We determined the blood biochemistry parameters for the breeding population of green turtles (Chelonia mydas) in the Aves Island Wildlife Refuge (Venezuela), the second largest breeding colony of relevance in the Caribbean. We collected 59 blood samples (48 nesting females and 11 adult males) by puncturing the dorsal cervical sinus. Sexual maturity was estimated by measuring curved carapace length, curved carapace width, and tail length (only in males). We used colorimetric techniques for biochemical analysis. Mineral concentrations in the samples were determined by atomic absorption (Ca, Mg, Zn, Cu, and Mg) and emission (Na and K) spectrometry. This study provides valuable biochemistry reference values for breeding populations of green turtles from Venezuela and the Caribbean. The population is considered healthy, with parameter values coinciding with previously reported reference ranges of species in the Caribbean and Atlantic populations. We conclude that, for the population in the Aves Island Wildlife Refuge, variability in the values obtained for total protein, albumin, blood urea nitrogen, alanine aminotransferase, glucose, triglycerides, HDL-cholesterol, calcium, phosphorus, magnesium, and copper was directly related to factors such as sex and animal size.

The viability and interpretation of techniques for the evaluation of immunocompetence of animals in their natural environment has been largely debated. One of these methods is based on testing the antimicrobial capacity of the blood and/or plasma in vitro, which could rapidly and effectively assess the immunological conditions of natural populations. We tested the applicability of the antimicrobial capacity of plasma (ACP) assay in anuran amphibians from the Atlantic Forest. The assay was performed by measuring both the turbidity (in a spectrophotometer) and the colony forming units (CFU) of the remaining bacteria (Escherichia coli) following exposure to amphibian plasma. Although both assays were correlated, the ACP assay by spectrophotometry showed 10 times lower intra-assay variation. We also found interspecific variation in ACP, as well as the maintenance of ACP values in males from the same population, collected in different breeding seasons. Thus, the estimation of ACP by spectrophotometry provides a convenient and accurate method for evaluating innate immunocompetence in comparative and ecophysiological studies of anuran amphibians.

We describe the diet of adult and juvenile Engystomops pustulatus from three populations in the Ecuadorian Chocó. Analysis of the items recovered from the gastrointestinal tracts of 95 individuals showed that E. pustulatus has a diverse diet. We identified 52 prey types among 1211 items. The numeric niche breadth, as measured by the Simpson's Index, was 5.37 while the volumetric niche breadth was 5.48. Among juveniles at Cerro Blanco we found a high proportion of small prey items, including termites and ants. Larger items, including snails, coleopterans, and isopods, were most frequent in adults at Patricia Pilar and La Maná. We hypothesize that dietary niche breadth is correlated with the presence of teeth in Engystomops. Engystomops pustulatus has teeth and has a more generalist diet than the termite and ant specialist species E. pustulosus, E. petersi, and E. freihergi, which lack teeth.

Diet, reproductive patterns, and sexual dimorphism are described of Chironius fuscus from Brazilian Amazonia based on the analysis of museum specimens (n = 120 for diet and reproduction; n = 333 for dimorphism). The diet was composed primarily of anurans. No relationship was found between snake body size and prey type, and the species showed no preference for direction of prey ingestion, probably due to the consumption of a prey type that does not present injury risk to the snake. No differences in diet composition were found between males and females or adults and juveniles. Many breeding females had prey in their digestive tracts. Males reach sexual maturity atsmaller size than females and no evidence of seasonal breeding was found. We observed 1–6 secondary follicles ( = 3.3) and 3-6 eggs ( = 4.3). The species is sexually dimorphic, with males being significantly longer and having a higher number of ventral scales, whereas females have significantly longer tails, larger eyes, and a higher number of subcaudal scales. This species differs from most other colubrids, especially arboreal species, which tend not to show sexual dimorphism. No significant difference between sexes was found in head length or width.

In turtles, the selection of the nesting area is critical for the survival of the embryos. This study investigated the environmental characteristics of nesting areas selected by Podocnemis unifilis and the spatial distribution of the nests, as well as the influence of these factors on hatching success in a floodplain area of the lower Amazon River in Brazil. The influences of the nesting date, depth of the nest, height above the river level, distance to the river and to vegetation, grain size of the substrate, and beach slope on hatching success were evaluated. Nests and randomly selected points were compared to determine if the nest sites differed from other locations on the beach, and if the females exercised control over this choice. We observed that females selected the higher sites, far from the river and next to vegetation for nesting. The nests were distributed along the beach and in the steeper “cut bank” along the outer side of bends. The main causes for loss of nests were flooding, predation and human collecting. The height of the nest above the river affected the probability of nest flooding when the river began to rise. Predation and collecting affected mainly the first nests of the season, and the collected nests also were closer to the river and vegetation, and sited higher on the beach. Keeping the nests in their natural environment is the most appropriate conservation strategy, which can be combined with protection by the local residents.

Patterns of geographical variation in morphology provide an empirical framework for testing the effects of ecological and historical factors on species differentiation. Environmental gradients play an important role in intraspecific differentiation through morphological adaptation in locations with distinct selective pressures. Vanzosaura rubricauda is a small microteiid lizard that is widespread in the great diagonal of dry biomes of South America, occurring in Cerrado, Caatinga, and Chaco open habitats with contrasting environmental conditions. Using multivariate morphometrics and spatial analysis, we show that V. rubricauda presents a structured pattern of geographic variation, with populations of the eastern Cerrado being distinct in morphometry. Geographical variation was observed in size and shape, with a general trend of contrast between trunk length and forelimb length among populations. Ecogeographical models that best explained geographic patterns of variation were aridity and precipitation.

A new salamander of the genus Pseudoeurycea is described from the Mexican state of Guerrero, bringing the number of species in this genus known from this state to nine. It occurs on the Pacific slopes of the Sierra Madre del Sur in the western portion of the state. This new salamander is diagnosed from Guerrero congeners by its morphology and color pattern.

We describe and illustrate the external morphology, oral disc, chondrocranium, and internal oral anatomy of Leptodactylus caatingae larvae. We analyze the internal oral anatomy using scanning electron microscopy of a larva in Gosner stage 38 and chondrocranial anatomy is reported for Gosner stage 34. The tadpole at Gosner stage 38 has a globular body shape with low tail fins and a ventral oral disc bordered by two rows of marginal papillae on most of the disc, except for the anterior labium and a medial portion of the posterior labium where papillae are simple; a wide rostral gap is present; labial tooth row formula: 2(2)/3(1). Observations on the natural history of adults and tadpoles are also reported. The external morphology of these tadpoles is compared with available descriptions for larvae of L. latinasus and other congeners that occur in sympatry with L. caatingae. Internal oral morphology and chondrocranial anatomy are discussed in relation to available data for other species in the L. fuscus species group.