Antipredator behavior of Cynops pyrrhogaster was observed in the field. A male, found in a temporal pool (11.7C), tightly coiled his body around the observer's finger (putative model of predator) when he was touched from lateral side. The body-coiling was formed both dextrally and sinistrally, depending on direction from which the newt's body was touched. Undulation of tail and noxious secretion accompanied the behavior. The coiling-around behavior was aborted immediately when the newt lost physical contact with finger. Apart from this, pushing on the head with a finger caused Unken reflex, which is commonly known as defensive behavior of newts. It is suggested that C. pyrrhogaster varies their defensive behavior depending on the situation of encounter with the predator.
We determined sequences of mitochondrial control region of 16 specimens of the leatherback turtles, Dermochelys coriacea, collected in the vicinity of Japan, and estimated stock origin of Japanese migrants. As a result, we found three haplotypes (JD1, 2, and 3) in these specimens, and 14 specimens possessed JD1. In comparison with previously reported sequences, JD1 and 2 were identical to a single haplotype endemic to West Pacific stock in New Guinea and Solomon Islands, whereas JD3 was identical to a haplotype nearly endemic to Malaysian stock. Our results indicate that most of the leatherbacks foraging around Japan originate in West Pacific stock, and a few may migrate from the Malaysian nesting population.
Previous phylogenetic studies based on mitochondrial DNA data have consistently suggested that Hynobius tokyoensis consists of two major clades, clade A (northern clade) and clade B (southern clade). In this study, we newly estimated their population genetic structure and phylogenetic relationships by nuclear SNPs, and the results suggested heterospecific relationships of the two mitochondrial clades, without present hybridization in between. They were also recognized as morphologically different. The type locality of H. tokyoensis is in Tokyo Prefecture, and therefore clade B corresponds to H. tokyoensis sensu stricto, leaving clade A without available scientific name. We, thus, describe the clade A from northeastern Kanto to southern Tohoku as a new species Hynobius sengokui. The new species is distinguished from H. tokyoensis by its relatively longer axilla-groin distance, shorter trunk, and deeper vomerine teeth series, and is estimated to have diverged from it during the late Pliocene.
Hybridizations on a secondary contact zone between 2 diverged lineages can have various evolutionary consequences, including the genetic replacement of one lineage by another. We detected such a case between 2 lineages (the Central and Western lineages) of the Japanese fire-bellied newt, Cynops pyrrhogaster in the Chugoku district of western Japan. We genotyped 269 individuals from 30 localities using the mitochondrial cytochrome b gene and 11 microsatellite loci. The mitochondrial DNA (mtDNA) analysis revealed that the 2 lineages were mostly distributed parapatrically to each other but co-occurred around the contact zone, whereas the microsatellite analyses indicated the presence of a hybrid zone. Geographic cline analysis revealed that the cline width of mtDNA is wider than the width of the microsatellite loci. The migration rate estimation and the NewHybrids analysis revealed that the Central lineage has expanded their range into the range of the hybrid zone, suggesting the possibility of range displacement of the 2 lineages as a consequence of the shift of their hybrid zone. We explored the process of asymmetric gene flow associated with the invasion of the Central lineage to explain this pattern.
We record a tree frog of the genus Liuixalus for the first time from outside of China and describe it as a new species, Liuixalus catbaensis, on the basis of a single juvenile specimen collected from Cat Ba Island, northern Vietnam. The new species is easily distinguished from all other members of the genus Liuixalus by its uniformly brick-red dorsum lacking dark markings. The biogeographical significance of finding of this species in Vietnam is briefly discussed.
Odorrana ishikawae is listed as a class IB endangered species in the IUCN Red List and is protected by law in both Okinawa and Kagoshima Prefectures, Japan. Here, in an effort to help effectively preserve the genetic diversity of this endangered species in the laboratory, we tested a farming technique involving the artificial breeding of frogs, and also promoted natural breeding in the laboratory. Field-caught male/female pairs of the Amami and Okinawa Island populations were artificially bred using an artificial insemination method in the 2004, 2006, and 2008 breeding seasons (March to April). Although fewer than 50% of the inseminated eggs achieved metamorphosis, approximately 500, 300, and 250 offspring from the three respective trials are currently being raised in the laboratory. During the 2009 and 2010 breeding seasons, second-generation offspring were produced by the natural mating activities of the first offspring derived from the two artificial matings in 2004. The findings and the methods presented here appear to be applicable to the temporary protection of genetic diversity of local populations in which the number of individuals has decreased or the environmental conditions have worsened to levels that frogs are unable to survive by themselves.
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.