geographic barriers to gene flow such as major rivers. Furthermore, we aim to evaluate predictions of such barriers and refugia on the genetic structure of the species, such as presence/absence of dispersal, timing since separation, and population expansions/contractions. We sequenced mitochondrial and nuclear genetic markers on 94 tissue samples from 41 localities. We inferred a gene tree and estimated genetic distances using mtDNA sequences. We then ran population clustering and assignment methods, AMOVA, and estimated migration rates among populations identified through mtDNA and nDNA analyses. We used a dated species tree, skyline plots, and summary statistics to evaluate concordance between population's distributions and geographic barriers and Pleistocene refugia. Scinax eurydice showed high mtDNA divergences and four clearly distinct mtDNA lineages. Species tree and population assignment tests supported the existence of two major clades corresponding to northeastern and southeastern Atlantic Forest in Brazil, each one composed of two other clades. Lineage splitting events occurred from late Pliocene to Pleistocene. We identified demographic expansions in two clades, and inexistent to low levels of migrations among different populations. Genetic patterns and demographic data support the existence of two northern Refuge and corroborate microrefugia south of the Doce/Jequitinhonha Rivers biogeographic divide. The results agree with a scenario of recent demographic expansion of lowland taxa. Scinax eurydice comprises a species complex, harboring undescribed taxa consistent with Pleistocene refugia. Two rivers lie at the boundaries among populations and endorse their role as secondary barriers to gene flow.

External morphology and oral cavity of the tadpole of Trachycephalus atlas Bokermann, 1966 (Amphibia, Anura, Hylidae).

The Neotropical genus Trachycephalus Tschudi currently comprises 14 species distributed in lowlands of Mexico, Central and South America east of the Andes, south until northern Argentina (Frost 2014) and throughout Brazil (IUCN 2014). Seven species of the genus have tadpoles formerly described: T. coriaceus (Peters) (Schiesari & Moreira 1996; Lescure et al. 1996), T. cunauaru Gordo, Toledo, Suárez, Kawashita-Ribeiro, Ávila, Morais & Nunes (Grillitsch 1992 as Phrynohyas resinifictrix according to Gordo et al. 2013), T. jordani (Stejneger & Test) (McDiarmid & Altig 1989-1990), T. mesophaeus (Hensel) (Lutz 1973; Carvalho-e-Silva et al. 2002; Prado et al. 2003), T. nigromaculatus Tschudi (Wogel et al. 2000), T. resinifictrix (Goeldi) (Hero 1990; Schiesari et al. 1996), and T. typhonius (Linnaeus) (Pyburn 1967; Duellman 1970; Schiesari et al. 1996). The oral cavity is described only for T. cunauaru (Grillitsch 1992), T. resinifictrix (Schiesari et al. 1996), and T. typhonius (Schiesari et al. 1996; Fabrezi & Vera 1997).

Anurans from the Middle Jaguaribe River Region, Ceará State, Northeastern Brazil / Anuros da região do Médio Rio Jaguaribe, estado do Ceará, Nordeste do Brasil

The Middle Jaguaribe River region is a poorly sampled area in the Caatingas domain, located in the eastern Ceará State, northeastern Brazil. The Brazilian government agencies considered this region as a priority area for conservation and inventories. In order to fill this biodiversity knowledge gap, we conducted a ten-day rapid inventory of the anuran fauna from April 11 to 20, 2014, surveying different physiognomies of the region. We recorded 19 anuran species belonging to five families: Bufonidae (2), Hylidae (5), Leptodactylidae (9), Microhylidae (2) and Odontophrynidae (1). Most inventories of Caatinga amphibians published to date have been conducted inside protected areas and/or of high altitude (mesic areas known as "brejos de altitude"). The list we present herein contributes to the knowledge of lowland Caatinga sites outside protected areas. We discuss our results in light of taxonomic and geographic features of the anurans sampled.

A Região do Médio Rio Jaguaribe é uma área pobremente amostrada no domínio das Caatingas, localizada no leste do Estado do Ceará, Nordeste do Brasil. O Ministério do Meio Ambiente considera esta região como uma área prioritária para conservação e realização de inventários. Com o objetivo de preencher esta lacuna do conhecimento sobre a biodiversidade, nós conduzimos um inventário rápido da anurofauna de dez dias de 11 a 20 de Abril de 2014, amostrando diferentes fisionomias da região. Nós registramos 19 espécies de anfíbios anuros pertencentes a cinco famílias: Bufonidae (2), Hylidae (5), Leptodactylidae (9), Microhylidae (2) e Odontophrynidae (1). A maioria dos inventários de anfíbios na Caatinga publicados até o presente momento foram conduzidos em áreas de proteção e/ou de áreas de altitude (áreas mésicas conhecidas como “Brejos de Altitude”). A presente lista contribui para o conhecimento de áreas de baixada da Caatinga fora das áreas protegidas. Nós discutimos os resultados è luz de características taxonômicas e biogeográficas dos anuros amostrados.

Herpetofauna of protected areas in the Caatinga III: The Catimbau National Park, Pernambuco, Brazil / Herpetofauna em unidades de conservação da Caatinga III: Parque Nacional do Catimbau, Pernambuco, Brasil

Despite the increase in herpetofaunal inventories in the Caatinga biome, information for many areas is still lacking and new surveys are required. We conducted a 30-day inventory of the herpetofauna of the Catimbau National Park, Pernambuco State, Brazil. Thirty-seven pitfall trap arrays composed of 4 buckets each, along with glue traps and active searches were used to sample local herpetofaunal diversity. We recorded 21 species of frogs, 25 lizards, 11 snakes, and 1 chelonian. All sampling methods contributed significantly to achieve the amphibian and reptile diversity recovered in the inventory. Rarefaction curves and richness estimators suggest that local biodiversity is still underestimated. We attempted to show the great potential of Catimbau National Park, characterized by the richest herpetofauna surveyed in a core region of the biome, along with the presence of endemic species such as the worm snake Amphisbaena supranumeraria and the limbless lizard Scriptosaura catimbau, underscoring the importance of the area for the conservation and maintenance of the Caatinga herpetofauna biodiversity.

Apesar do crescente aumento nos inventários de herpetofauna no bioma Caatinga, ainda faltam informações para muitas áreas e novos estudos são necessários. O Parque Nacional do Catimbau, Pernambuco, Brasil, foi inventariado entre os meses de março e abril de 2013 totalizando 30 dias de amostragem, para descrever a herpetofauna local. Foram utilizados 37 pontos amostrais de armadilhas de interceptação e queda, onde cada ponto era composto por quatro baldes conectados por cercas-guia. Armadilhas de cola e procura ativa também foram métodos utilizados para amostrar a diversidade de anfíbios e répteis. Foram registradas 21 espécies de anfíbios, 25 espécies de lagartos, 11 espécies de serpentes e uma tartaruga. Todos os métodos de amostragem contribuíram para o inventário. As curvas de rarefação e os estimadores de riqueza sugerem que a diversidade local ainda está subestimada. Nós apresentamos o grande potencial do Parque Nacional do Catimbau, caracterizado pela mais rica herpetofauna inventariada na região central do bioma, e tambémpela presença de espécies endêmicas como Amphisbaena supranumeraria e Scriptosaura catimbau, evidenciando a importância da área para a manutenção e conservação da herpetofauna da Caatinga.

Conservation genetics of maned wolves in a highly impacted area of the Brazilian Cerrado biome.

Maned wolves are large canids currently considered vulnerable to extinction due to habitat loss. They are still commonly found within the urban mesh inside the Brazilian Federal District (Distrito Federal--DF), in nearby Protected Areas (PAs), and in surrounding farms. We evaluated the genetic diversity of maned wolves in three PAs of the DF, using both invasive and noninvasive techniques to obtain DNA that was later amplified for five microsatellite markers. We sampled 23 wolves: 10 with the noninvasive method, three captured in traps, six road-killed, and four rescued in urban areas. In Águas Emendadas Ecological Station (ESECAE) we also used samples from six specimens captured between 1997 and 1998 for a temporal comparison. For maned wolves, non-invasive techniques are affordable and easier to conduct in the field, while laboratory costs are much lower for invasive samples. Hence, a sampling strategy combining both techniques may provide an interesting approach for molecular ecology studies requiring comprehensive coverage of local individuals. On the basis of such integrated sampling scheme, our analyses indicated that none of the investigated populations currently present deviations from Hardy-Weinberg expectations or indication of inbreeding. Furthermore, in ESECAE there was no reduction in genetic diversity during the last 9 years. Overall, maned wolves did not present evidence of genetic structuring among the three sampled PAs. These results thus indicate that individual exchange among PAs is still occurring at sufficient rates to avoid differentiation, and/or that the recent fragmentation in the region has not yet produced measurable effects in the genetic diversity of maned wolves.