Habitats for pond-breeding salamanders are declining as a result of land development and management abandonment. In that context, a pond-breeding salamander Hynobius tokyoensis has recently been known to breed in small streams. However, little is known about the ecology of pond-breeding salamander larvae, such as food, in small streams. Here, to gain insight into foraging ecology of Hynobius tokyoensis larvae in small steams, we investigated the potential prey items in nine small streams running through secondary forests in Hachiouji City, Tokyo, Japan. In addition, we hypothesized that H. tokyoensis larvae preferentially predate active prey invertebrates over less-active prey because they are generalist, sit-and-wait predators. To test this hypothesis, we experimentally examined predation frequencies by H. tokyoensis larvae on the two major arthropod species (isopods and Plecoptera larvae) and activity (i.e., movement frequencies and distances) of the potential prey. As a result, isopods (Asellus hilgendorfii) and Plecoptera (Nemouridae larvae) are the two dominant aquatic invertebrates in small streams inhabited by H. tokyoensis, larval salamanders consumed more isopods than Plecoptera larvae and isopods are more active than Plecoptera larvae. Taken together, we concluded that isopods should be the main prey for salamander larvae inhabiting small streams due to their high abundance and conspicuous activities.
We sequenced mitochondrial cytochrome b gene of 14 samples of Siberian salamander, Salamandrella keyserlingii, from a population newly found in Kamishihoro-cho, eastern Hokkaido, Japan, and conducted phylogenetic analysis to reveal genetic identity of the population. The Kamishihoro population was most closely related to the geographically adjacent Kushiro population from Hokkaido, but possessed a single, unique haplotype. This result indicates that the Kamishihoro population is not an introduced, but a native population. Salamandrella keyserlingii is thought to have been once widespread throughout Sakhalin to Hokkaido, but the range was greatly narrowed subsequently in Hokkaido, with the divergence of the Kamishihoro and Kushiro populations at 0.34 MYBP, Middle Pleistocene.
A small, semi-arboreal toad of the genus Pelophryne from Peninsular Malaysia has been treated as P. brevipes or P. signata. The peninsular toad and Bornean P. signata are very similar to each other morphologically, although slightly different in relative forelimb length, dorsal coloration, and tuberculation. However, in partial mtDNA sequence, the peninsular toad is substantially distinct from P. signata from Borneo and P. brevipes from the Philippines, although it is close to a congener from Sumatra. Thus, the peninsular toad is described as a new species based on specimens from Genting Highlands, state of Pahang, central Peninsular Malaysia. Of the two morphotypes recognized in the genus, the new species belongs to the one with the tips of the fingers expanded into truncate discs, in which the new species is the smallest in body size. The new species also occurs in Singapore and possibly in Sumatra.
Despite being one of the world’s 25+ most endangered tortoises and freshwater turtles, the evolutionary history of the Vietnamese pond turtle (Mauremys annamensis) is largely unknown. This is due to the lack of wild, known-locality specimens for genetic studies. In this genetic study, we include four known-locality specimens of M. annamensis—two historical specimens (the lectotype and paralectotype of the junior synonym Annamemys merkleni), a living zoo specimen that was collected in 1966, and a contemporary, wild-caught specimen captured during intensive field surveys. We have three major findings regarding the genetics of M. annamensis and closely related species. First, with wild specimens from near the type locality, we identify mitochondrial and nuclear haplotypes for true M. annamensis. Second, we verify that M. guangxiensis is invalid due to its non-monophyly. Lastly, we verify that M. mutica from Anhui Province and Taiwan cluster genetically with samples from the type locality in Zhejiang Province. Despite these new data from known-locality specimens providing guidance for ex situ and in situ conservation efforts, some of the genetic patterns for M. annamensis and M. mutica defy obvious explanation and highlight the need for even more samples with reliable known provenance.
We report Lepidochelys olivacea from coastal waters of South Korea for the first time on the basis of two specimens (one male and one female) whose taxonomic identities were verified on morphological and molecular grounds. Four species of sea turtles, Dermochelys coriacea, Chelonia mydas, Caretta caretta, and Eretmochelys imbricata. have been recorded from South Korean waters, and present findings add another species to the sea turtle fauna of this region.
Partial skeletal remains of Mauremys reevesii, consisting of the right second and third costals of an individual, were discovered from late medieval deposit of an archaeological site in Hiroshima Prefecture, Japan. Because the site was a local port town with relatively frequent commercial exchanges then, the turtle may have possibly been brought there through direct or indirect foreign trade in the 15th Century. Current Japanese populations of M. reevesii have generally been considered as descendants of artificially transported individuals from outside Japan in no earlier than the late Edo period (late 18th Century). However, the present finding suggests that the species was actually introduced to Japan in the late medieval period or even earlier.
We isolated and characterized 11 microsatellite markers for Ovophis okinavensis, a viperid species endemic to the Ryukyu Archipelago. These markers showed polymorphism among 25 individuals from Okinawajima Island. The number of alleles per locus was 3–11, and observed and expected heterozygosity were 0.240–0.960 and 0.218–0.853, respectively. Cross-amplification confirmed that at least seven out of the 11 microsatellite markers were applicable to a putative relative, Trimeresurus gracilis. The markers provided here are expected to be valuable for population- and/or individual-level genetic studies of not only O. okinavenesis, but also its relatives.
We examined lines of arrested growth (LAG) in femurs from 20 individuals of the sand lizard Psammodromus algirus sampled from the north of Tunisia (North Africa). The number of the LAGs reached a maximum of three. The instant speed of linear growth in the first year was 6.6×10–2 mm/day and 3.76×10–2 mm/day the second year. The diameter of the marrow cavity was significantly larger in female (334.52 μm±115.68 μm) than in male (324.42 μm±114.2 μm). The growth rate observed in P. algirus followed the known growth pattern in lacertid lizards and the difference in the diameter of the marrow cavity between males and females may be related to a sexual dimorphism.
Many species of organisms are known to have expanded their distributional ranges and established highly dense populations in their non-native areas due to human activities. Several gecko species have been introduced from tropics to seasonal subtropics with the aid of artificial transportations. However, it has not yet been well-documented as to whether invasive tropical geckos flourish in extra-tropical cooler areas outside their native range. Here, I report demographic information of the mourning gecko, Lepidodactylus lugubris, in its northernmost distribution, the Ryukyu Archipelago in Japan. I conducted a mark-recapture survey of mourning geckos inhabiting a coastal vegetation habitat and estimated their population size using the Jolly-Seber open population model. An estimated 94–284 individuals lived in a small beachfront forest. The population showed a high density (880–2,656 geckos/ha), which is comparable to that of other invasive gecko populations in tropical areas. The results imply a successful colonization of clonal geckos at their northernmost invasion front.
Fejervarya kawamurai (Dicroglossidae) is an invasive species occurring in several populations in the Kanto region, including Fujisawa City, Kanagawa Prefecture, Japan. To estimate the ecological impacts of this frog, we investigated the food habits of invasive populations. We collected 119 individuals of F. kawamurai. Of these, 108 (90.8%) had stomach contents that included various small animals. Therefore, this invasive frog might influence the ecosystem via predation pressure on small native animals.