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Observations of reptile courting and mating behaviour are relatively scant in the literature. Here, using the largest sample of observed courting attempts and matings in tuatara (Sphenodon punctatus) ever published, we describe novel behaviours in this rare species: mirrored head bobbing between courting pairs, purring vocalizations by displaying males, and several potential instances of anejaculation in otherwise normal matings. These results highlight the complexity of reptile mating displays and have implications for how we manage this vulnerable species. [ABSTRACT FROM AUTHOR]

Little information for Eunectes beniensis (Dirksen, 2002) (Serpentes, Boidae) exists in the scientific literature and museum data. We review the natural history, diet, reproduction, distribution of this species and discuss its identifying characteristics. We present new records and discuss the species' distribution in Bolivia. As reported in the previous literature, the geographic locality data of the holotype and paratypes are incorrect. We report corrected data for these specimens and update knowledge of the species' distributional status and natural history by summarizing novel and existing data from the entirety of this species' known range. We provide a distribution map based on vouchered museum specimens. [ABSTRACT FROM AUTHOR]

Research in reproductive management of reptiles has focused on developing and investigating feasible methods that can be used in clinical practice and laboratory settings, including sexing in monomorphic species and methods of artificial insemination in endangered reptile species. In captive pet reptile species, research is focused on hormonal regulation of reproductive activity. Gonadotropin-releasing hormone (GnRH) agonist implants may temporarily suppress reproductive endocrine system (eg, circulating concentrations of estrogens and progesterone) in female green iguanas but did not influence male iguana behavior and plasma testosterone levels. Additionally, it did not suppress reproductive activity of females of other lizard species (eg, leopard geckos)., Competing Interests: Disclosure The author has nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Veiled chameleons (Chamaeleo calyptratus) are more frequently presented to veterinary clinics due to reproductive diseases that lead to high morbidity, especially in captive-bred females. The objective of this study was to evaluate blood biochemical profiles of healthy, young captive females veiled chameleons aged seven, nine and eleven months. Blood samples were taken from 20 female veiled chameleons at the age of 7, 9 and 11 months. The biochemical profile was analyzed using the VetScan VS2 analyzer with an Avian/Reptile Profile rotor. The ionized calcium (iCa) concentration was measured by i-STAT analyzer with a CHEM+8 cartridge. Mean concentration of glucose (15.8 ± 1.3 mmol/l) and uric acid (244.3 ± 143.2 µmol/l) at the age of seven months were significantly higher than mean concentrations of glucose (12.8 ± 16.5 mmol/l) and uric acid (134.9 ± 113.2 µmol/l) at nine months of age and mean concentration of glucose (13.2 ± 0.9 mmol/l) and uric acid (129.4 ± 109.2 µmol/l) at 11 months of age, respectively. Total calcium (4.2 ± 0.8 mmol/l) and ionized calcium (1.51 ± 0.16 mmol/l) were significantly higher at seven months of age compare to nin months. Mean activity of aspartate aminotransferase at nine months (6.2 ± 2.3 µkat/l) was significantly higher (P=0.004) than the mean activity of aspartate aminotransferase at seven months of age (4.7 ± 1.0 µkat/l). Concentrations of potassium at eleven months (8.3 ± 2.1 mmol/l) were significantly higher (P ˂ 0.001) than the mean concentration of potassium at seven months (5.4 ± 1.3 mmol/l) and also at ninth months (6.1 ± 1.6 mmol/l). No significant differences were found among the mean concentrations of total protein (57.5 ± 14.6, 61.9 ± 9.2, 59.6 ± 12.2 g/l), albumin (32.8 ± 5.4, 33.6 ± 4.1, 33.4 ± 7.1 g/l), globulin (27.4 ± 5.4, 26.6 ± 4.3, 26.3 ± 5.4 g/l) and mean activity of creatine kinase (25.4 ± 10.3, 30.1 ± 21.0, 25.6 ±13.2 µkat/l) at any of the ages. In all females, ovarian activity was already evident in the first part of monitoring, and the measured values could be interpreted as values for young female veiled chameleons during active ovarian activity. [ABSTRACT FROM AUTHOR]

This paper represents the results of a project on mass breeding of satanic leaf-tailed geckos (Uroplatusphantasticus Boulenger, 1888) in controlled laboratory conditions of BION Terrarium Center (Kyiv, Ukraine) in 2020. Given the growing popularity of U. phantasticus among hobbyists all over the world, it is important to develop a method of mass breeding of the species in conditions of herpetoculture. The work provides statistical data on the duration of gestation and incubation of eggs, obtained from a fairly large sample. The mean duration of gestation period for females (n = 119; exact counts of inter-clutch periods) was 34 days (min = 12, max = 64). The average duration of incubation was 94 days (min = 67, max = 130). The work also contains information on peculiarities of mating behavior, breeding ecology, copulation, percentage of infertile eggs and experience of maintaining a breeding stock with number of females exceeding that of males. Such information and its analysis are of particular scientific and practical value for the development of management plans for the conservation of the species, both in the wild and ex situ. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effectiveness of deslorelin acetate in the regulation of reproductive activity in captive leopard geckos (Eublepharis macularius). Fourteen healthy adult females were separated into two groups. Under general anaesthesia, deslorelin acetate implants (4.7 mg) or placebo implants were administered into the coelom of ten female geckos and four female geckos, respectively. One healthy adult male Leopard gecko was added to each group of females (five females with GnRH implants and two females with placebo implants). The geckos were regularly monitored over two breeding seasons (visual examination, weight control). Nesting sites were checked daily. There were no postoperative complications or any other health problems during the study. Implant administration did not result in long-term suppression of reproductive function. No significant differences were found in the number of clutches between the female groups (deslorelin implants versus placebo implants) or in the number of clutches between the two breeding seasons. Deslorelin acetate implants did not interfere with ovarian activity in captive female leopard geckos. The use of GnRH agonist implants is not an appropriate method for control of reproductive function in female leopard geckos.

Since the original description of Lycodon zawi almost two decades ago from Myanmar and Northeast India, little is known on the systematics, distributional range as well as the natural history of the species. Hence, this paper attempts to contribute updated information to enhance the genetic data, morphology, distributional records, and natural history on its feeding and the hitherto unknown breeding habit of this species from Mizoram State, Northeast India. [ABSTRACT FROM AUTHOR]

The development of analytical methods for the evaluation of crocodilian semen is an important component for the assessment of male breeding soundness and the development of assisted breeding technology in this taxon. Computer-Assisted Semen Analysis (CASA) technology is becoming an increasingly common technique in seminal evaluations for animals but there has been no application of this technique for reptilian spermatozoa. The aim of this study was to analyse sperm kinematic and morphometric variables in Caiman crocodilus fuscus semen samples and to determine whether there were sperm subpopulations. Four ejaculates from four sexually mature captive caimans were used for this study. A CASA-Mot and CASA-Morph system was used with an image acquisition rate of 50 Hz for 2 s of capture. The ISAS®D4C20 counting chambers were used and spermatozoa incubated at 25 °C. Total and progressive motilities did not differ among animals (P > 0.05). There was a significant animal effect in the model with respect to sperm morphometry, and kinematic indices including linearity (LIN) and straightness (STR) (P < 0.05). Results for principal component (PC) analysis indicated variables were grouped into four components: PC 1 related to velocity, PC 2 to progressivity, PC 3 to oscillation and PC 4 to sperm path cross-linking. Subpopulation (SP) structure analysis indicated there were four groups, namely, rapid non-progressive (SP 1), slow non-progressive (SP 2), rapid progressive (SP 3) and medium progressive (SP 4), representing 14.5%, 45.4%, 18.7%, and 21.4% respectively. Findings in the present study indicate the importance of continuing development of reliable protocols regarding the standardisation of computer-based semen analyses in reptilian species. [ABSTRACT FROM AUTHOR]

We report the Banded Racer Argyrogena fasciolata from the Coromandel Coast in peninsular India, where its occurrence remained doubtful. This is based on four specimens--two live, uncollected ones from Tambaram and Auroville, respectively, and two preserved specimens from Tuticorin. The sighting points span a distance of 500 airline km north-south across the eastern coastal plains. Both juvenile and adults were included in these records, which underscores that breeding populations exist in the regions dealt with. Our records highlight the need for faunal surveys even in reportedly depauperate or well-studied ecoregions, an element that points out a hidden diversity including species that are not ecologically cryptic. [ABSTRACT FROM AUTHOR]

High harvest rates during the 1900s led to declines of Macrochelys temminckii (Alligator Snapping Turtle) throughout much of its range. Recent research to determine the status of Alligator Snapping Turtles has been completed in some regions of Louisiana, but information is lacking for the southwestern region of the state. To determine the distribution and abundance of Alligator Snapping Turtles in southwestern Louisiana, we conducted trapping efforts in the lower Calcasieu, Mermentau, and lower Sabine river systems from March 2012 through October 2013 using baited hoop nets. In 731 trap nights, we captured 14 individuals (2 M, 4 F, 8 Juv) in the Mermentau and Calcasieu river systems. Our trapping efforts did not detect Alligator Snapping Turtles at Sabine River sites, although one individual was found dead on a fishing hook of a hanging limb line. Our catch per unit effort (CPUE) was 0.021 across the 3 river drainages. Population levels appear to be smaller than observed elsewhere in Louisiana and in neighboring southern states. We recommend that future surveys be conducted to determine population trajectories and that a system be implemented for monitoring commercial fishing bycatch and recrea tional harvest. [ABSTRACT FROM AUTHOR]

Although it is commonly assumed that female sea turtles always return to the beach they hatched, the pathways they use during the years preceding their first reproduction and their natal origins are most often unknown, as it is the case for juvenile green turtles found in Martinique waters in the Caribbean. Given the oceanic circulation of the Guiana current flowing toward Martinique and the presence of important nesting sites for this species in Suriname and French Guiana, we may assume that a large proportion of the juvenile green turtles found in Martinique are originating from the Suriname–French Guiana beaches. To confirm this hypothesis, we performed mixed stock analysis (MSA) on 40 green turtles sampled in Martinique Island and satellite tracked 31 juvenile green turtles tagged in Martinique to (a) assess their natal origin and (b) identify their destination. Our results from MSA confirm that these juveniles are descendant from females laying on several Caribbean and Atlantic beaches, mostly from Suriname and French Guiana, but also from more southern Brazilian beaches. These results were confirmed by the tracking data as the 10 turtles leaving Martinique headed across the Caribbean–Atlantic region in six different directions and 50% of these turtles reached the Brazilian foraging grounds used by the adult green turtles coming from French Guiana. One turtle left the French Guianan coast to perform the first transatlantic migration ever recorded in juvenile green turtles, swimming toward Guinea‐Bissau, which is the most important nesting site for green turtles along the African coast. The extensive movements of the migrant turtles evidenced the crossing of international waters and more than 25 exclusive economic zones, reinforcing the need for an international cooperative network to ensure the conservation of future breeders in this endangered species. We satellite tracked 31 juvenile green turtles tagged in Martinique Island, and performed mixed stock analysis on 40 green turtles sampled at the same site to assess their natal origin. Our results from mixed stock analysis confirm that these juveniles are descendant from females laying on several Caribbean and Atlantic beaches, mostly from Suriname and French Guiana, but also from more South Brazil. These results were confirmed by the tracking data showing that 50% of the tracked turtles reached the Brazilian foraging grounds used by the adult green turtles coming from French Guiana. [ABSTRACT FROM AUTHOR]

Despite the prevalence of sexual reproduction across eukaryotes, there is a remarkable diversity of sex‐determination mechanisms. The underlying causes of this diversity remain unclear, and it is unknown whether there are convergent trends in the directionality of turnover in sex‐determination mechanisms. We used the recently assembled Tree of Sex database to assess patterns in the evolution of sex‐determination systems in the remarkably diverse vertebrate clades of teleost fish, squamate reptiles and amphibians. Contrary to theoretical predictions, we find no evidence that the evolution of separate sexes is irreversible, as transitions from separate sexes to hermaphroditism occur at higher rates than the reverse in fish. We also find that transitions from environmental sex determination to genetic sex determination occur at higher rates than the reverse in both squamates and fish, suggesting that genetic sex determination is more stable. However, our data are not consistent with the hypothesis that heteromorphic sex chromosomes are an "evolutionary trap." Rather, we find similar transition rates between homomorphic and heteromorphic sex chromosomes in both fish and amphibians, and to environmental sex determination from heteromorphic vs. homomorphic sex chromosome systems in fish. Finally, we find that transitions between male and female heterogamety occur at similar rates in amphibians and squamates, while transitions to male heterogamety occur at higher rates in fish. Together, these results provide the most comprehensive view to date of the evolution of vertebrate sex determination in a phylogenetic context, providing new insight into long‐standing questions about the evolution of sexual reproduction. [ABSTRACT FROM AUTHOR]

Genetic analyses of nuclear DNA (e.g., microsatellites) are a primary tool for investigating mating systems in reptiles, particularly marine turtles. Whereas studies over the past two decades have demonstrated that polyandry (i.e., females mating with multiple males) is common in marine turtles, polygyny (i.e., males mating with multiple females) has rarely been reported. In this study we investigated the mating structure of Critically Endangered hawksbill turtles ( Eretmochelys imbricata ) at Bahía de Jiquilisco in El Salvador, one of the largest rookeries in the eastern Pacific Ocean. We collected genetic samples from 34 nesting females and hatchlings from 41 clutches during the 2015 nesting season, including one nest from each of 27 females and two nests from seven additional females. Using six highly polymorphic microsatellite loci, we reconstructed the paternal genotypes for 22 known male turtles and discovered that seven (31.8%) sired nests from multiple females, which represents the highest polygyny level reported to date for marine turtles and suggests that this is a common mating structure for this population. We also detected multiple paternity in four (11.8%) clutches from the 34 females analyzed, confirming polyandrous mating strategies are also employed. The high level of polygyny we documented suggests there may be a limited number of sexually mature males at Bahía de Jiquilisco; a scenario supported by multiple lines of empirical evidence. Our findings highlight key management uncertainties, including whether polygynous mating strategies can compensate for potential ongoing feminization and the low number of adult males found for this and possibly other marine turtle populations. [ABSTRACT FROM AUTHOR]

Lepidodactylus lugubris is an all-female parthenogenetic gecko. This gecko consists of diploid and triploid clones in the tropical and subtropical regions, and Clones A (diploid) and C (triploid) cohabit most islands in Ogasawara, Japan. On some Ogasawara islands, another cosmopolitan, but sexually reproductive, gecko Hemidactylus frenatus coexists with L. lugubris. This situation offers a unique opportunity to examine interactions not only between asexual female clones of L. lugubris but also between L. lugubris and both sexes of H. frenatus. We induced behavioral contests for food in small laboratory enclosures between two individuals of different clone, sex, and species combinations. Clone C interacted with other individuals less frequently and had a lower success in feeding the prey than Clone A and both sexes of H. frenatus. Clone C also showed few aggressive behaviors such as arches, growls, bites, and lunges, and never wrestled with other individuals. This interactive tendency of Clone C helps explain the microdistribution patterns of these sympatric geckos in the field. [ABSTRACT FROM AUTHOR]

The animal kingdom is represented by a spectacular diversity of colourful species. However, for particular groups, such as lizards, we still know little about the nature of these colours and what they might signal about individual quality. In eastern water dragons (Intellagama lesueurii), males are larger than females and have a red venter. We first identified the pigments responsible for the red coloration. We then used visual modelling to determine how conspicuous red colouration is to a dragon lizard. Finally, we asked whether colour signalled male morphology and whether parasitized males had reduced coloration. The red coloration of male water dragons is produced by both carotenoid and pteridine classes of pigments, but predominantly by drosopterin, a coloured pteridine. Heavy males with large heads and in good body condition and those with fewer ticks had less intense red coloration on the chest, abdomen and thighs. However, size was not correlated with any colour variables. We explain the negative relationship between colour conspicuousness and morphological variables by the fact that less conspicuous males might have more melanin interspersed with red. Future studies are needed to investigate the interplay between pteridines and melanin in social signals of male quality in dragon lizards. [ABSTRACT FROM AUTHOR]

Viviparity has evolved from oviparity at least 150 independent times in vertebrates. More than 80% of these transitions have occurred in squamate reptiles, where both reproductive modes are rarely seen in different populations of the same species. This condition (bimodal reproduction) is ideal for studying the physiological and morphological changes underpinning the evolution of reproductive mode, and their genetic determinants. Here we analysed the genomes of Zootoca vivipara populations with either oviparous or viviparous reproduction using a RAD sequencing approach. No signature of interbreeding between oviparous and viviparous individuals was found. We conservatively identified 22 annotated coding sequences in genes potentially associated with parity mode differences. Six of these genes are transcription regulators that are also expressed in reproductive tissues of mammals and reptiles, suggesting that changes in gene expression are important for the evolution of viviparity. Using a more inclusive approach based on contigs mapping in either coding or non-coding regions, 45 genes were identified. Twelve of these candidate genes are transcription regulators and four encode protease enzymes. We propose that the evolution of proteases may support morphological changes to the uterus during pregnancy. This study provides the foundation for further experimental studies of the genetic basis of parity mode in Z. vivipara. [ABSTRACT FROM AUTHOR]

Abstract: The consequences of individual variation in life‐history traits have been well studied due to their importance in evolutionary ecology. However, a trait that has received little empirical attention is the rate of indeterminate growth. In long‐lived ectotherms, subtle variation in growth after maturity could have major effects over the animals’ lifetimes. These effects are difficult to measure due to the challenges involved in reliably estimating individual variation in the face of environmental stochasticity, and the need to account for trade‐offs among growth, reproduction and survival. However, modelling advances have made such analysis possible if long‐term high‐quality datasets are available. We used an integrated state‐space modelling framework to reveal relationships between indeterminate growth, reproduction and survival in a population of North American snapping turtles (Chelydra serpentina) using a 41‐year dataset for 298 adult females. A hierarchical version of the von Bertalanffy model fitted to data on carapace lengths showed substantial individual variation in growth trajectories, and hierarchical models fitted to clutch‐mass data and recapture histories showed that reproductive output and survival probability increased with size. Integration of these models revealed no detectable trade‐offs—i.e., individual growth parameters were not correlated with size‐specific survival or reproduction rates, and individual variation in reproductive output did not affect the size‐specific survival rate. Consequently, individual variation in growth parameters was estimated to result in >2‐fold variation in post‐maturity life expectancy and >4‐fold variation in expected lifetime reproductive output. These results illustrate that indeterminate growth can have major fitness consequences in long‐lived species. We suggest that the individual variation in growth rates reflects variation in environments experienced during development or later life. An understanding of this variation may be essential for predicting the population dynamics of long‐lived species under threat and identifying the most important environments to protect. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

Abstract: Trade‐offs between the reproductive and immune systems are predicted when resources are limited, but are difficult to measure. We used 15N‐labelled amino acids to directly compare protein allocation by lizards to eggs and healing wounds. We showed that these two demands compete for the same resource, and that the ratio of protein allocation between them was related to body size, reproductive stage and plasma corticosterone levels. On average, rates of leucine deposition into eggs (0.022 μg/day) were an order of magnitude greater than those into scabs (0.002 μg/day), similar to leucine excretion rates (0.027 μg/day), and about half as large as leucine egestion rates (0.054 μg/day). We found that earlier reproductive stages and greater amounts of stored energy, but not manipulated food availability or the amount of food consumed, increased the absolute and relative allocation of protein to self‐maintenance. We provide direct evidence for amino acid trade‐offs between reproduction and wound healing. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

Reproductive aspects of most snake species remain elusive because of secretive habits or rarity. Here, we report data on litters of Crotalus triseriatus from two populations in central Mexico. We made 4-d visits to both study sites every other week from April to June during 2014 and 2015 (Site 1) and during 2015 (Site 2). Surveys were made from 0900 to 1800 h to catch as many gravid females as possible. All adult females were maintained in captivity until parturition. We recorded a total of 16 litters (10 from Site 1 and six from Site 2). Average litter size was 7.2 ± 2.2 ( n = 13), higher than previously reported in the species. We found no relationship between maternal snout-vent length (SVL) and litter size, and litter size did not differ between study sites or years. In contrast with other studies, we found no relationship between neonate SVL, body mass, and litter size or between maternal and neonatal traits. Dusky Rattlesnakes demonstrate a plastic reproductive response to changing environmental conditions. Neonate body size varied between sites, indicating that local selection may act through predation pressure, prey availability, or other environmental variables. Local selection may lead to differences in life history traits, whereas annual variation in factors such as prey availability might influence reproductive traits. Our study highlights the need for long-term studies to understand the sources of variation in life history. [ABSTRACT FROM AUTHOR]

In reptiles, the mode of reproduction is typically sexual. However, facultative parthenogenesis occurs in some Squamata, such as Komodo dragon (Varanus komodoensis) and Burmese python (Python bivittatus). Here, we report facultative parthenogenesis in the green anaconda (Eunectes murinus). We found two fully developed female neonates and 17 undeveloped eggs in the oviduct of a female anaconda isolated from other individuals for eight years and two months at Ueno Zoo, Japan. To clarify the zygosity of the neonates, we analyzed 18 microsatellite markers of which 16 were informative. We observed only maternal alleles and no paternal alleles for all 16 markers. To examine the possibility of the long-term sperm storage, we estimated allele frequencies in a putative parental stock by genotyping five unrelated founders. If all founders, including the mother, are originated from a single Mendelian population, then the probability that the neonates were produced by sexual reproduction with an unrelated male via long-term sperm storage was infinitesimally small (2.31E-32 per clutch). We also examined samples from two additional offspring that the mother delivered eight years before her death. We consistently observed paternal alleles in these elder offspring, indicating that the mother had switched from sexual reproduction to asexual reproduction during the eight years of isolation. This is the first case of parthenogenesis in Eunectes to be validated by DNA analysis, and suggests that facultative parthenogenesis is widespread in the Boidae. [ABSTRACT FROM AUTHOR]

The Chinese alligator Alligator sinensis is a critically endangered species endemic to China. Knowledge about reproductive strategies of a species contributes to their conservation. Little is, however, known about the reproductive strategies and its impact on the population. In the present study, an easy and non-invasive genetic method was used to improve the understanding of mating system of Chinese alligators and its effect on the population genetic diversity by nine polymorphic microsatellite loci. There was a high incidence of multiple paternity among 50 clutches, with a total 60% of the clutches having multiple paternity and up to three males contributing to single clutches. In addition, polyandry females choose to mate with males that are more distant in relatedness compared with monogamy females. Multiple paternity can decrease the inbreeding coefficient, while there is no significant difference between single and multiple paternity ( P > 0.05). Furthermore, there was an increased allelic diversity (though not heterozygosity) in multiple paternity sired offspring compared with the single paternity sired offspring in F2 generations ( P < 0.05), as predicted by the genetic diversity hypothesis. Multiple paternity may function as an important inbreeding avoidance compensation mechanism leading to the potential of the species to avoid extinction. These findings will not only enhance the understanding of the mating system and the biological traits of the Chinese alligator, but also improve the captive breeding program management and conservation strategies of the endangered species. [ABSTRACT FROM AUTHOR]

The giant South American river turtle (Podocnemis expansa) is the largest extant member of the suborder Pleurodira and the largest freshwater chelonian in South America. Owing to its size, its meat is sought for consumption and trade in the Amazon region. The aim of the present study was to investigate the reproductive behavior of 2 different populations of P. expansa. Allelic frequency variation was studied in 6 DNA microsatellite loci of recently hatched offspring from 8 nests on a beach in the municipality of Oriximina in the state of Para, Brazil. Multiple paternity was identified in all nests studied. Between 5 and 10 fathers contributed to each nest. Compared with previous studies, a greater frequency of multiple paternity and a greater number of fathers contributing to each nest were found in the present investigation. The results suggest that populations from different locations may exhibit different paternity patterns due to ecological or biological differences. By comparison with previous studies, we suggest that the differences in the number of nests, proportion of offspring per nest, and number of loci analyzed in each study may influence the frequency of multiple paternity detected. [ABSTRACT FROM AUTHOR]

We present here information on some fecundity parameters in local population of Eastern Hermann's tortoise situated in the area of Kunovica, at the outskirts of the city of Niš. The data were collected in the field and in 97% were based on reconstruction of number and dimensions of eggs in destroyed nests what influenced on quality of information. Only two of 78 nests recorded from 2010 to 2014 were found intact. Other 76 clutches were found destroyed and therefore only some fecundity parameters were measurable, while the others were reconstructed by using formulas proposed in the relevant literature. On the basis of collected data we estimated average clutch size of Hermann's tortoises in Kunovica as four eggs what was lower than in populations from Greece. However, the most of calculated egg dimensions (e.g. maximal width, volume and mass) were higher than in populations from Greece and France. [ABSTRACT FROM AUTHOR]

Background: DNA methylation alters gene expression but not DNA sequence and mediates some cases of phenotypic plasticity. Temperature-dependent sex determination (TSD) epitomizes phenotypic plasticity where environmental temperature drives embryonic sexual fate, as occurs commonly in turtles. Importantly, the temperature-specific transcription of two genes underlying gonadal differentiation is known to be induced by differential methylation in TSD fish, turtle and alligator. Yet, how extensive is the link between DNA methylation and TSD remains unclear. Here we test for broad differences in genome-wide DNA methylation between male and female hatchling gonads of the TSD painted turtle Chrysemys picta using methyl DNA immunoprecipitation sequencing, to identify differentially methylated candidates for future study. We also examine the genome-wide nCpG distribution (which affects DNA methylation) in painted turtles and test for historic methylation in genes regulating vertebrate gonadogenesis. Results: Turtle global methylation was consistent with other vertebrates (57% of the genome, 78% of all CpG dinucleotides). Numerous genes predicted to regulate turtle gonadogenesis exhibited sex-specific methylation and were proximal to methylated repeats. nCpG distribution predicted actual turtle DNA methylation and was bimodal in gene promoters (as other vertebrates) and introns (unlike other vertebrates). Differentially methylated genes, including regulators of sexual development, had lower nCpG content indicative of higher historic methylation. Conclusions: Ours is the first evidence suggesting that sexually dimorphic DNA methylation is pervasive in turtle gonads (perhaps mediated by repeat methylation) and that it targets numerous regulators of gonadal development, consistent with the hypothesis that it may regulate thermosensitive transcription in TSD vertebrates. However, further research during embryogenesis will help test this hypothesis and the alternative that instead, most differential methylation observed in hatchlings is the by-product of sexual differentiation and not its cause. [ABSTRACT FROM AUTHOR]

Leatherback turtles (Dermochelys coriacea) are capital breeders that accumulate blubber (33 kJ g-1 wet mass) by hyperphagia on a gelatinous diet at high latitudes; they breed in the tropics. A jellyfish diet is energy poor (0.1-0.2 kJ g-1 wet mass) so leatherbacks must ingest large quantities. Two published estimates of feeding rate [50% body mass day-1 (on Rhizostoma pulmo) and 73% body mass day-1 (on Cyanea capillata)] have been criticised as too high. Jellyfish have high salt and water contents that must be removed to access organic material and energy. Most salt is removed (as NaCl) by paired lachrymal salt glands. Divalent ions are lost via the gut. In this study, the size of adult salt glands (0.622 kg for a 450 kg turtle; relatively three times the size of salt glands in cheloniid turtles) was measured for the first time by computed tomography scanning. Various published values for leatherback field metabolic rate, body fluid composition and likely blubber accumulation rates are combined with known jellyfish salt, water and organic compositions to calculate feasible salt gland secretion rates and feeding rates. The results indicate that leatherbacks can produce about 10-15 ml secretion g-1 salt gland mass h-1 (tear osmolality 1800 mOsm kg-1). This will permit consumption of 80% body mass day-1 of C. capillata. Calculations suggest that leatherbacks will find it difficult/impossible to accumulate sufficient blubber for reproduction in a single feeding season. Rapid jellyfish digestion and short gut transit times are essential. [ABSTRACT FROM AUTHOR]

Basking is the primary mechanism used by many freshwater turtles to maintain their body temperature ( T b) in a range that maximizes physiological performance. Basking turtles are easily disturbed by motorboats, but the consequences of the increasingly popular use of motorboats on turtles is largely unknown., In this work, predictive models built from field and laboratory data were used to assess the effects of the frequency of basking disturbance by motorboats on T b and metabolic rate (MR) of female northern map turtles ( Graptemys geographica), a species of conservation concern., Simulations revealed that the effects of boat disturbance vary seasonally. In early May, a conservative estimate of the disturbance rate (0.15 per hour) resulted in a 0.34°C decrease in mean daily T b, which translated to a 7.8% reduction in mean MR. In June, July and August, owing to warmer lake temperatures, the effect of disturbance was less marked and the observed disturbance rates (0.32, 0.96 and 1.23 per hour, respectively) reduced the mean MR of an adult female by 2.1%, 0.5%, and 0.4 %, respectively., Reduction in MR decreases the rate of energy assimilation, which could translate into sublethal effects on turtles, such as reduced growth and reproductive output., Motorboat usage is increasing in many areas and is probably affecting other species of freshwater turtles that use aerial basking. This study offers important insights on the implications of disturbances for species that bask., Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Apoptosis is a tightly controlled process by which tissues eliminate unwanted cells. Spontaneous germ cell apoptosis in testis has been broadly investigated in mammals that have an associated spermatogenesis pattern. However, the mechanism of germ cell apoptosis in seasonally breeding reptiles following a dissociated spermatogenesis has remained enigmatic. In the present study, morphological evidence has clearly confirmed the dissociated spermatogenesis pattern in Pelodiscus sinensis. TUNEL and TEM analyses presented dynamic changes and ultrastructural characteristics of apoptotic germ cells during seasonal spermatogenesis, implying that apoptosis might be one of the key mechanisms to clear degraded germ cells. Furthermore, using RNA-Seq and digital gene expression (DGE) profiling, a large number of apoptosis-related differentially expressed genes (DEGs) at different phases of spermatogenesis were identified and characterized in the testis. DGE and RT-qPCR analysis revealed that the critical anti-apoptosis genes, such as Bcl-2, BAG1, and BAG5, showed up-regulated patterns during intermediate and late spermatogenesis. Moreover, the increases in mitochondrial transmembrane potential in July and October were detected by JC-1 staining. Notably, the low protein levels of pro-apoptotic cleaved caspase-3 and CytC in cytoplasm were detected by immunohistochemistry and western blot analyses, indicating that the CytC-Caspase model might be responsible for the effects of germ cell apoptosis on seasonal spermatogenesis. These results facilitate understanding the regulatory mechanisms of apoptosis during spermatogenesis and uncovering the biological process of the dissociated spermatogenesis system in reptiles. [ABSTRACT FROM AUTHOR]

The knowledge about reproductive strategies of a species contributes to their conservation. Multiple paternity is a reproductive behavior increasing effective population size, which could increase genetic diversity particularly in populations submitted to bottlenecks events. In Argentina, wild populations of Caiman latirostris are subject of a management plan devoted to their preservation and sustainable utilization based on its commercial interest. This program started in response to the evident numeric reduction of the populations, as a consequence of hunting pressure and habitat modification; it had a remarkable success in population recovery allowing the commercial use of C. latirostris. Data on reproductive behavior of C. latirostris are limited because mating occurs in the water and the information about their genetic diversity is scarce too. Our specific aims were to study the mating system and population genetic structure applying microsatellite markers in twelve C. latirostris families. The obtained results showed highly significant difference among populations and a lack of correspondence between geographical distance and genetic differentiation suggesting that populations of C. latirostris represent unstable metapopulations. In the paternity analysis was detected more than one father in two nests, which could be explained by capacity of storage sperm, proposed in females of a related species. The behavior of multipaternity could contribute to maintain viable populations of C. latirostris, since the maintenance of genetic variability within populations could help increase their capacity to respond to selective pressure. Further studies employing genetic and behavioral framework are needed to better understand the reproductive biology of C. latirostris. [ABSTRACT FROM AUTHOR]

Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter-limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit. [ABSTRACT FROM AUTHOR]

Gametogenesis studies are important to understand ecological and evolutionary processes. We report the first detailed description of spermatogenesis in amphisbaenians and describe the morphology of the male germ cells of Amphisbaena silvestrii and the organization of the germinal epithelium. We sampled the testes of 25 specimens and cut 3-μm thick sections. We then stained these sections by using 1% toluidine blue and photo-documented them. Testes are covered by the tunica albuginea that sends septa between the seminiferous tubules. The interstitial tissue is highly vascularized and consists of loose connective tissue with Leydig cells. Seminiferous tubules are coiled and coated with juxtaposed myoid cells. Sertoli cells and sperm series present a digitiform or pyramidal organization. We observed eight stages of development of the spermatids and the final maturation of spermatozoa during spermiogenesis. Further, we noted significant variation in the nuclear diameters of germ cells. This trait could be used to characterize germ cell types. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism ( SSD) evolves because body size is usually related to reproductive success through different pathways in females and males. Female body size is strongly correlated with fecundity, while in males, body size is correlated with mating success. In many lizard species, males are larger than females, whereas in others, females are the larger sex, suggesting that selection on fecundity has been stronger than sexual selection on males. As placental development or egg retention requires more space within the abdominal cavity, it has been suggested that females of viviparous lizards have larger abdomens or body size than their oviparous relatives. Thus, it would be expected that females of viviparous species attain larger sizes than their oviparous relatives, generating more biased patterns of SSD. We test these predictions using lizards of the genus Sceloporus. After controlling for phylogenetic effects, our results confirm a strong relationship between female body size and fecundity, suggesting that selection for higher fecundity has had a main role in the evolution of female body size. However, oviparous and viviparous females exhibit similar sizes and allometric relationships. Even though there is a strong effect of body size on female fecundity, once phylogenetic effects are considered, we find that the slope of male on female body size is significantly larger than one, providing evidence of greater evolutionary divergence of male body size. These results suggest that the relative impact of sexual selection acting on males has been stronger than fecundity selection acting on females within Sceloporus lizards. [ABSTRACT FROM AUTHOR]

Egg fertilization rate is a defining event in the life history of oviparous species. However, for many terrestrial oviparous species, this parameter is only estimated after hatching and emergence of hatchlings, by studying evidence of embryonic development in unhatched eggs. We compared the accuracy of this method with a second technique based on the careful excavation of sea turtle nests within the first 96 hours of oviposition and calculating the proportion of alive eggs, where a clear white spot is externally visible in the shell. Both methods underestimate the fertility rate but we are not aware of any other alternative on-invasive technique. The study was conducted in a nesting population of loggerhead turtles (Caretta caretta) at Boa Vista Island (Republic of Cabo Verde). We found significant differences in the estimation of fertilization rate between both techniques. When inspecting eggs after hatching, researchers significantly overestimated the number of unfertilized eggs and this calculation was not correlated with the estimation based on examination of eggs soon after oviposition. The first estimate was not correlated with hatching success or hatchling phenotype. There was no relationship between the number of viable embryos at oviposition and the hatching success and the hatchling's phenotype. The absence of embryo or its early death had no effect on survival of developing embryos within a nest. Fertilization rate in loggerheads did not show spatial or temporal variation during nesting season. We suggest the implementation in sea turtle nesting monitoring programs of annual less-invasive estimation of egg fertilization rate based on the excavation of a sample of representative nests immediately after the formation of the white spot in the shell of developing embryos. [ABSTRACT FROM AUTHOR]

Sexual steroids influence reproductive behaviours and promote secondary sexual traits. In male lizards, increasing levels of testosterone (T) bolster conspicuous colouration, stimulate territoriality, and trigger antagonistic interactions among rivals. Moreover, in colour polymorphic species, reproductive strategy, aggressiveness and T levels can differ between morphs. Therefore, T level is considered as an important mechanism that regulates the expression of colour polymorphism and sexual behaviours of males. But in the polymorphic territorial wall lizard (Podarcis muralis), a lack of relationship between morphs and aggressiveness challenges the notion that T plays such a role. To examine this issue, we compared adult T levels among three colour morphs (white, yellow and red) through repeated sampling during the mating season. High T levels were observed at the onset of the mating season followed by a significant decrease, a pattern documented in other lizard species. Mean T levels did not differ among morphs. However, yellow males maintained significantly higher T levels over time and displayed a stronger subsequent decline. Overall, in this species, seasonal T patterns differ among morphs, not mean values. Previous studies revealed that T suppresses the immune response; suggesting that a strong initial investment promoted by high T levels may trade-off against immunity (maintenance). Further experimental investigations are required to clarify the relationship between T and reproductive effort in polymorphic species that exhibit complex temporal pattern of T levels. [ABSTRACT FROM AUTHOR]

Examination of the geographical variation of selected morphological characters in Philodryas mattogrossensis resulted in evidence to support the recognition of two species and we therefore resurrect P. erlandi from the synonymy of P. mattogrossensis. Philodryas mattogrossensis inhabits Cerrado with some records in Atlantic Forest biomes in eastern Paraguay and southern Brazil, whereas P. erlandi is distributed in dry and arid environments of the Chaco in northern and western Paraguay, southeastern Bolivia, and northern Argentina. We designate SMF 49990 as neotype for Philodryas mattogrossensis. [ABSTRACT FROM AUTHOR]

Lifetime reproduction is a fundamental demographic variable for all vertebrate species, but rarely has been examined in snakes. In the southeastern Adirondack Mountains of New York, I used a capture-recapture method over a 36-yr period to study the lifetime reproductive biology of Crotalus horridus in a metapopulation of communal overwintering dens. These longitudinal data allowed analysis of the following parameters for many females throughout their reproductive lives: age and size at first reproduction, reproductive cycle length, duration and frequency of reproduction, body mass changes, and fecundity. Within the metapopulation, first reproduction occurred at a mean age of 9.6 yr, mean length of reproductive cycles was 4.2 yr, mean reproductive life span was 9.6 yr, and average fecundity was 7.7 offspring per litter. Nonviable offspring were observed in 20% of field litters. Although several female snakes produced multiple broods (as many as seven litters over spans as long as 32 yr), most females reproduced only once-the mean number of lifetime reproductive events was 1.7 efforts per female. During their gravid year, most females lost 2-3% of their initial mass, but gains and losses as great as 15-20% indicate feeding during gestation. Microgeographic differences were evident within the metapopulation and might be correlated with (1) resource levels that could influence growth rates, or (2) human encounters that could influence survival rates. Conserving C. horridus in its northern range depends on recognizing the importance of a suite of reproductive constraints-late age of maturity, long reproductive cycles, and low number of lifetime efforts-that clearly influence the viability and persistence of local populations. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effectiveness of deslorelin acetate in the regulation of reproductive activity in captive leopard geckos (Eublepharis macularius). Fourteen healthy adult females were separated into two groups. Under general anaesthesia, deslorelin acetate implants (4.7 mg) or placebo implants were administered into the coelom of ten female geckos and four female geckos, respectively. One healthy adult male Leopard gecko was added to each group of females (five females with GnRH implants and two females with placebo implants). The geckos were regularly monitored over two breeding seasons (visual examination, weight control). Nesting sites were checked daily. There were no postoperative complications or any other health problems during the study. Implant administration did not result in long-term suppression of reproductive function. No significant differences were found in the number of clutches between the female groups (deslorelin implants versus placebo implants) or in the number of clutches between the two breeding seasons. Deslorelin acetate implants did not interfere with ovarian activity in captive female leopard geckos. The use of GnRH agonist implants is not an appropriate method for control of reproductive function in female leopard geckos. [ABSTRACT FROM AUTHOR]

Chemical cues play an important role in sexual recognition in several lizard species. Here, we investigated whether the neotropical lizard, Liolaemus pacha (Iguania: Liolaemidae) can discriminate between chemical information obtained from males or females. In addition, we also considered the effect of season (reproductive vs. post-reproductive) and the sex of the tested individual. We experimentally tested scent discrimination, using a terrarium previously occupied by a male, a female, and an untreated terrarium as control as sources of different chemical scents. We counted the number of tongue flicks, a measure of chemical exploratory behavior, and the visual displays triggered by these scents for 10 min. Males performed significantly more tongue flicks when female scent was present than when male and control scents were present, indicating sexual recognition. However, females did not show a significant difference in those same conditions, indicating a lack of sexual recognition. For visual displays, males showed significantly higher rates to female and male scents than to control, whereas females did not show any difference. During the reproductive season, the number of tongue flicks and visual displays were higher than during the post-reproductive season. Our results suggest that for male L. pacha, chemical cues play an important role in mate recognition. We discuss the apparent lack of recognition in females. We suggest that the observed seasonal behavioral differences might be associated with physiological changes related mainly to reproduction. [ABSTRACT FROM AUTHOR]

To detect the small island effect ( SIE) and nestedness patterns of herpetofauna of the West Indies, we derived and updated data on the presence/absence of herpetofauna in this region from recently published reviews. We applied regression-based analyses, including linear regression and piecewise regressions with two and three segments, to detect the SIE and then used the Akaike's information criterion ( AIC) as a criterion to select the best model. We used the NODF (a nestedness metric based on overlap and decreasing fill) to quantify nestedness and employed two null models to determine significance. Moreover, a random sampling effort was made to infer about the degree of nestedness at portions of the entire community. We found piecewise regression with three segments performed best, suggesting the species-area relationships possess three different patterns that resulted from two area thresholds: a first one, delimiting the SIE, and a second one, delimiting evolutionary processes. We also found that taxa with lower resource requirement, higher dispersal ability, and stronger adaptation to the environment generally displayed lower corresponding threshold values, indicating superior taxonomic groups could earlier end the SIE period and start in situ speciation as the increase of island size. Moreover, the traditional two-segment piecewise regression method may cause poor estimations for both slope and threshold value of the SIE. Therefore, we suggest previous SIE detection works that conducted by two-segment piecewise regression method, ignoring the possibility of three segments, need to be reanalyzed. Antinestedness occurred in the entire system, whereas high degree of nestedness could still occur in portions within the region. Nestedness may still be applicable to conservation planning at portions even if it is antinested at the regional scale. However, nestedness may not be applicable to conservation planning at the regional scale even if nestedness does exist among sampling islands from a portion. [ABSTRACT FROM AUTHOR]

Historically, egg-bound reptile embryos were thought to passively thermoconform to the nest environment. However, recent observations of thermal taxis by embryos of multiple reptile species have led to the widely discussed hypothesis that embryos behaviorally thermoregulate. Because temperature affects development, such thermoregulation could allow embryos to control their fate far more than historically assumed. We assessed the opportunity for embryos to behaviorally thermoregulate in nature by examining thermal gradients within natural nests and eggs of the common snapping turtle (Chelydra serpentina; which displays embryonic thermal taxis) and by simulating thermal gradients within nests across a range of nest depths, egg sizes, and soil types. We observed little spatial thermal variation within nests, and thermal gradients were poorly transferred to eggs. Furthermore, thermal gradients sufficiently large and constant for behavioral thermoregulation were not predicted to occur in our simulations. Gradients of biologically relevant magnitude have limited global occurrence and reverse direction twice daily when they do exist, which is substantially faster than embryos can shift position within the egg. Our results imply that reptile embryos will rarely, if ever, have the opportunity to behaviorally thermoregulate by moving within the egg. We suggest that embryonic thermal taxis instead represents a play behavior, which may be adaptive or selectively neutral, and results from the mechanisms for behavioral thermoregulation in free-living stages coming online prior to hatching. [ABSTRACT FROM AUTHOR]

Viviparity has evolved at least 115 times in squamates and these multiple origins have raised a series of functional and evolutionary questions. Ideally, testing evolutionary hypotheses on squamate viviparity requires focusing on closely related taxa that exhibit both reproductive modes. South American water snakes of the tribe Hydropsini (genera Hydrops , Pseudoeryx , and Helicops ) are a potential model system for studying the evolution of viviparity. However, available information about reproductive modes in this group is often confusing and contradictory. Herein, we identify the reproductive modes of the Hydropsini species by combining original data taken from both museum and live specimens with a critical review of the published literature. In addition, we mapped the reproductive modes on different phylogenetic hypotheses to identify origins of viviparity. The genus Hydrops is exclusively oviparous. Contrary to previous suggestions, we found Pseudoeryx plicatilis to be oviparous, and available evidence suggests that females of the species remain with eggs throughout incubation. Our results show that reproductive mode varies only in the genus Helicops . Two Helicops species are oviparous and eight species are viviparous. Interestingly, we also found that one species ( Helicops angulatus ) exhibits both reproductive modes. Intraspecific variation in reproductive mode is a rare phenomenon in squamates, and H. angulatus is the only snake species in which reproductive bimodality has been confirmed. H. angulatus is oviparous from northern to mid-eastern and north-eastern South America, and viviparous from north-western to mid-western South America. The allopatric distribution of oviparous and viviparous forms of H. angulatus does not support the hypothesis of facultative changes in the reproductive mode. Geographic variation in the embryonic stage at oviposition is likely to occur in H. angulatus . Ancestral state reconstructions suggest that oviparity is plesiomorphic in Hydropsini, as well as in the bimodal genus Helicops , and that viviparity has evolved independently at least three times in Helicops . We argue that the water snakes of the tribe Hydropsini (and more importantly, the genus Helicops and the bimodal H. angulatus ) are an excellent model to test hypotheses on the evolution of squamate viviparity. [ABSTRACT FROM AUTHOR]

Comparative genomics approaches provide a means of leveraging functional genomics information from a highly annotated model organism’s genome (such as the mouse genome) in order to make physiological inferences about the role of genes and proteins in a less characterized organism’s genome (such as the Burmese python). We employed a comparative genomics approach to produce the functional annotation of Python bivittatus genes encoding proteins associated with sperm phenotypes. We identify 129 gene-phenotype relationships in the python which are implicated in 10 specific sperm phenotypes. Results obtained through our systematic analysis identified subsets of python genes exhibiting associations with gene ontology annotation terms. Functional annotation data was represented in a semantic scatter plot. Together, these newly annotated Python bivittatus genome resources provide a high resolution framework from which the biology relating to reptile spermatogenesis, fertility, and reproduction can be further investigated. Applications of our research include (1) production of genetic diagnostics for assessing fertility in domestic and wild reptiles; (2) enhanced assisted reproduction technology for endangered and captive reptiles; and (3) novel molecular targets for biotechnology-based approaches aimed at reducing fertility and reproduction of invasive reptiles. Additional enhancements to reptile genomic resources will further enhance their value. [ABSTRACT FROM AUTHOR]

The article discusses the life history of reptile species Crotalus cerastes, also known as female sidewinder based on development, reproduction, and lifespan. It presents tables about the reproduction history and figures of adult pairs that produces litters, its birth and offspring produce by female sidewinder. Topics include captivity study and husbandry of reptiles.

Lepidodactylus lugubris is one of the most widespread geckos distributed throughout tropical Asia and the Pacific, and some populations have been introduced to seasonal subtropical areas. On tropical islands, L. lugubris reproduces throughout the year, and it is considered potentially to be a continuous breeder. Generally reproduction in lizards is greatly affected by climate, and seasonality brings a cyclic reproductive pattern. Therefore, reproduction of invasive populations of L. lugubris in a seasonal subtropical area is likely to be affected by the climate there. In this paper, I report seasonal change in size distribution of L. lugubris in northern Okinawajima Island, Ryukyu Archipelago, Japan, where the species experiences a cold winter season. In early summer, most individuals were adults, and hatchlings did not exist. In autumn, both adults and hatchlings were found, and the size distribution was bimodal (a gap exists between two groups). The change of size distribution between the two seasons may be caused by the seasonal climate, and it suggests two non-exclusive possibilities: (1) cold winter may bring quiescence of reproduction, and (2) low temperature decreases hatching success of L. lugubris in northern Okinawajima Island. [ABSTRACT FROM AUTHOR]

In the last decade an increase in the accumulation of Sargassum has been reported throughout the Caribbean region. In 2015 these influxes caused serious impacts to marine turtles nesting and feeding areas, including Guanahacabibes Peninsula. This paper will focus on documenting all of the impacts caused by the influx of Sargassum fluitans in nesting beaches of marine turtles in Guanahacabibes Pensinsula, located on the western most tip of Cuba. To do so, photographic e vidence b out Sargassum distribution at the beach and the magnitud was gathered. At the same time nesting processes and hatching success were monitored. As a result, we found that loggerhead females were more affected than greens when they moved through the sargassum. In general, there was a desplacement of nesting activity almost exclusively to the sector of the beach between transects 12 and 15. Hatchlings were less affected since they began to hatch after the sargassum influx began to decrease. However, they had still had difficulties navegating the sargassum on their way to the open ocean. It is important to follow the trajectory and abundance of the sargassum masses to prevent future impacts on the coastal zone, especially, on marine turtle nesting areas and prevent it becoming a serious threat to nesting females and their hatchlings. [ABSTRACT FROM AUTHOR]

Almost all turtle species nest in terrestrial environments and maternal site selection represents a critical component of nest success. Females use cues in the current environment to predict the future conditions for embryo development. However, in disturbed landscapes, current and future conditions may not be correlated. We compared selection of nest sites by Blanding's Turtles (Emydoidea blandingii (Holbrook, 1838)) in a (relatively undisturbed) park and a (heavily disturbed) agricultural landscape in Ontario, Canada, using field measurements and satellite imagery. Environmental variables were compared using logistic regression and Akaike's information criterion (AIC) based on data measured at nest (presence) and random (pseudoabsence) locations. Specific environmental variables associated with site selection differed between study areas. Most notably, NDVI (normalized difference vegetation index, a proxy for vegetation cover) increased significantly during the year at the agricultural locale, corresponding with the growth of planted fields. No parallel change was observed at the park locale where canopy cover remained more consistent. An increase in vegetation cover may alter nest temperatures and soil moisture. Combined with the unpredictability in timing of crop sowing and harvesting, findings suggest that nests in agricultural fields may act as ecological sinks and that other species nesting in similarly altered habitats may be subjected to the same threats. [ABSTRACT FROM AUTHOR]

Studies regarding the effects of endocrine-disrupting chemicals (EDCs) on the reproductive functions of wild animals have raised increasing concern. Thus, here we evaluated the consequences of in ovo exposure to endosulfan (END) and bisphenol A (BPA) in testes from neonatal to juvenile (Juv) caimans (Caiman latirostris). Caiman eggs were collected from areas with low to moderate anthropogenic intervention and incubated at male-producing temperature. At stage 20 of embryonic development (previous to gonad sex determination), eggs were exposed to either END (20?ppm) or BPA (1.4?ppm) and male gonad histomorphology examined in 10-day-old, 90-day-old, and Juv caimans. The relative seminiferous tubular area (RTA) was measured in testes and the proliferation index and the expression of estrogen receptor alpha (ERa) were quantified in intratubular cells. Regardless of the treatment, all eggs resulted in male hatchlings. The testes of EDC-exposed caimans presented tortuous seminiferous tubules with empty tubular lumens. The RTA of 10-day-old caimans exposed to BPA was decreased. The percentage of cells expressing ERa was not different after in ovo treatment with EDCs (compared to the Control group), although caimans exposed to END showed a different ERa distribution pattern. The proliferation index was lower in 90-day-old caimans exposed to END, and higher in Juv caimans exposed to BPA. In ovo exposure to END or BPA modified sensitive parameters of C. latirostris male gonads. The alterations described here might compromise not only the sexual maturation but also the reproductive performance of adult caimans. [ABSTRACT FROM AUTHOR]

Bothrops insularis is an endemic and critically endangered snake with an estimated population of 2000 individuals restricted to Queimada Grande Island, in southeastern Brazil. Brazilian researchers established a captive breeding program for the species that includes the application of assisted reproductive technologies. The present study, therefore, aimed to evaluate semen samples from captive B. insularis throughout the year to ascertain seasonal differences in semen traits as well as correlations with body size and weight. Eighteen males with snout-vent length (SVL) ranging from 43.5 to 73.7 cm were collected at quarterly basis between August 2012 and May 2013. Macroscopic analysis revealed semen volumes ranging from 0.5 to 6.0 μL with samples featuring whitish to yellowish color and creamy and thick consistency. Viable sperm was obtained from all males indicating that individuals with SVL equal to or greater than 43.5 cm are sexually developed. However, adult and immature males (estimated by SVL) exhibited different seasonal profiles for motility and progressive motility. Adult males had a decrease in sperm motility and progressive motility during summer and spring, respectively, whereas the same variables did not vary throughout the year in immature snakes. Sperm concentration in all individuals was less (0.5 × 10 9 μL) during the winter, but no seasonal fluctuations were detected in semen volume. These findings are of particular importance to the development of reproductive tools such as male selection, artificial insemination and sperm freezing for the genetic management of this critically endangered snake. [ABSTRACT FROM AUTHOR]

Aim Although most reptiles are oviparous, viviparity is a common mode of reproduction in squamates and has evolved multiple times in different lineages. We test two prevailing hypotheses regarding the biogeography of reptile reproductive modes to evaluate the selective forces driving the evolution of viviparity in snakes. The cold climate hypothesis posits that viviparity is selected for in cold climates, whereas the climatic predictability hypothesis predicts that viviparity is advantageous in seasonal climates. Location Global. Methods We collated detailed distribution maps and reproductive mode data for 2663 species of the world's terrestrial alethinophidian snakes. We studied the relationship between snake reproductive mode and environmental predictors. We applied both an ecological and an evolutionary approach to study snake reproductive mode by performing the analyses at the assemblage level and species level, respectively. We analysed our data at the global and continental scales to learn whether tendencies to viviparity are similar world-wide. Results We found strong support for the cold climate hypothesis and the assumption that viviparity is an adaptation to cold environments. There was little support for the climatic predictability hypothesis. Nonetheless, viviparous species are not restricted to cold environments. Main conclusions We conclude that viviparity is adaptive in cold climates, but not necessarily in unpredictable/seasonal climates. Current distributions may not reflect the climate at the time and place of speciation. We suspect many viviparous snakes inhabiting warm climates are members of lineages that originated in colder regions, and their occurrence in maladaptive environments is a result of phylogenetic conservatism. [ABSTRACT FROM AUTHOR]