The Neotropical poison frog genus Ranitomeya is revised, resulting in one new genus, one new species, five synonymies and one species classified as nomen dubium. We present an expanded molecular phylogeny that contains 235 terminals, 104 of which are new to this study. Notable additions to this phylogeny include seven of the 12 species in the minuta group, 15 Ranitomeya amazonica, 20 R. lamasi, two R. sirensis, 30 R. ventrimaculata and seven R. uakarii. Previous researchers have long recognized two distinct, reciprocally monophyletic species groups contained within Ranitomeya, sensu Grant et al. 2006: the ventrimaculata group, which is distributed throughout much of the Amazon, and the minuta group of the northern Andes and Central America. We restrict Ranitomeya to the former group and erect a new genus, Andinobates Twomey, Brown, Amézquita & Mejía-Vargas gen. nov., for members of the minuta group. Other major taxonomic results of the current revision include the following: (i) A new species, Ranitomeya toraro Brown, Caldwell, Twomey, Melo-Sampaio & Souza sp. nov., is described from western Brazil. This species has long been referred to as R. ventrimaculata but new morphological and phylogenetic data place it sister to R. defleri. (ii) Examination of the holotype of R. ventrimaculata revealed that this specimen is in fact a member of what is currently referred to as R. duellmani, therefore, Dendrobates duellmani Schulte 1999 is considered herein a junior synonym of D. ventrimaculatus Shreve 1935 (= R. ventrimaculata). (iii) For the frogs that were being called R. ventrimaculata prior to this revision, the oldest available and therefore applicable name is R. variabilis. Whereas previous definitions of R. variabilis were restricted to spotted highland frogs near Tarapoto, Peru, our data suggest that this color morph is conspecific with lowland striped counterparts. Therefore, the definition of R. variabilis is greatly expanded to include most frogs which were (prior to this revision) referred to as R. ventrimaculata. (iv) Phylogenetic and bioacoustic evidence support the retention of R. amazonica as a valid species related to R. variabilis as defined in this paper. Based on phylogenetic data, R. amazonica appears to be distributed throughout much of the lower Amazon, as far east as French Guiana and the Amazon Delta and as far west as Iquitos, Peru. (v) Behavioral and morphological data, as well as phylogenetic data which includes topotypic material of R. sirensis and numerous samples of R. lamasi, suggest that the names sirensis, lamasi and biolat are applicable to a single, widespread species that displays considerable morphological variation throughout its range. The oldest available name for this group is sirensis Aichinger; therefore, we expand the definition of R. sirensis. (vi) Ranitomeya ignea and R. intermedia, elevated to the species status in a previous revision, are placed as junior synonyms of R. reticulata and R. imitator, respectively. (vii) Ranitomeya rubrocephala is designated as nomen dubium. In addition to taxonomic changes, this revision includes the following: (i) Explicit definitions of species groups that are consistent with our proposed taxonomy. (ii) A comprehensive dichotomous key for identification of ‘small’ aposematic poison frogs of South and Central America. (iii) Detailed distribution maps of all Ranitomeya species, including unpublished localities for most species. In some cases, these records result in substantial range extensions (e.g., R. uakarii, R. fantastica). (iv) Tadpole descriptions for R. amazonica, R. flavovittata, R. imitator, R. toraro sp. nov., R. uakarii and R. variabilis; plus a summary of tadpole morphological data for Andinobates and Ranitomeya species. (v) A summary of call data on most members of Andinobates and Ranitomeya, including call data of several species that have not been published before. (vi) A discussion on the continued impacts of the pet trade on poison frogs (vii) A discussion on several cases of potential Müllerian mimicry within the genus Ranitomeya. We also give opinions regarding the current debate on recent taxonomic changes and the use of the name Ranitomeya.

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.

Factors contributing to the evolution of reproductive strategies have been of great interest to evolutionary biologists. In tropical amphibians predation and competition have been suggested to play a major role. Poison frogs of the family Dendrobatidae display a trend towards the use of very small pools and increased parental care, particularly in the genus Dendrobates. Some species with female parental care, asymmetrical biparental care and biparental care, have evolved novel behaviors in association with the use very small phytotelmata. It has been hypothesized that selection pressure imposed by predation and competition favored the use of small phytotelmata, and this, in turn, produced selection for trophic egg provisioning to ameliorate the lack of available nutrients. To elucidate the ecological factors associated with the transition from uniparental male care to biparental care and associated changes in social behaviors, we evaluated key behavioral and ecological differences between Dendrobates imitator and D. variabilis. Dendrobates imitator used significantly smaller phytotelmata in different plant species than D. variabilis for tadpole and embryo deposition. The parental strategy of D. variabilis was limited to male parental care, whereas D. imitator exhibited biparental care. Males and females of D. variabilis were observed to have a promiscuous mating system with little mate fidelity. This contrasted with D. imitator, where paired males and females were observed interacting daily and were never observed courting additional mates. Our results are consistent with the hypothesis that a key ecological difference between these species, involving the size of pools typically used for reproduction, is strongly associated with the evolution of biparental care and monogamy in D. imitator.

In a mimetic radiation-when a single species evolves to resemble different model speciesmimicry can drive within-species morphological diversification, and, potentially, speciation. While mimetic radiations have occurred in a variety of taxa, their role in speciation remains poorly understood. We study the Peruvian poison frog Ranitomeya imitator, a species that has undergone a mimetic radiation into four distinct morphs. Using a combination of colour-pattern analysis, landscape genetics and mate-choice experiments, we show that a mimetic shift in R. imitator is associated with a narrow phenotypic transition zone, neutral genetic divergence and assortative mating, suggesting that divergent selection to resemble different model species has led to a breakdown in gene flow between these two populations. These results extend the effects of mimicry on speciation into a vertebrate system and characterize an early stage of speciation where reproductive isolation between mimetic morphs is incomplete but evident.

Peru is well known for amphibian diversity and endemism, yet there have been relatively few field studies of glassfrog (Centrolenidae) diversity in this country. Research in Colombia and Ecuador indicates that centrolenid diversity is higher in the northern Andes. However, part of this trend appears to be due to sampling effort. We conducted fieldwork throughout northern Peru, and based on phylogenetic analysis of DNA sequences, combined with bioacoustic and morphological analyses of new and available material we now recognize 33 species from the country (versus 30 species prior to this work). Field surveys led to the discovery of four remarkable species: Centrolene charapita new species is a large, ornamented glassfrog that appears to be sister to Ce. geckoideum; Chimerella corleone new species represents the second-known member of the genus Chimerella; Cochranella guayasamini new species is the second-known member of the genus with humeral spines; and Hyalinobatrachium anachoretus new species occurs in the cloud forest of the east-Andean versant in Peru. In addition to the new species described here, we provide new country records, new localities including range extensions of up to 875 km, information on diagnostic characters and phylogenetic relationships, call and larval descriptions, and observations on natural history for several Peruvian centrolenids. Our results also revealed several taxonomic problems concerning species of the genus Rulyrana, and we conclude that R. croceopodes and R. tangarana are junior synonyms of R. saxiscandens. By implication of our phylogenetic analyses, we recognize the following new combinations: Espadarana audax new combination, Espadarana durrelorum new combination, and Espadarana fernandoi new combination.