High levels of diversity uncovered in a widespread nominal taxon: continental phylogeography of the neotropical tree frog Dendropsophus minutus

Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km². One of them occupies an area of almost one million km² encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered.

Tetrodotoxin and its analogue 6-epitetrodotoxin in newts (Triturus spp.; Urodela, Salamandridae) from southern Germany

Tetrodotoxin (TTX) and its analogue 6-epitetrodotoxin (6-epiTTX) were quantitatively assayed in 59 newts representing four Triturus species (Triturus alpestris, Triturus cristatus, Triturus helveticus, Triturus vulgaris) from southern Germany by a post-column fluorescent-HPLC system. Both toxins were detected in only 15 specimens of the four species. The toxins levels varied considerably among individuals (TTX: 0.11-9.0microg/g; 6-epiTTX: 0.05-17.0microg/g). 6-epiTTX was found to be the major component.

Studies on the poisonous skin secretion of individual red bellied toads, Melanophryniscus montevidensis (Anura, Bufonidae), from Uruguay

Toads belonging to the genus Melanophryniscus contain toxic alkaloids in their skin. From six locations in south-eastern Uruguay 81 specimens of Melanophryniscusmontevidensis were collected. In whole animal methanolic extracts of individual specimens, alkaloids of the pumiliotoxin (PTX) group and indolizidines were identified by gas chromatography/mass spectrometry; the predominant component PTX 251D was assayed quantitatively. The PTX-content of the various toad populations was found to be highly variable among individual specimens as well as among the populations. Very high levels of PTX 251D were detected in toads of the western part of the collection area, whereas very low levels of this alkaloid were assayed in toads near the Brazilian border. Remarkably high concentrations of the non-alkaloid hydroquinone were found to be present in all toads. The analysis of extracts from 125 arthropod samples (Arachnida and Insecta, including termites, ants and beetles), which may represent a potential food source, revealed no alkaloids of the PTX group.

The genus Pseudis (Anura: Pseudidae) in Rio Grande do Sul, southern Brazil, with description of a new species

Abstract

A new species of Pseudis is described from São Francisco de Paula, Rio Grande do Sul, Brazil. It is known from the southern parts of the Serra Geral where it occurs in grassland, inhabiting permanent ponds and still-water zones of slow flowing creeks. It is characterized by a paired vocal sac and a bulbous thumb, considerably widened at the base. It is distinguished from P. minutus by its different call, body coloration, rounded snout, and a more robust body with shorter hindlimbs. Advertisement call, tadpole, and life history are described. The taxonomy of the family Pseudidae in Rio Grande do Sul is discussed, supporting the synonymy of Lysapsus mantidactylus and P. meridionalis with P. minutus.

Lack of bufadienolides in the skin secretion of red bellied toads, Melanophryniscus spp. (Anura, Bufonidae), from Uruguay

The South-American red bellied toads (Melanophryniscus spp.) belonging to the Bufonidae family contain toxic alkaloids in their skin, predominantly of the pumiliotoxin group. Whole animal methanolic extracts of individual specimens of three species (Melanophryniscus atroluteus, M. devincenzii, and M. montevidensis) were analyzed for the presence of toad specific bufadienolides and indolalkylamines (serotonin derivatives) by HPLC-electrospray (ESI)-MS-TOF. No bufadienolides, but few bufotenines, mainly dehydrobufotenine, were detected in the extracts in variable amounts. The concentration of the dehydrobufotenine in the extracts seems to be species specific. Whereas M. atroluteus and M. montevidensis contain very low or trace amounts, M. devincenzii specimens exhibit high concentrations of this indolalkylamine. In comparison, analysis of extracts from Bufo arenarum (Uruguay) and from B. bufo (Germany) confirmed the presence of bufadienolides as well as of bufotenine derivatives. Tadpoles of both species exhibited a different pattern: extracts from B. arenarum tadpoles contained only dehydrobufotenine, but those from B. bufo tadpoles bufotoxin and two alkylamines. Melanophryniscus toads appear not to be able to compensate the high variability of toxic skin alkaloids by producing defensive bufadienolides.

First record of Chaunus achavali (Anura, Bufonidae) from Rio Grande do Sul, Brazil, with a key for the identification of the species in the Chaunus marinus group

The bufonid toad Chaunus achavali, a recently described species known only from Uruguay, is recorded for Brazil. This species is morphologically similar to C. ictericus and C. arenarum, and several individuals were labeled in Brazilian scientific collections under these taxa. A lectotype of C. arenarum is designated. Additional field notes on C. achavali and a key for the identification of the species in the Chaunus marinus group are presented.

Novos registros na distribuição geográfica de anuros na floresta com araucária e considerações sobre suas vocalizações

Estudos envolvendo análises bioacústicas têm possibilitado a identificação de espécies pertencentes a grupos complexos, bem como a descrição e diferenciação de espécies crípticas. Recorrendo a esta ferramenta e com o objetivo de aumentar o conhecimento sobre a composição de espécies de anfíbios em áreas de Floresta com Araucária, foram amostradas 11 áreas nos estados do Paraná e Santa Catarina. Os resultados ampliaram significativamente o conhecimento da distribuição geográfica de oito espécies de anfíbios anuros: Ischnocnema henselii, Dendropsophus anceps, atualmente classificada como criticamente ameaçada no Estado do Paraná, D. nahdereri, Scinax granulatus, Trachycephalus dibernardoi, Pseudis cardosoi, Leptodactylus araucaria e L. nanus. Alguns destes registros representam correções em identificações anteriores: Ischnocnema henselii é uma espécie críptica e algumas populações até o momento eram confundidas no Paraná com I. guentheri; Trachycephalus dibernardoi era identificada como T. imitatrix e Leptodactylus nanus como L. marmoratus. A caracterização e descrição dos cantos destas espécies também são apresentadas.

The tadpole of Hypsiboas leptolineatus (Braun and Braun, 1977), a species in the Hypsiboas polytaenius clade (Anura; Hylidae)

The larval morphology of Hypsiboas leptolineatus was studied. The tadpole has an ovoid body in lateral view, wider than deep; snout rounded with dorsal reniform nostrils; spiracle sinistral with lateral wall attached to body; anal tube dextral; tail fins convex with acuminate tip; oral disc ventral; labial tooth row formula is 2(2)/3(1); moderately developed beaks with serrated jaw sheaths. These external oral features are compared with those of the known tadpoles in the Hypsiboas polytaenius clade. The oral cavity was studied using an electron microscope. Life history aspects are commented.

A new species of Pseudopaludicola Miranda-Ribeiro (Anura: Leptodactylidae: Leiuperinae) from eastern Brazil, with novel data on the advertisement call of Pseudopaludicola falcipes (Hensel)

The Neotropical genus Pseudopaludicola includes 21 species, which occur throughout South America. Recent studies suggested that the population of Andaraí, in the state of Bahia, is an undescribed species, related to P. pocoto. Herein we formally describe this new species from lowlands of eastern Brazil. Recognition of this new species is supported by adult morphology, advertisement call, karyotype, and molecular data. It is diagnosed mainly by its small size, terminal phalanges knobbed (lack any expansion of the digital tips), proportionally short hindlimbs, 11 pairs of chromosomes, and advertisement call composed of series of three-pulsed notes, emitted at a high rate. In addition, we report for the first time the presence of P. pocoto in the campo rupestre (rupestrian grasslands) of Chapada Diamantina, a population with a much darker dorsal coloration than the population from the type locality. We also redescribed the advertisement call of P. falcipes based on recordings from topotypic males.

Emergence of a bufonid herpesvirus in a population of the common toad Bufo bufo in Germany

Bufonid herpesvirus 1 (BfHV1) was initially described in 2014 from cases of mortalities and dermatitis in Swiss populations of the common toad Bufo bufo. We identified a closely related herpesvirus strain in a German common toad population affected by an ongoing epidemic of multifocal proliferative to ulcerative skin disease since 2018.

The identity of Hyla leucotaenia Burmeister, 1861 (Anura: Hylidae)

The German naturalist Carl Hermann Conrad Burmeister (1807-1892) had a prolific scientific career, spanning multiple taxa from diverse insect groups and trilobites to temnospondyls, birds, and extant and fossil mammals (see Berg, 1895). His contributions to anuran taxonomy are concentrated in two books, "Erläuterungen zur Fauna Brasiliensis…" (Burmeister, 1856) and "Reise durch die La Plata-Staaten…" (Burmeister, 1861). The latter is an account of his travels in Argentina and Uruguay from 1857-1860 and includes descriptions of three new species of frogs: Leiuperus nebulosus, Cystignathus mystacinus, and Hyla leucotaenia. While the first two names currently designate valid species, with the combinations Pleurodema nebulosum and Leptodactylus mystacinus respectively, the last name has had a more complex taxonomic history. It involves confusions involving a homonym, its consideration as a junior synonym of Hypsiboas pulchellus (Duméril & Bibron, 1841)-a widely distributed species in eastern Argentina, southeastern Brazil, and Uruguay (Frost, 2014)-and its actual identity corresponding to another widespread species in the same geographic area, with which it has never before been associated: Scinax squalirostris (A. Lutz, 1925). All these issues are discussed in this paper.