A reproductive strategy includes physiological, morphological, behavioral traits dependent on exogenous and endogenous regulators, including size/age at maturity, temporal variation in gametogenic cycles, and size-fecundity relationships. Sexual differences in reproductive investment, territoriality and resource use may result in sexual dimorphism on body size and other morphological traits. These life-history components are key for understanding the selective forces underlying male and female reproductive strategies in a population. We investigated the reproductive biology of the stream-breeding frog Crossodactylus schmidti through the histological analysis of testes, ovaries, and bone samples. Mature males and females and free-swimming tadpoles occurred in all months, though the monthly proportion of mature females was variable. Free spermatozoa, sperm bundles, and germ cell cysts in several stages occurred in testes of all except two males, whilst ovaries of most females presented all follicle stages, indicating continuous gametogenesis in both sexes. There was no significant seasonal variation in snout–vent length (SVL), body mass (BM) or in the gonadosomatic index for neither sex, further indicating a continuous pattern of reproduction. Minimum SVL and age at sexual maturity was 22.14 mm and 2 a, respectively, in males, and 21.78 mm and 3 a, respectively, in females; both sexes reached up to six years of longevity. Gonad mass increased with BM in both sexes, though this effect was much stronger in females. After controlling for age, females were significantly larger than males in SVL, BM, and MW (mouth width): the larger female body size suggests selection for increased fecundity, whereas the larger MW possibly favors the consumption of large, energetically important prey for sustaining the continuous egg production. Finally, there was a positive correlation between female SVL and number of thumb spines, but the number of thumb spines did not differ between the sexes; we briefly discuss a possible role of thumb spines in the courtship of C. schmidti based on field observations.

Anuran malformations are rarely reported to occur with high frequencies in natural populations. However, there is consensus that they can be caused by several factors. Herein, we report malformations in Rhinella ornata toads from land-bridge islands and compare their frequency with those of mainland populations from Rio de Janeiro. All islands showed levels of malformation significantly higher than the threshold of 5%, and one of the islands, Ilha Grande—which is the largest, farthest from the coast, and has been isolated for the longest time—had the highest frequency of morphological defects. Although it is possible that factors such as chemical contamination and parasite infection cause these defects, we also propose populational bottlenecks as contributing to the high frequency of malformations. Further studies are needed to understand the causes and consequences of malformations in these insular populations.

We describe the first undisputable fossil of Rhinoclemmys (Cryptodira, Geoemydidae) east of the Andes, represented by an isolated nuchal bone found in one of the most important paleontological sites with association of fauna and humans (Muaco site, western Venezuela) from the Late Pleistocene of the southern Caribbean. The nuchal is complete and slightly wider (4.8 cm) than long (4.2 cm), preserving well-defined sulci of the cervical, vertebral 1, marginal 1, and pleural 1. Comparisons with extant and fossil specimens of Rhinoclemmys allow us to attribute this nuchal to Rhinoclemmys, albeit as an indeterminate species. The occurrence of Rhinoclemmys in the southern Paraguaná Peninsula indicates that during the Late Pleistocene this region had environmental conditions that allowed the survival of these freshwater-terrestrially adapted reptiles, particularly of “paleo-springs” inside a semi-arid region.

Proceratophrys minuta is known from two localities in the state of Bahia, northeastern Brazil. Information on the tadpoles and natural history of adults and larvae is available in the literature, but its advertisement call remains undescribed. Herein, we describe the advertisement call of P. minuta on the basis of four males recorded at the type locality in the municipality of Miguel Calmon, state of Bahia, Brazil. The advertisement call consists of one note with 30–52 pulses and duration of 0.4–0.72 s. The pulses usually present shorter attack than decay, with amplitude varying throughout the call. The dominant frequency over the course of the call is 1.98–2.07 kHz. The advertisement call of P. minuta is compared with available call descriptions of 25 species of Proceratophrys. It is promptly diagnosed from the calls of almost all congeners by presenting the highest dominant frequency, except for P. avelinoi, from which P. minuta can be distinguished on the basis of qualitative parameters (pulse amplitude modulation) and pulse duration. All Proceratophrys species share the following structural features of the advertisement call: notes composed of regularly repeated pulses with amplitude modulation throughout the calls and low dominant frequencies varying from 0.2–2.3 kHz. The advertisement call differs among species of Proceratophrys in the general shape of the call envelope due to distinct patterns of amplitude modulation, being either gradually modulated or abruptly modulated. We tested and obtained negative correlation between species dominant frequencies and body size in Proceratophrys, drawing attention to the importance of body size in the evolution of vocalization. Furthermore, we observed high acoustic similarities among phylogenetically distant species, indicating that quantitative parameters of the call are not likely to predict phylogenetic relatedness. Nevertheless, qualitative characters might recover the phylogenetic relationship among Proceratophrys species, and, further, they might elucidate how the the advertisement call encodes crucial information for mate recognition and discrimination.

Knowledge of reproductive biology is essential to understand the intrinsic traits of any species and to elaborate effective conservation strategies, particularly for threatened species. Despite recent advances, knowledge on the reproductive biology of snakes remains deficient for most species, especially for tropical fossorial taxa. Apostolepis gaboi is a psammophilous, fossorial, and threatened snake endemic of the Quaternary Sand Dunes of the São Francisco River, Caatinga domain. Here, we present information on its reproductive biology based on macroscopic and microscopic data obtained from the examination of all specimens preserved in Brazilian museums. Specifically, we addressed sexual maturity, sexual dimorphism, clutch size, timing of gametogenesis, activity of the sexual segment of the kidney (SSK), and female sperm storage. Apostolepis gaboi is one of the smallest species of the genus. Females attain sexual maturity at larger body sizes and grow larger than males. However, adult females have relatively shorter tails than males. We found no sexual dimorphism in body circumference and head size. Clutch size is small and averages 4.5 eggs. All males from the wet season showed testes in spermiogenesis, ductus deferentia packed of sperm, and SSK hypertrophied and secretory. Secondary vitellogenesis also occurs in the wet season. Moreover, females in early vitellogenesis from the wet season showed sperm stored in the posterior infundibulum. Mating occurs in the second half of the wet season, as suggested by the finding of aggregations of sperm in the uterine lumen of a female in early secondary vitellogenesis. Mating is associated with gonadal activity in males. Sperm storage confers flexibility for females to ovulate at the most suitable time in an unpredictable habitat such as the Caatinga. Apostolepis gaboi exhibits similarities (association between mating and spermiogenesis, small clutch) and differences (absence of sexual dimorphism in head size and stoutness) compared with another Elapomorphini species. Lastly, we argue that some of the intrinsic traits of A. gaboi (small clutch and small body size) may increase its vulnerability to extinction, raising additional concerns to its conservation.

We examined the effects of landscape changes in an environmental gradient of forest, a Vernicia fordii plantation, and crops on the distribution patterns of amphibians in San Rafael National Park. We conducted eight periods of fieldwork between June 2012–April 2013 and used pit fall traps with drift fences to capture amphibians. We recorded eight species of the families Bufonidae, Leptodactylidae, and Odontophrynidae. The environmental variables correlated with the abundance of amphibians were relative humidity, litter depth, herbaceous cover, and air temperature, and significant differences were found in species composition. Generalist species like Leptodactylus mystacinus and Physalaemus cuvieri were found in the most altered areas such as crops and the plantation. Rhinella ornata and Proceratophrys avelinoi were primarily restricted to primary forests, and their abundance was sensitive to forest lost and degradation. Our results support the idea that modified habitats influence distribution patterns of amphibians, and the protection of the remnants of pristine Atlantic Forest is a critical step in the conservation of anuran biodiversity in Paraguay.

The reproductive activity of most of tropical Andean snakes is unknown, especially for fossorial species. An undescribed species of Atractus from Cordillera Oriental of Colombia occupies a habitat that undergoes two rainy seasons and two dry seasons. This strongly seasonal climate suggests that the reproductive phenology of the species might be seasonal or continuous with reproductive peaks related to rainfall. To test this hypothesis, we studied the annual reproductive activity of this population and other aspects of its reproductive biology. We determined the reproductive stages in males by studying morphometry and histology of the testes, sexual segment of the kidney (SSK), and excurrent ducts. In females, reproductive stages were based on the macroscopic and morphometric analyses of the ovaries and histology of the oviducts. Adult males had spermatozoa in testes and ducts and hypertrophied SSK throughout the year. Similarly, reproductive (vitellogenic) females were found during most of the year; however, a high percentage of adult non-reproductive females (44%) was also found throughout the year. Therefore, females are asynchronous in their reproductive stage. Similarly, juveniles of different sizes were found year-round and no particular time of neonatal recruitment was detected. All adult females had abundant sperm within crypts, the lumen of the vagina, and the utero-vaginal junction, suggesting extended or permanent female receptivity. In contrast, although all females had seminal receptacles in the posterior infundibulum, only late vitellogenic females had sperm within these receptacles, suggesting preovulation migration of sperm from vaginal crypts to seminal receptacles. Therefore, adult males are reproductive throughout the year and constitute a permanent resource for females, whereas females have extended, aseasonal reproductive cycles with an evidently discontinuous reproductive cycle with only one clutch per year.

Reproduction is an important aspect of the natural history of anuran species; it includes, for example, selection of the calling site by males, mate attraction, courtship, oviposition, and subsequent parental care. Among these, courtship is one of the least studied phases of anuran reproductive biology. Therefore, we describe for the first time the complex courtship of Bokermannohyla luctuosa, which involves tactile communication and two types of vocalizations: advertisement and courtship calls. These calls have a pseudo-pulsed structure, with the courtship call being similar to the advertisement call but longer in duration and lower in dominant frequency and relative peak power. Most of the behavioral repertoire of B. luctuosa courtship matches that reported for other Cophomantini species. Additional information on the natural history of phylogenetic closely related species, besides improving autoecological knowledge, will enable the recognition of behavioral synapomorphies for specific clades.