Diversification of the widespread neotropical frog Physalaemus cuvieri in response to Neogene-Quaternary geological events and climate dynamics.

Here we reconstructed the demographical history and the dispersal dynamics of Physalemus cuvieri through the Neogene-Quaternary periods by coupling DNA regions with different mutation rates, ecological niche modelling, reconstruction of spatio-temporal lineage dispersal and coalescent simulations. Still, to test alternative diversification scenarios we used approximate Bayesian computation. Molecular phylogenetic analysis recovered four deep and strongly supported clades, which we interpret as population lineages. The ancestral location reconstruction placed the root in southcentral Amazonia, and the dispersal events indicate that spatial displacement was widespread early in the diversification of this species. The demographical scenario of "Multiple Refugia" with recent lineage admixture was the most likely hypothesis to predict the observed genetic parameters of P. cuvieri. Our results revealed that Neogene orogenic events might have played a prominent role in the early diversification of P. cuvieri. The species shows deep divergences with strong regional population structure, despite its widespread distribution. Final uplift of the central Brazilian Plateau and formation of the river basins in Central South America played an important role in the origin, diversification and the maintenance of P. cuvieri lineages.

Ancestral reconstruction of reproductive traits shows no tendency toward terrestriality in leptodactyline frogs.

BACKGROUND: Traditionally, the evolution of terrestrial reproduction in anurans from ancestors that bred in water has been accepted in the literature. Still, the existence of intermediate stages of water dependency, such as species that lay eggs close to water (e.g., in burrows) instead of in bodies of water, supports the hypothesis of an ordered and gradual evolution in the direction of a more terrestrial form of reproduction. However, this conventional view has recently been challenged for some anurans groups. Leptodactylinae frogs are a remarkable example of anurans with an outstanding diversity in terms of reproductive features, with distinct water dependency among lineages. Here, we tested the hypothesis of a gradual and ordered tendency towards terrestriality in Leptodactylinae, including the existence of obligatory intermediate stages, such as semi-terrestrial reproductive strategies. We also addressed the association between reproductive modes and the morphological and ecological features. RESULTS: An ancestral reconstruction analysis indicated that even though shifts from aquatic to terrestrial breeding occurred throughout the history of Leptodactylus and Adenomera, shifts from terrestrial to aquatic reproduction happened at almost the same frequency. Our results also demonstrated that reproductive modes for semi-terrestrial tadpoles were not necessarily an intermediate form between aquatic and terrestrial breeds. Correlations among reproductive modes and other life-history traits suggested that tadpole environment, clutch size, nuptial spines, and egg pigmentation were co-evolving and driven by water dependency. CONCLUSIONS: Our results found no evidence of evolutionary tendencies toward terrestriality in Leptodactylinae. We found reversals from terrestrial to aquatic tadpole development and no evidence of obligatory intermediate stages, such as semi-terrestrial reproductive strategies. We also found correlations between reproductive modes and other life-history traits driven by water dependence. Aquatic reproductive modes are associated with higher clutch sizes, lentic waters, and the presence of nuptial spines and egg pigmentation.

Morfologia oral interna de larvas dos gêneros Eupemphix, Physalaemus e Leptodactylus (Amphibia: Anura) / Internal buccal morphology of the tadpoles of the genera Eupemphix, Physalaemus and Leptodactylus

A morfologia bucal interna das larvas de Eupemphix nattereri, Physalaemus albonotatus, P. centralis, P. cuvieri, Leptodactylus furnarius, L. fuscus, L. petersii e L. podicipinus são descritas e comparadas utilizando microscopia eletrônica de varredura. A larva de E. nattereri apresenta muitas diferenças quando comparada à larvas de anuros do gênero Physalaemus. As larvas de P. albonotatus, P. centralis e P. cuvieri apresentam semelhanças em sua morfologia bucal interna, tais como o número de papilas infralabiais e papilas laterais à crista mediana. P. centralis difere na quantidade de papilas pós-nasais e papilas da arena do teto bucal. Entre as larvas de Leptodactylus é possível perceber um padrão na distribuição e quantidade das estruturas bucais internas (papilas infralabiais e linguais, papilas das arenas do assoalho e teto bucal, crista mediana, papilas laterais da crista e papilas pós-nasais) nos grupos de espécies. Os caracteres da morfologia bucal larvária podem ser úteis quando utilizados conjuntamente com outros dados auxiliando na compreensão das relações sistemáticas da ordem Anura.

The internal buccal morphology of the tadpoles of Eupemphix nattereri, Physalaemus albonotatus, P. centralis, P. cuvieri, Leptodactylus furnarius, L. fuscus, L. petersii and L. podicipinus are described and compared using scanning electron microscopy. The tadpole of E. nattereri has major differences when compared to other tadpoles of the Physalaemus genus. The tadpoles of P. albonotatus, P. centralis and P. cuvieri present similarities in internal buccal morphology, such as the number of the infralabial and lateral ridge papillae, but P. centralis differ in the number of the post-narial and buccal roof arena papillae. Among the tadpoles of the Leptodactylus species is possible to observe patterns, in distribution and quantity of the internal buccal structures (infralabial and lingual papillae, buccal floor and roof arena papillae, median ridge, lateral ridge papillae and postnarial papillae) in the species groups. The characteristics of the internal buccal morphology may be useful when used together with other data helping in comprehension of the systematic of the order Anura.