Butterfly lizards of the genus Leiolepis Cuvier, 1829 are ground-dwelling lizards in the family Agamidae. In Thailand, widespread population declines occurred as the results of overhunting and anthropogenic habitat alteration. This was particularly apparent in the common butterfly lizard, Leiolepis belliana (Hardwicke & Gray, 1827). Despite numerous conservation efforts, fundamental knowledge regarding the population genetic structure and genetic diversity has been limited. This study utilized the mitochondrial cytochrome b gene to investigate the population genetic structure of L. belliana on islands in the eastern Gulf of Thailand, where both natural and introduced populations occur. Tail tissue samples were collected from nine island and mainland localities. Sequence analyses (n=59; 1,100 bps) revealed 11 haplotypes, with haplotype diversity (h) and nucleotide diversity (π) within each locality ranging from 0–0.867 and 0–0.0099, respectively. These values were comparable to those of other butterfly lizard species, but relatively high compared to other critically endangered lizard species. Significant genetic differentiation and distinct genetic structure were observed among populations on most of the islands. The phylogenetic tree depicted close genetic relationships between L. belliana specimens from the eastern Gulf of Thailand and those from southern Thailand, suggesting that the population genetic structure of L. belliana was shaped by both historical geographic events and human activities. These findings highlight the importance of genetic assessment in the formulation of conservation strategies by clearly defining conservation units and providing valuable insights into population genetic structure and variation.

The Japanese giant salamander, Andrias japonicus, is one of the largest extant amphibians. It is endemic to Japan and has been designated as a special natural monument by the Japanese government. The genus Andrias is also protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The Japanese giant salamander and one of the congeners, the Chinese giant salamander, A. davidianus, were recently found to hybridize in several areas in Japan, due to human-mediated introduction of A. davidianus. In this study, we found major differences in head and skull shapes between the Japanese and Chinese giant salamanders, using geometric morphometrics. The hybrids showed intermediate morphology between the two species, but also possessed a wider mouth, at the skeletal level, than either of the parent species. This unique characteristic of hybrids is suggested as one of the reasons for the current dominance of the hybrids in the introduced areas and may be an example of heterosis in urodeles.

This study aimed to clarify microhabitat use by the invasive green anole, Anolis carolinensis and four native lizard species on Zamami-jima Island, Japan. Daytime and nighttime field surveys were conducted at sites with (GAP) and without A. carolinensis (GAA). At the GAP sites daytime use of plant species, substrates and perch height by A. carolinensis differed from native lizards, whereas the parts of plants used by A. carolinensis were similar to those used by native lizards. The perch substrate types (plant parts, ground or artificial substrates) used by native lizards during the daytime differed slightly between the GAP and GAA areas. During the night, the resting plant species used by A. carolinensis differed from those used by the native lizards at the GAP area, although the plant parts and height above ground were similar to those used by the native lizards at the GAP area. In particular, Takydromus smaragdinus used Pennisetum purpureum leaves at a high frequency as a resting place in the GAA area. In contrast in the GAP area T. smaragdinus was never found resting on P. purpureum leaves while 77% of A. carolinensis were found resting on P. purpureum. These findings suggest that the overlap of microhabitats between A. carolinensis and native lizards is small during the daytime, but that this invasive lizard species influences the selection of resting sites by T. smaragdinus. Further studies are required to understand how A. carolinensis may exclude T. smaragdinus from resting sites.

The hawksbill turtle Eretmochelys imbricata is listed as “critically endangered” on the Red List of International Union for Conservation of Nature; it requires in situ and ex situ conservation. To establish an effective captive breeding technique for the hawksbill turtles, its reproductive parameters and behavior in captivity, and the physiological changes, including hormonal changes, that lead to egg laying must be understood. Here, we observed the mating behavior of male (n=5) and female (n=3) hawksbill turtles (housed in a tank) from 2003 to 2007. We regulated the tank water temperature and daylight hours to simulate their natural environment. We sampled their blood at regular intervals to measure plasma concentrations of minerals and sex hormones. One (No. Ei21) of the female turtles was reproductively more active than others. Further, males mounted it more frequently than others. Subsequently, the female (Ei21) laid eggs twice, on 10 May and 8 July 2003. Females including Ei21 showed annual changes in 17β-estradiol and progesterone (P4) levels, whereas males showed annual changes in testosterone levels. Plasma calcium (Ca) level peaked in only the egg laying turtle (Ei21); however, inorganic phosphorus did not show a sharp increase. In 2005, as in 2003, Ei21 underwent similar physiological changes. We conclude that this phenomenon—of rapid rise in plasma P4, a hormone elevated after ovulation, followed immediately by a rise in plasma Ca level—is likely involved in the eggshell formation after ovulation. In future, we will further investigate these phenomena in hawksbill turtles.

Selenium (Se) is naturally found in marine environments. At low concentrations, it causes both low hatching and emergence success in oviparous animals. The objective of this study was to compare serum Se concentrations between wild and captive hawksbill turtles, Eretmochelys imbricata, and investigate changes in Se concentration in turtles during captivity. Serum Se concentration was measured in 45 wild and captive hawksbill turtles. The mean Se concentrations in the serum of wild hawksbill turtles (x̄ ±SD=0.98±0.57 µg/g, n=16, range=0.18–2.61 µg/g) were significantly higher compared to those in captivity (x̄ ±SD=0.30±0.10, n=29, range=0.05–0.42). Serum Se concentrations remained almost constant irrespective of the rearing period and it began to decrease 1–2 years after rearing, which may result in low emergence success rates under managed care.

The sacroiliac joint, articulating the sacrum with the ilium, evolved in a common ancestor of tetrapods as they transitioned from aquatic to terrestrial environments. This skeletal connection between the hindlimb and the trunk plays an important role in terrestrial limb-driven locomotion. Nevertheless, the mechanisms underlying its formation remain almost unexplored. Urodeles are the best potential model group to study this mechanism because they show better preservation of ancient skeletal structures than other extant tetrapods, however, there have been no detailed descriptions of the developmental process of sacroiliac joint formation. We observed the skeletal development of the sacral rib and hindlimb bud-derived bones during the formation of the sacroiliac joint in the newt Pleurodeles waltl to identify the timing of the emergence of these bones. Based on these observations, we then performed hindlimb bud removal and transplantation experiments to examine the interaction between the developing sacral rib and limb bones. Removing either the left or both hindlimb buds from the larval body did not result in reduction of the size of the sacral ribs in this study, in contrast to previous studies which suggested effects of the hindlimb bud on sacral rib development. Autotransplantation of the excised hindlimb bud, either anteriorly or posteriorly, did not produce ectopic sacral rib-like structures on non-sacral vertebrae. Our results suggest that sacral rib development does not require the hindlimb bud.

The Upland Burrowing Tree Frog, Smilisca dentata, is classified as “Threatened” by the International Union for Conservation of Nature (IUCN) primarily due to its restricted distribution and the degradation of its habitat, despite the absence of quantitative analysis of its potential distribution and the impact of land use change on its habitat. In this study, we report four new population localities for the species. We estimated the extent of occurrence (EOO) and, utilizing a maximum entropy algorithm, the potential distribution area with ecological niche modeling (ENM). The potential distribution generated from abiotic (i.e., climatic) constraints was employed to quantify those areas with primary (natural, original) vegetation, areas with land use change due to anthropogenic impact, and the degree of fragmentation. We report four new localities for the species. The estimated EOO was 5,189.47 m² and the potential distribution with ENM was 29,390 m². However, this is reversed when land use change is considered, given the considerable reduction in the area of natural vegetation preferred by this treefrog. The distribution obtained by ENM is reduced, primarily due to the impact of agriculture. The amount of the potential distribution is reduced to 2,337 km² when the natural and secondary vegetation of Natural Grassland and Crasicaule Scrub are considered. But, if we only considered the natural vegetation, suitable habitat is drastically reduced to 472 km² and the habitat is described as fragmented and discontinuous. The findings of this study will help to accelerate the implementation of conservation measures for S. dentata.

Captive breeding programs are used worldwide to elucidate the natural history of endangered species and to recover and conserve their field populations. Kuroiwa's ground gecko, Goniurosaurus kuroiwae (Namiye, 1912) is an endangered species occurring in southern Japan; however, its mating behavior has not yet been described. We thus observed and quantified mating behavior of captive G. kuroiwae. Breeding trials with two males and three females resulted in 12 successful matings. Mating included precopulatory, copulatory, and postcopulatory stages, with 13 distinct mating behaviors observed. Behaviors indicative of successful copulation included the male preferentially biting the female's neck and the female approaching the male to initiate copulation. Mating behavior was initiated more than 10 h at night after cohabitation in some instances. These results suggest that at least one night of cohabitation is required for captive breeding of this species. Our findings thus contribute to conservation efforts by informing captive breeding programs.

We report two new localities of Hemiphyllodactylus montawaensis and one new locality of H. ngwelwini, located to the east of Taunggyi in Shan State, Myanmar. We collected five specimens from Site 1 and four specimens from Site 2. All specimens from Site 1 were identified as H. montawaensis, while Site 2 included three specimens of H. montawaensis and one specimen of H. ngwelwini. These represent the first record of the syntopic occurrence of these two species. These species were similar to each other in scalation but distinguishable by color pattern. Specimens of H. montawaensis from Site 1 did not show significant genetic differentiation from previously known localities, whereas those from Site 2 exhibited notable genetic differentiation. The new specimen of H. ngwelwini did not show significant genetic differentiation from previously known populations.