The Oita salamander Hynobius dunni Tago, 1931, endemic to eastern Kyushu and western Shikoku of southwestern Japan, is a lowland lentic breeder and has declined throughout its distribution range. To contribute to the future conservation of this salamander, current population genetic structures and genetic diversities were examined for 12 populations of eastern Kyushu, using a mitochondrial cytochrome b gene and three microsatellite loci. Populations were found to be genetically separated into northern and southern groups, and microsatellite analysis showed some genetic differences even in the northern regions. The southern group was restricted to a narrow area and had low genetic diversity in both mitochondrial and microsatellite DNAs. In the northern group, the mitochondrial and microsatellite DNA diversities were also low in some peripheral populations. For the accurate genetic management of this species, we need to pay more detailed attention to such genetic differentiation and diversity.
At least six local races of the Japanese fire-bellied newt, Cynops pyrrhogaster, have been reported (Atsumi, Hiroshima, Kanto, Sasayama, Tohoku, and Intermediate) on the bases of morphological and ethological traits. We observed mating behaviors of male newts collected from Gifu and Aichi Prefectures, Central Japan, in the range of the Intermediate race. Under captive conditions, almost all males put their hindlimbs on the scapular regions of their mates during courting by waving their tail. This behavior has been thought to be restricted to the Sasayama race from Kinki and Eastern Chugoku regions and the Atsumi race, presumably endemic to the Atsumi Peninsula of the Chubu region, but is now believed to be extinct. Our observations suggest that the Intermediate race occurring between the Sasayama and the Atsumi races also shares the same mating behavior characteristics. This observation concurs with the reported results of genetic analyses, which indicated the presence of little genetic isolation between the Sasayama and the Intermediate races.
We investigated phylogenetic positions of Cynops pyrrhogaster from nine localities in the central and southern parts of the Izu Peninsula using the mitochondrial cyt b gene. We revealed that the central and the southern populations are phylogenetically remote. The central Izu lineage belongs to the CENTRAL clade occurring from Chubu through Kinki to Chugoku districts, whereas the southern Izu populations form a lineage sister to the NORTHERN clade, which is distributed in Tohoku and Kanto districts. Genetic differentiation between the southern Izu lineage and the NORTHERN clade is relatively large with the uncorrected p-distance of 3.4%, which suggests their divergence at 3.31 MYA. This estimation indicates their genetic differentiation prior to 1.0 MYA, when the Izu Peninsula was formed through collision of a paleo-oceanic island with Honshu. These results indicate that the ancestor of the southern Izu lineage diverged from the NORTHERN clade somewhere in northern Honshu and then invaded the Izu Peninsula newly formed by collision and settled there. The central Izu lineage thereafter also invaded the peninsula, confining the range of the preceding southern Izu lineage to its current range.
A previous population genetic study using mitochondrial CO1 gene reported a Bornean dicroglossid frog Limnonectes leporinus to be highly diversified. However, our mtDNA phylogeny using samples collected from throughout the species distribution and longer sequences of 12S–16S rRNA genes indicates the species not markedly diversified within the island, conforming to the fact that it is also not diversified morphologically. The divergence times among local samples are thought to be younger than some congeneric species, and it is estimated that the species arose relatively new and subsequently rapidly dispersed within the island.
We describe a new species of Tylototriton from northwestern Vietnam and northern Thailand based on morphological and molecular evidence. Tylototriton anguliceps sp. nov. is distinguishable from all the other congeners by the bright to dark orange markings on the head, body, and tail, prominent dorsal and dorsolateral ridges (crests) on the head, skeletal connection between maxillary and pterygoid, and unique mitochondrial and nuclear DNA sequences. Our molecular data show that the new species is nested within the clade comprising T. uyenoi, T. shanjing, T. verrucosus, and T. yangi. The new species is expected to be recorded from other countries in the Indochina region such as southern China, western Myanmar and northern Laos in the future.
Animals communicating by sound face interference from biotic and abiotic sources. Contrasting strategies have been reported in different taxa in the presence of prolonged noise. Some torrent-living frogs of the genera Odorrana and Huia emit ultrasounds to avoid masking by environment noise. That strategy, however, might not be the only mode of acoustic communication for inhabiting along fast-flowing streams. To examine this possibility, we analyzed call structures of two horned toads, Megophrys kuatunensis and M. huangshanensis, which inhabit along streams in eastern China. We investigated variation in call properties within and between the two species and found that the two species show similar call structures but significantly differ in note duration and inter-note interval. Both of the two species concentrate energy on a single, wide harmonic band, and this might be an acoustic strategy against environmental noise.
The natural history of an animal provides crucial information for more focused studies in areas such as ecology, ethology, and evolution. Dinodon orientale is a small, nocturnal, and rather rare endemic species in Japan. Here we provide information on the natural history of D. orientale including information on seasonal activity pattern, body size, body mass, and body condition index associated with sex, based on 110 individuals captured in Yamanashi Prefecture, central Japan. Both sexes demonstrated a similar trend in the seasonal activity pattern and body condition. The seasonal activity peak of both sexes was in September, probably because hatchlings appeared in September. Body condition was high at the beginning and end of the active season and low in summer. We did not observe sexual dimorphism in snout-vent length (SVL) or body mass. The seasonal trend in the body size distribution of captured snakes suggests that hatchlings of D. orientale (of around 180 mm SVL) appear in September, grow to an SVL of about 250 mm by late October, and begin hibernation in November. Juveniles emerge in April or May and grow to an SVL of around 350 mm by late September.
We assessed taxonomic relationship of Tylototriton daweishanensis Zhao, Rao, Liu, Li and Yuan, 2012 and T. yangi Hou, Li and Lu, 2012 using mitochondrial DNA sequence data and found them to be as closely related as to be regarded as conspecific. This result, together with available morphological information, strongly indicates that T. daweishanensis is a junior synonym of T. yangi.
Ambystoma altamiranoi is an endangered endemic salamander found in the Transvolcanic Belt of Mexico. Unfortunately, relatively little is known about its ecology. Here we report on the diet of larval A. altamiranoi from a population in Llano de los Axolotes, Sierra de las Cruces, State of México, Mexico. Empty stomachs were found in 13.3% of individuals. Ostracods and gastropods dominated the diet of A. altamiranoi, together accounting for 89.9% of prey items consumed. The remainder of the diet consisted primarily of insects. Our observations suggest that the diet of A. altamiranoi is relatively narrow and that resources may be limited (relatively high frequency of empty stomachs), suggesting that factors that could impact the availability of ostracods and gastropods might have serious consequences for these endangered salamanders.
Glandirana susurra is an endemic species of ranid frog from Sado Island in northwestern Japan. Previous phylogenetic studies indicated that this species was nested within another Japanese congeneric species, G. rugosa, which itself also contained deep intraspecific genetic variations in mainland Japan. Thus, more detailed surveys of morphological variations in G. rugosa and G. susurra are needed. In this study, I report that G. susurra differs from G. rugosa in having a thin, pale brown ring around the pupil with a relatively wide gap at its dorsal extremity, a feature which is usually absent in G. rugosa. This character exhibited no geographic variations in G. rugosa. Since this character seems to be applicable to juveniles, it can be used as an additional diagnostic character to distinguish these two parapatric species.
Although most geckos are carnivorous, a number of examples of occasional observations on plant consumption have been reported in recent years. Moreover, previous research has reported that several Madagascan geckos lick honeydew excreted from planthoppers. Here, I report feeding on tree sap and honeydew by Geckolepis sp., a fish-scale gecko from northwestern Madagascar. Although, in the previous report, the planthopper showed specific abdomen movement after stimulation by a gecko, the planthopper and the gecko in my observation did not show any specific behavioral interaction. Honeydew milking without a specialized behavioral interaction, which was observed in Geckolepis sp., might be the intermediate stage of the evolutionary transition from simple feeding on plant sap to the highly specialized behavioral interaction that enhances honeydew milking.
Two species of the true frog genus Rana (R. japonica and R. ornativentris) are widely distributed on the main islands of Japan with some degree of habitat overlap. These species could be key indicators for environmental conditions and accurate identification is important. However, morphological characters in early stages of development are often insufficient to distinguish the two species, although their presence is often inferred from egg masses. Therefore, we developed a PCR-RFLP protocol for efficient and cost-effective identification of the species. We used a short partial 16S rRNA fragment (approx. 550 bp) and two diagnostic restriction enzymes (Spe I and Hph I) to identify species from DNA material. This approach allowed us to accurately assign all samples even without locality data. We also confirmed the performance of our method using another brown frog, R. t. tagoi.