ABSTRACT. This study concerns the patterns of parasitism by the larvae of Eutrombicula alfreddugesi (Oudemans, 1910) on three species of Tropidurus Wied, 1820 from Cerrado habitats of Central Brazil: T. oreadicus Rodrigues, 1987 (n = 97), T. itambere (n = 85) and T. torquatus (Wied, 1820) (two samples n = 75, n = 23). The highest prevalence value was observed in T. itambere (88.2%), followed by T. oreadicus (87.6%), and T. torquatus (17.3% and 65.2%). The most important sites of infestation were the mite pockets and skin folds, especially on the neck and inguinal region. Tropidurus itambere Rodrigues, 1987 was the most heavily parasitized species (mean intensity of infestation: 36.67 ± 41.09), followed by T. oreadicus (15.38 ± 21.08), and T. torquatus from Unaí, Minas Gerais (12.13 ± 21.09). The lowest intensity of infestation was found in T. torquatus from urban and periurban areas of Brasília, Distrito Federal (1.97 ± 5.43). The analysis did not indicate differences in intensity of infestation between sexes for any of the species. Differences in the patterns of parasitism among the three lizard species may be related to the morphological and numerical variation of the skin folds (especially mite pockets), to the degree of conservation of the host's habitats, and to selective processes related to reduction of damage to the host's bodies, to the evolution of mechanisms of decreasing illness transmission by parasites, or even to some behavioral traits of the lizards.

Based on comprehensive distributional records of the 23 species currently assigned to the lizard genus Tropidurus, we investigated patterns of endemism and area relationships in South America. Two biogeographic methods were applied, Parsimony Analysis of Endemicity (PAE) and Brooks Parsimony Analysis (BPA). Two areas of endemism were detected by PAE: the first within the domains of the semiarid Brazilian Caatinga, which includes seven endemic species, and the second in the region of the Serranía de Huanchaca, eastern Bolivia, in which three endemic species are present. The area cladograms recovered a close relationship between the Atlantic Forest and areas of the South American open corridor. The results revealed a close relationship among the provinces Caatinga (Cerrado, Parana Forest (Pantanal+Chaco)). The uplift of the Brazilian Central Plateau in the Late Pliocene-Early Pleistocene (4-2 Myr BP) has been interpreted as a major event responsible for isolation and differentiation of biotas along these areas. However, we emphasize that without the establishment of a temporal framework concerning the diversification history of Tropidurus it is premature to correlate cladogenetic events with specific time periods or putative vicariant scenarios. The limiting factors hampering the understanding of the biogeographic history of this genus include (1) the absence of temporal references in relation to the diversification of distinct clades within Tropidurus; (2) the lack of an appropriate taxonomic resolution of the species complexes currently represented by widely distributed forms; and (3) the need for a comprehensive phylogenetic hypothesis. We suggest that these three important aspects should be prioritized in future investigations.

Darwin and Wallace, in the mid-nineteenth century, were the first to document examples of natural selection acting on island dwellers. A century later a pattern of morphological differences among organisms on islands was coined the 'island rule', which states that on islands species with small individuals tend toward gigantism and large individuals tend toward dwarfism. Selective pressures such as limited resources and increased intraspecific competition modulate the size of organisms in these environments. Of the several works that have tested vertebrates for adherence to the island rule only two have addressed amphibians. This work is the third record of body size variation of island amphibian populations, and the first for the Southern Hemisphere. The islands investigated were once continuous with mainland, and now are isolated as a result of sea level fluctuations that took place in the Pleistocene and Holocene. This study compared morphometric variation in populations of Rhinella ornata (Bufonidae) occurring on three islands of the Costa Verde to populations on five continental areas in Rio de Janeiro, Brazil. We measured 18 morphometric variables of 177 individuals. There was a shift toward smaller body size (dwarfism) in two of the three island populations studied. We attribute this general pattern to geographic factors, verifying the expression of the island rule in tropical frogs populations (insular dwarfism) operating inversely in relation to those of temperate environments (island gigantism).Abstract in Portuguese is available in the online version of this article.

Abstract:We report the results of a seven-year survey of the anurans of Marambaia, in the State of Rio de Janeiro, southeastern Brazil, where 24 species were recorded. The species represented nine families: Hylidae (10 species), Bufonidae (3), Leptodactylidae (3), Hylodidae (2), Microhylidae (2), Craugastoridae (1), Centrolenidae (1), Cycloramphidae (1), and Leiuperidae (1). We also present notes on the natural history and habitat usage by the anurans.

Among vertebrates, anuran amphibians represent the highest number of species associated with bromeliads and possess a range of ecological, behavioral, and morphological specializations to life in these plants. Despite the importance of bromeliads as biodiversity amplifiers, and their diversity in some habitats, studies of the relationship between anurans and these plants are scarce in Brazil. Here, we investigated the way anurans select and use bromeliads in a threatened coastal habitat. We analyzed data from 23 standardized samples of the anurans associated with the bromeliad Neoregelia cruenta in the Restinga de Maricá, State of Rio de Janeiro, Southeastern Brazil. We found nine anuran species using these bromeliads, representing the highest richness reported for a Brazilian restinga. We identified a general pattern of bromeliad usage, where plants located at the edges of scrub patches (exposed to the sun) were more frequently occupied by anurans than those located more to the center (in the shade). There is strong evidence of an active selective process based on the quality of the water stored in the rosette, which differs between plants depending on their position in the scrub patch. Although the number of individuals varied during the period of study, the frequency of bromeliads used was constant, indicating that plant occupation follows a regular pattern throughout the year. Furthermore, the high frequency of bromeliads used by anurans during the whole year highlights the importance of considering these plants in developing conservation programs concerning the protection of anurans.Abstract in Portuguese is available at http://www.blackwell-synergy.com/loi/btp.

We compared the effects of habitat disturbance on the feeding ecology of two local populations of Tropidurus torquatus (Wied, 1820) in restinga habitats on Ilha da Marambaia, Southeastern Brazil. Both populations presented a relatively diverse diet and differ in the number (D Max = 0.22, DF = 2, p = 0.00) and volume of prey consumed (D Max = 0.82, DF = 2, p = 0.00). Ants were the most frequent and numerous preys in both areas, and plant matter and coleopterans were the most important alimentary items in volume. The population from the disturbed area presented a larger niche breadth for number of prey items consumed (Bi num = 3.06) and volume (Bi vol = 2.98), when compared to the other population (Bj num = 2.44, Bj vol = 1.52). Niche overlap was higher for number of items consumed between the populations (Oij num = 0.82) but lower for volume (Oij vol = 0.05). Our data suggest dietary differences between the two lizard populations, and these differences may be associated with environmental modifications. Our main hypothesis to explain the dietary differences is based in the Optimal Foraging Theory. However, the alimentary behavior, and consequently the diet of these lizards, seems to be constrained phylogenetically, with a pattern that may have evolved in the ancestor of all iguanids.

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We describe Scinax pombali sp. n. a new species of treefrog of the Scinax catharinae group from Serra da Canastra, municipality of Capitólio (20°36'03''S, 46°17'34.9''W, 987 m a.s.l.), located in the Cerrado domains of the State of Minas Gerais, Southeastern Brazil. The new species is characterized by its small size, blotches and color pattern on dorsal surface and hidden regions of flanks and thighs, canthus rostralis lightly concave and well marked, absent nuptial pad, and lack of externally differentiated inguinal gland. Additionally, we describe the tadpole of this new species, which is characterized by the large-sized oral disc and presence of a large number of marginal papillae (two to three rows on its dorsal portion and some rows in unorganized arrangement on its lateroventral portion).