A new species of bufonid toad of the genus Melanophryniscus is described from a mountaintop that is part of the Serra do Mar in the northeastern State of Paraná, Brazil. Melanophryniscus alipioi sp. nov. is distinguished from other known species by its uniformly dark brown dorsal color and a unique breeding site. The new species reproduces in bromeliads, a reproductive mode previously unknown for this genus. This species might be susceptible to current habitat lost.

Little is known about the reproductive biology of species of the genus Melanophryniscus. This study provides the first description of amplexus behaviour, egg-laying sites, clutch characteristics and larval development of Melanophryniscus sp., a species of uncertain taxonomic status that is found in the southernmost range of the genus (Sierra de la Ventana, Argentina), and their relationship with habitat features and selection pressures is discussed. Results are compared with the reproductive biology of other species in the genus.

Species of the genus Leptodactylus formerly referred to the genus Adenomera and now included in the Leptodactylus marmoratus species group are known to deposit eggs in foam nests in underground chambers. In this paper we detail the reproductive biology of a species of Leptodactylus (formerly Adenomera) from an open area in the Amazonian biome. We observed the breeding site, courtship behaviour, structure of underground chambers, and described the advertisement call and tadpole morphology. Leptodactylus aff hylaedactylus was found breeding in grasses (Brachiaria) and gardens in non-flooded areas, using underground chambers to lay its eggs. Underground chambers (n = 5) were simple constructions: a spherical chamber with no tunnel. We found tadpoles at different stages of development and obtained information about foam nest characteristics, time of hatching, size at metamorphosis, and fecundity. We tested in the laboratory the ability of tadpoles to generate foam independently of parents. The ability of the tadpoles to generate foam independently of the parents could represent a synapomorphy of the species of the Leptodactylus fuscus, pentadactylus and marmoratus species groups. The advertisement call of the species studied herein differs from other Amazonian Leptodactylus species and could represent a new species of this genus.

A new species of the genus Dendrophryniscus is described from Reserva Biológica da Serra Geral, Municipality of Maquiné, and Parque Nacional dos Aparados da Serra, Municipality of Cambará do Sul, State of Rio Grande do Sul, Brazil. Dendrophryniscus krausae sp. nov. is associated to the D. brevipollicatus group and is characterized by its medium size for the genus (snout-vent length 19.2–21.2 mm in males, 20.4–24.0 mm in females); body robust, slightly enlarged posteriorly; finger I short, robust, and in males with moderate nuptial pad of minuscule dark brown horny asperities; presence of few small granules, dispersed on upper eyelid surfaces; and external margin of upper eyelid weakly prominent.

A new species of Hypsiboas is described from the Atlantic Forest in Santa Catarina State, southern Brazil. The new species is morphologically similar to Hypsiboas marginatus, from which it differs by its smaller size, flanks with white blotches, a white stripe on the upper lip exceeding posteriorly to the tympanum, a white dorsolateral stripe reaching the inguinal region, tadpole with body black, tail whitish-yellow translucent, and labial tooth row formula 2(2)/5(1). The new species inhabits Atlantic Forest environments within mountain ranges from eastern Santa Catarina State, denominate Serras do Leste Catarinense, while H. marginatus occurs in the Serra Geral mountain range, in southern Santa Catarina and northeast Rio Grande do Sul State, and thus have allopatric distributions. The new species is included in the Hypsiboas pulchellus species group, and its relationship with other members of the group is discussed herein. We also discuss the conservation status of the new species in relation to the IUCN Red List Categories and Criteria of threatened species.

Melanophryniscus pachyrhynus (Miranda-Ribeiro, 1920) was known from only two syntypes collected in southern Brazil about 100 years ago. Recently, we discovered many specimens from several localities in Brazil, and specimens were also reported for Uruguay. The Brazilian specimens were found during field trips or were stored in collections under incorrect names. Based on analysis of live specimens and freshly collected material we report that M. pachyrhynus is a relatively common species in southern Brazil, extend its geographic distribution, and add information to the species redescription.

We here report on the venom composition of Bothrops insularis, an endemic snake from the island of Queimada Grande (São Paulo, Brazil) that shows ontogenetic change on diet. Electrophoretic profiles showed similar patterns among samples at distinct ages. Densitometric analysis showed an increase of expression of proteic band at 24 kDa of molecular mass range. Venom toxicity was higher for bees (just-emerged Apis mellifera) and chicks (one day age Bovans white chicks) than for swiss mice, although a direct relation with ontogeny was not established. Venom selectivity towards local preys was demonstrated by the strong toxicity upon arthropods and chicks in comparison to mammals. Results suggest that the venom of Bothrops insularis has peculiarities on its composition that supports a specialized diet on its insular habitat and, although a conspicuous ontogenetic diet change occurs in the species, venom toxicity towards local preys is a characteristic present during the whole life cycle. Our results also provide strong evidence of the presence of taxon-specific toxicity in the venom of B. insularis, and a tendency of the adult venom to be more toxic than the one from young individuals.

The calling activity and agonistic behavior of Pseudis minuta Günther, 1858 were described based on observations made in the Reserva Biológica do Lami, Porto Alegre municipality, Brazil. Field work included bimonthly surveys in one semipermanent pond, each lasting approximately two days and two nights, from August 2004 to July 2005. Males produced three distinct calls: the advertisement call and two aggressive calls. The dominant frequency of the advertisement call was not correlated with the mass or the snout-vent length of the recorded males. We observed two agonistic interactions between males: one involved acoustic interaction, and the other, acoustic and physical interactions. Calling activity was primarily nocturnal, and occasionally diurnal, with peak at about 2300 h. The number of calling males varied significantly through the year with a peak in September.

Previous studies indicate that (1) defensive displays are associated with habitat use in snakes, (2) visual defenses correlate better with habitat than with phylogeny, and (3) arboreal snakes are more exposed to predators than terrestrial species. We hypothesize that similar patterns exist for diurnal versus nocturnal snakes, and test these hypotheses against the occurrence of 13 defense types directed to visually oriented predators in 92 colubrids from two Neotropical assemblages, one from central Amazonia (26 genera, 41 species) and another from the Atlantic Forest (23 genera, 62 species). Arboreal species and genera displayed more visual defensive tactics than terrestrial ones. Frontal display, gaping, gular inflation, head elevation, neck S-coil, and, apparently, head triangulation, tended to be more frequent in arboreal species, whereas dorsoventral body depression and, apparently, polymorphism, were more frequent in terrestrial ones. Peculiarities of the arboreal microhabitat, such as the prevalence of a green background, a likely higher exposition to predators, and the variety of directions from which a predator would approach may have led to the evolution of peculiar visual defensive tactics in arboreal species. With regard to time of activity, the number of visual defensive tactics was not different between diurnal and nocturnal species or genera. However, frontal display, gaping, gular inflation, and crypsis were prevalent in diurnal snakes, whereas mimicry and, apparently, head triangulation were more frequent in nocturnal forms. Furthermore, green was significantly more frequent in diurnal species, whereas contrasting color patterns were more frequent in nocturnal species. A cluster analysis based on the occurrence of visual defenses resulted mostly in heterogeneous groups of genera regarding phylogenetic position (clade), preferred microhabitat and time of activity. In general, our analyses indicate that the way Neotropical snakes defend themselves from predators results from a complex interaction between ecological factors and phylogenetic constraints.

In this study we sampled diurnal and nocturnal anuran assemblages in 10,000 ha of tropical forest. We provide data on composition and variation in the occurrence and abundance of these species during two rainy seasons. Our study took place at Reserva Florestal Adolpho Ducke, Manaus, Amazonas state, Brazil. We analysed the anuran assemblage for three diurnal samples and five nocturnal samples from November/2002 to May/2004. Data were collected in 72 plots systematically distributed over a 64 km² grid. Diurnal anuran assemblage surveys were conducted by visual encounter. We sampled the nocturnal anuran assemblage using standardized methods – simultaneous visual encounter surveys and auditory sampling. We detected 30 species of anurans, belonging to seven families using all methods and periods. A total of 6,030 individuals belonging to eight species and four families were recorded in diurnal samples and 25 species (16,050 individuals), belonging to six families were recorded in nocturnal samples. The number of nocturnal species varied from 18 in the beginning of the second rainy season to 22 in the middle of the rainy season. Fourteen species were found in the five sampling periods. The species with high abundance that were widely distributed in the study area were those with reproductive specializations such as direct development, development in terrestrial nests, or development in bromeliads with parental care. This study showed the viability of the system of surveys and the methods used for sampling anuran assemblages in a tropical forest. They were also adequate for estimating the richness and abundance of species. However, systematically distributed plots, such as those used in this study, mostly reveal terrestrially breeding frogs. The aquatic-breeding frogs were found mainly in riparian zones and were rare in zones distant from water bodies. There were a low number of plots around water bodies (25%) which, consequently, reduced the record of aquatic-breeding individuals.

Among mortality factors for juvenile lizards one of the most important is predation, either by individuals of different sympatric species or by individuals of the same species (cannibalism). We analyzed the available data in the literature regarding Brazilian lizards in order to evaluate the role of lizards as source of mortality for juvenile sympatric lizards, with emphasis on cannibalism. We found a total of eight species of juvenile lizards reported as prey of other sympatric lizard species, and six species of lizards that preyed on juvenile ones. Of the 13 records of predation on juvenile lizards, 46.1% were made by tropidurid lizards, 30.8% by teiids, and 23.1% by skinks. We found a total of 13 cases of cannibalism reported for nine species of lizards, with the frequency of occurrence varying from 0.7 to 3.8% in the sample of the lizards analyzed. Most cannibalistic lizards were males, which are the sex with the largest body size in most species, but in species of Mabuya, in which males are smaller than females, only females were reported as cannibalistic. The opportunistic feeding habits of the lizards, as well as the relatively high densities of most species may facilitate the encounters between predators and prey, including cannibalistic events.