Taxonomic reappraisal of Hynobius tokyoensis, with description of a new species from northeastern Honshu, Japan (Amphibia: Caudata).

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.

Wide Distribution but Low Differentiation: Phylogenetic Relationships and Phylogeography of (Amphibia: Caudata).

We surveyed the genetic structure of Stejneger, 1907, a lentic breeding salamander widespread throughout montane and lowland regions of northeastern Japan. We performed a mitochondrial DNA analysis to explore intraspecific genetic variation and infer the evolutionary population history of . Complete 1141 bp sequences of the mitochondrial cytochrome gene were studied for 134 adult and larval individuals collected from 62 localities, encompassing the known range of the species.

Phylogeny and historical demography of Cynops pyrrhogaster (Amphibia: Urodela): taxonomic relationships and distributional changes associated with climatic oscillations.

We investigated the phylogenetic relationships and estimated the historical demography of the Japanese fire-bellied newt, Cynops pyrrhogaster, from Japanese mainlands using 1407-bp sequences of the mitochondrial DNA (NADH6, tRNAglu, cyt b) and 1208-bp sequences of nuclear DNA (Rag-1) genes. Phylogenetic trees based on mitochondrial DNA revealed four major haplotype clades (NORTHERN, CENTRAL, WESTERN, and SOUTHERN clades) within this species. Degree of genetic differentiation among major haplotype clades was very large for intraspecific variation, suggesting this species to be composed of four species lineages that replace each other geographically.

Allozymic variation in the Japanese clawed salamander, Onychodactylus japonicus (Amphibia: Caudata: Hynobiidae), with special reference to the presence of two sympatric genetic types.

We conducted an electrophoretic survey to examine geographic genetic variation in samples from 17 localities of the Japanese clawed salamander, Onychodactylus japonicus. This species was divided into six genetic groups (N-Tohoku, S-Tohoku, Tsukuba, SW-Honshu, Kinki, and Shikoku) that were largely concordant with clades or subclades recognized in our previous mtDNA study. Although the relationships among these six groups were not clarified, genetic distances between them were not small (mean Nel's D=0.

Morphological variation in a Japanese salamander, Hynobius kimurae (Amphibia, Caudata).

We studied variation in morphometric and meristic characters and color pattern in the salamander Hynobius kimurae, examining 282 males from 24 localities encompassing the whole distributional range of the species in Honshu, the mainland of Japan. Multivariate analyses of 24 morphometric characters resulted in the separation of two groups, (1) eastern populations from the Kanto District to Shizuoka Prefecture of the Chubu District, and (2) central-western populations from Aichi Prefecture of the Chubu District westwards. Similar groups were recognized in meristic characters and color pattern.

Systematic Relationships of Hynobius okiensis among Japanese Salamanders (Amphibia: Caudata).

We conducted an electrophoretic survey to examine systematic relationships of a lotic-breeding salamander Hynobius okiensis endemic to Dogo Island of the Oki Islands, Japan, with several lentic and lotic-breeding Japanese species. Genetically H. okiensis with 2n=56 chromosomes was closer to the lentic-breeding H.

Phylogenetic relationships and phylogeography of Hynobius tokyoensis (Amphibia: Caudata) using complete sequences of cytochrome b and control region genes of mitochondrial DNA.

Using complete sequences of cytochrome b (cyt b) and control region (CR; D-loop) genes of mitochondrial DNA, we investigated the phylogenetic relationships and phylogeography among populations of the salamander Hynobius tokyoensis in northern Japan. Inclusion of populations from Aichi, Chubu region within Hynobius nebulosus by previous results was confirmed because they formed a clade with H. nebulosus.

Karyotype of a Japanese salamander Hynobius katoi and its implication on breeding ecology (Amphibia: Caudata).

Karyotype of a Japanese small salamander, Hynobius katoi, was first described. All individuals examined had 2n=58 chromosomes, consisting of nine pairs of biarmed macrochromosomes, four pairs of biarmed medium-sized chromosomes, six pairs of biarmed microchromosomes, and 10 pairs of uniarmed microchromosomes, although distinction of the second and the third groups of chromosome pairs was not clear. All pairs appeared homologous and no sexual dimorphism was found.

A new species of salamander of the genus Hynobius from Central Honshu, Japan (Amphibia, Urodela).

We describe a small salamander from south Central Honshu, Japan, as a new species, Hynobius katoi. The genetic distances between this species and several named species, including sympatric H. kimurae, derived from allozyme data from a starch gel electrophoresis, proved to be sufficiently large to differentiate it at a specific rank.