We measured gaseous lift and specific gravity of larval anurans at regular intervals during development to assess their importance in determining buoyancy in eight species. Specifically, we examined the hatchling, larval, and metamorphic stages of tadpoles from still waters (Limnodynastes dumerili, Limn. peronii, Lithobates septentrionalis, and Rhinella marina), intermittent streams (Litoria genimaculata and Lito. lesueuri), and torrent sections of rivers (Lito. nannotis and Nyctimystes dayi). Buoyancy levels and the strategies used to attain buoyancy varied at different phases of development and with the environment occupied. Buoyancy increased rapidly during development in hatchlings of Limn. peronii, Lith. septentrionalis, and R. marina due to a reduction in specific gravity. Lungs were inflated in early larval stages of all species except for Lito. nannotis, N. dayi, and R. marina, which inflated their lungs following metamorphosis. Limnodynastes dumerili and Limn. peronii used gaseous lift to maintain near-neutral buoyancy throughout larval and metamorphic stages. Lithobates septentrionalis, Stages 25–29 (first summer), possessed a high level of gaseous lift, but buoyancy declined as lung gas volume decreased in Stages 31–43 (second summer). Rhinella marina did not inflate lungs prior to transformation but achieved an intermediate buoyancy level due to a very low specific gravity. The intermittent-stream species Lito. genimaculata and Lito. lesueuri used gaseous lift to achieve buoyancy levels similar to those of Lith. septentrionalis (Stages 31–43) and R. marina. The torrent-dwelling species Lito. nannotis and N. dayi were the least buoyant; their lungs were not inflated prior to transformation and their specific gravity was elevated. Both gaseous lift and specific gravity are important factors in determining buoyancy in larval anurans.

Previous studies showed that Fejervarya cancrivora tadpoles were salt-tolerant (up to 24 parts per thousand [ppt] in the field and 35 ppt in the laboratory) but metamorphosed only at or below 6.6 ppt. We hypothesized that the discrepancy in salt tolerance of tadpoles is due to a mixture of results drawn from short- and long-term experiments and different acclimation procedures, which needed to be re-examined. We compared the salinity tolerance of acclimated and nonacclimated tadpoles and assessed salinity effects on growth, development, and metamorphosis among tadpoles of F. cancrivora throughout larval period. In Experiment 1, we determined 48-h tadpole survivorship by assigning 40 tadpoles to one of the 24 treatments ranging from 3-ppt to 30-ppt salinity. In Experiment 2, we assigned tadpoles to 3–15-ppt salinity at intervals of 3 ppt and monitored tadpole growth and development through metamorphosis. In Experiment 3, we exposed 15 tadpoles to a stepwise increase of salinity (i.e., 2 ppt every 3 d) and monitored the tadpole survivorship and metamorphic success. From Experiment 1 we estimated an LC₅₀ (defined as the salt concentration that kills 50% of tadpoles within 48 h) of 13.7 ppt and tadpoles survived for 48 h at salinities as high as 16 ppt, suggesting that saline tolerance of F. cancrivora tadpoles is greater than all anuran species studied to date. Results of Experiment 2 showed that only tadpoles in 3, 6, and 9 ppt survived and reached metamorphosis. Tadpoles at 9 ppt grew and developed slower than in lower salinities during the first 7 wk, but the time to and size at metamorphosis were similar among treatments, suggesting that tadpoles were stressed at 9 ppt early, but they probably were able to maintain physiological homeostasis and to catch up growth after a period of adjustments. Results of Experiment 3 showed that all tadpoles survived through 18 d as the salinity was increased stepwise from 3 ppt to 15 ppt, and 6 out of 15 tadpoles were able to metamorphose at high salinities (17–21 ppt). This finding contradicts earlier results suggesting tadpoles could metamorphose only at salinities ≤6.6 ppt. Overall, our results showed that F. cancrivora tadpoles not only tolerate salt well, but also are capable of acclimation to higher salinities. This ability to acclimate could free tadpoles from dependence on the occurrence of rain to facilitate metamorphosis and thus, represents an adaptation to the unpredictable nature of salinity variation in brackish habitats.

Salinization of aquatic habitats is an emerging environmental concern, especially in colder climates where salt is used to prevent road icing during winter months. Salt applied to roads is carried into aquatic environments in storm-water runoff, where fluctuating water levels can result in salt stratification and spatially complex exposure scenarios for embryonic and larval pond-breeding amphibians. We conducted an experiment to investigate the potential interaction between oviposition site selection and toxicity of road salt to embryonic Cope's Gray Treefrogs (Hyla chrysoscelis). We simulated road-salt stratification in 7-L microcosms containing sediment from a salt-contaminated pond and placed developing eggs at three water depths and directly on the sediment of the microcosms. At the beginning of the experiment, conductivity at the bottom of the microcosms was four to seven (from ∼4.0 to 6.5 mS cm⁻¹) times higher than at the top or middle of the water column (∼1.0 mS cm⁻¹). Subsequently, survival of eggs placed near the bottom and on the bottom of buckets containing salt-contaminated sediment was near 0%, while survival of eggs at the top and middle depths of the contaminated microcosms, and at all depths in control microcosms, was >60%. After hatching, embryos avoided the bottom of contaminated buckets even though much of the vertical salt gradient had dissipated. In contrast, embryos in control buckets clustered at the bottom. Our results suggest that pond-breeding amphibians that place their eggs away from the bottom may avoid some of the toxic effects of salt contamination, and those that place eggs on the bottom may be at particularly high risk.

The Brazilian Ministry of the Environment (Ministério Do Meio Ambiente, MMA) proposed defining priority areas for Brazilian biodiversity conservation in 2007, but to date, no definitions of priority areas for amphibian conservation have been developed for the Caatinga biome or the semiarid region of Brazil. In this study, we searched for “hot spots” of amphibians in these two regions and assessed whether the priority areas established by the MMA coincided with those suitable for amphibian conservation. We determined amphibian hot spots by means of three estimates: areas of endemism, areas of high species richness, and areas with species that are threatened, rare, or have very limited distributions. We then assessed the degree of coincidence between amphibian hot spots and the priority areas of the MMA based on the current conservation units. We analyzed areas of endemism with the use of a parsimony analysis of endemicity (PAE) on quadrats. The Caatinga biome and semiarid region showed four and six areas of endemism, respectively, mainly associated with mountainous areas that are covered by isolated forests and positively correlated with species richness. All areas of endemism coincided with one or more priority areas defined by the MMA. We identify 15 priority areas for amphibian conservation in the Caatinga biome and semiarid region, including the creation of new full-protection conservation units.

This article describes the external and buccopharyngeal morphology, chondrocranium, and cranial muscles in tadpoles of Pleurodema thaul from Argentina. Further comparison was made with larvae of other Pleurodema species, particularly P. bufoninum. The larvae of P. thaul possess: (1) tooth row formula 2(2)/3(1), (2) single to double row of marginal papillae with wide rostral gap, (3) presence of long processus pseudopterygoideus, (4) pars alaris and pars corpora of the cartilago suprarostralis joined by both proximal and distal connections, and (5) larval processus oticus present. In the light of the available evidence, the larvae of Pleurodema are characterized by (1) medium size (total length  =  35.4–48.7 mm); (2) medium-sized tail (0.63 times of total length); (3) rounded snout; (4) nostrils closer to the eyes than to the snout; (5) vent tube opening medial; (6) tail tip rounded; and (7) oral disc subterminal with angular constrictions and rostral gap present. In Leiuperidae, the cartilaginous distal connection between pars alaris and pars corpora of the cartilago suprarostralis is present only in Pleurodema. In addition, all Pleurodema studied to date have processus pseudopterygoideus (shared with Eupemphix and Physalaemus marmoratus). Finally, within Pleurodema, the larval processus oticus is present only in P. thaul and P. bufoninum.

The recently erected chameleon genus Kinyongia currently includes 17 species, with the majority of this diversity occurring in montane regions of East Africa. Kinyongia adolfifriderici is one of only three species in the genus to occur in Central Africa, with numerous populations occurring from low- to high-elevation forests of the Albertine Rift. Recent fieldwork in the Lendu Plateau in northeastern Democratic Republic of the Congo (DRC) led to the discovery of a population of chameleons that is significantly larger than and morphologically distinct from the closely related species K. adolfifriderici, which was described from the lowland Ituri forest, DRC. Analyses of mitochondrial (16S and ND2) and nuclear (RAG1) DNA sequence data revealed that K. adolfifriderici is a complex of cryptic species. Herein, we describe the Lendu population as a new species, underscoring the endemism and conservation importance of this poorly known, unprotected montane region.

We examined the morphology and somatic growth rate of Green Sea Turtles living in San Diego Bay, California; one of the northern-most foraging areas for the species in the eastern Pacific. A power plant had discharged heated effluent into the urbanized bay from 1960 to 2010. Straight carapace lengths of 101 Green Sea Turtles were recorded from 31 March 1990 to 15 April 2011 (45.4 to 110.4 cm). Green Sea Turtles in San Diego Bay were morphologically indistinguishable from those foraging in Baja California Sur, Mexico. The median growth rate was 1.03 cm/yr (−1.6 to 11.4 cm/yr) for all turtles and was 4.9 cm/yr for turtles ≤90 cm. These growth rates were one of the fastest for the species in temperate areas and comparable to those reported for tropical regions. The estimated growth parameter of the von Bertalanffy growth function (mean growth coefficient  =  0.21, 95% posterior interval  =  0.19–0.23) also was greater than for other populations of Green Sea Turtles. Based on behavioral observations and information from other diet studies, we think that the altered environment from the power plant effluent affected the growth of the Green Sea Turtles directly (longer active periods) and via shifts in the environment (changes in prey composition, abundance, and distribution). With the termination of the power plant operation at the end of 2010, the ecosystem is reverting to its natural state, which we expect will result in decreased growth rates of these turtles in the coming years.

Vitamin E, vitamin A, and carotenoids are essential micronutrients for animals because of their antioxidant and immunostimulant functions and their implications for growth, development, and reproduction. In contrast to mammals and birds, information about their occurrence and distribution is generally lacking in reptiles, constraining our understanding of the use of these micronutrients. Using high-performance liquid chromatography, we determined the concentrations of vitamin E, vitamin A, and carotenoids in plasma, storage sites (liver and abdominal fat bodies), and in the colored ventral skin of male Common Lizards, Lacerta vivipara. All tissues shared a similar micronutrient profile, except the liver, which also showed traces of vitamin A₁. The main vitamin E compound present was α-tocopherol followed by lower concentrations of γ-(β-)tocopherol. Vitamin A₂ was the main vitamin A compound and it showed the highest concentration in the liver, where vitamin A₂ esters and traces of vitamin A₁ were found. Lutein was the main carotenoid, and it formed esters in the liver and the ventral skin. Zeaxanthin and low concentrations of β-carotene were also present. The liver was the main storage site for carotenoid and vitamin A, whereas hepatic vitamin E concentrations resembled those present in abdominal fat bodies. Compared with abdominal fat bodies, the ventral skin contained lower concentrations of vitamin A and vitamin E, but similar concentrations of carotenoids. These results suggest that important differences exist in micronutrient presence, concentration, and distribution among tissues of lizards and other taxa such as birds and mammals.

Liolaemus alticolor is redescribed herein, providing new character states that distinguish this taxon from all other members of the alticolor–bibronii group. Two new species of the alticolor–bibronii group are also described. One of the new species occurs in northern Argentina, in the Jujuy Province, whereas the other occurs in southern Argentina, in the Neuquén Province (northern Patagonia). Both of them exhibit characters that distinguish them from each other and from all other members of the alticolor–bibronii group. A key to the species of this group is provided.

In this study, we describe a new taxon for the genus Phymaturus from the Sierra Laguna Blanca, Catamarca Province, Argentina. This area is known to be an isolated part of the Puna region where other endemic species of vertebrates occur. This new species of lizard belongs to the palluma group because it exhibits juxtaposed superciliary scales, rugose caudal scales, and typically a fragmented subocular scale. Also, this new Phymaturus is assignable, within the palluma group, to the northern or Puna clade because it presents the typical “spray” pattern and brown tails in males, which are distinct from the dorsal-reticulated pattern and yellow tails in species of the southern palluma group. It differs from its relatives in the Puna clade by having the following combination of characters: scapular spot present (more conspicuous in juveniles and females), yellow color in flank of females, males without enlarged scales on ventral surface of the base of tail, males with dark brown throat, enlarged scales on borders of posterior gular fold inconspicuous, ringed tails in both sexes, incomplete pigmentation over dorsum of neck, diffuse white transverse stripes over dorsum of body in females, absence of vertebral stripe, and in some specimens a divided rostral scale. Finally, we present new characters to be considered in future studies of Phymaturus systematics.

The loss and fragmentation of pristine habitat restrict specialized species to remnants of original habitat patches in a less suitable landscape. This may lead to a genetic differentiation of the subpopulations and to a decline in biodiversity. We used seven microsatellite markers to examine the genetic population structure of the Grass Snake, Natrix natrix, sampled in remnants of pristine habitat in a former wetland in the Swiss lowlands and in a rural valley in the Alps. On a regional level, the population structures of N. natrix in these two areas were compared with that of Grass Snakes living in an intensively used agricultural area. The three study areas were 30–100 km apart, but were interconnected by the river Aare. At the local scale, no genetic differentiation was found in either of the N. natrix populations inhabiting the rural alpine valley or the intensively used agricultural area. However, two subpopulations in the former wetland area were genetically differentiated with a low but significant measure of genetic differentiation between subpopulations, F_ST. This slight genetic differentiation can be explained by isolation by distance. At the regional scale, we found significant genetic differentiation between N. natrix populations inhabiting areas separated by 30–100 km. The genetic structure was highly related to isolation by distance with 85% of the among-populations genetic variance explained by the geographical distance between subpopulations. Euclidean distance explained genetic differentiation of Grass Snake populations better than the distance following watercourses. Our findings indicate regular gene flow between N. natrix subpopulations and show that this species also moves across intensively used terrestrial habitat. The genetic structure of Grass Snakes is mainly affected by geographic distance, while human activity and habitat alteration do not seem to reduce the snakes' movements. Our results suggest that conservation actions in landscapes altered by humans should focus on the maintenance of a habitat mosaic with anuran breeding ponds and adequate oviposition sites.