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Masafumi Matsui - One of the best experts on this subject based on the ideXlab platform.

  • wide distribution but low differentiation phylogenetic relationships and phylogeography of Hynobius nigrescens amphibia caudata
    Zoological Science, 2020
    Co-Authors: Masafumi Matsui, Gen Aoki, Shingo Tanabe, Natsuhiko Yoshikawa, Koji Sasamori, Masamichi Matsui, Yasuchika Misawa, Kanto Nishikawa
    Abstract:

    We surveyed the genetic structure of Hynobius nigrescens 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 H. nigrescens. Complete 1141 bp sequences of the mitochondrial cytochrome b gene were studied for 134 adult and larval individuals collected from 62 localities, encompassing the known range of the species. Hynobius nigrescens proved to be monophyletic, including two major clades (Clade II from southwestern Hokuriku and Clade I from all other localities). The latter clade comprises four well-supported and geographically structured subclades, which show genetic distances smaller than those seen in the widely sympatric species Hynobius lichenatus. Results of population statistical analyses indicated that Clade II of the westernmost range of H. nigrescens seems to have maintained a constant population size, while Clade I from most of the northeastern species range shows a tendency of recent population expansion, which is evident in Subclades I-A from the northernmost range and I-B from southern Tohoku to northern Kanto and eastern Chubu. In contrast, Subclades I-C from northeastern Chubu and Sado Is. and I-D from northwestern Chubu to Hokuriku seem to have been relatively stable in population size. Hynobius nigrescens differs greatly from other salamander species from northeastern Japan in its much more recent periods of genetic differentiation and its pattern thereof, and is suggested to be a young faunal element in this region.

  • a revision of Hynobius stejnegeri a lotic breeding salamander from western japan with a description of three new species amphibia caudata hynobiidae
    Zootaxa, 2019
    Co-Authors: Atsushi Tominaga, Shingo Tanabe, Masafumi Matsui, Kanto Nishikawa
    Abstract:

    A lotic-breeding salamander Hynobius stejnegeri, formerly called H. yatsui, from western Japan is revised based on genetic and morphological evidence, and three species are described: H. guttatus sp. nov. from Chubu-Kinki districts of Honshu Island, H. tsurugiensis sp. nov. from east highland of Shikoku Island, and H. kuishiensis sp. nov. from other parts of Shikoku Island. Thus, H. stejnegeri sensu stricto is restricted to Kyushu Island. Of these four species, H. kuishiensis sp. nov. contains two distinct mitochondrial lineages, but this split is not reflected in differentiation of allozyme (nuclear genome) markers. These species are morphologically similar to each other but can be differentiated by several characteristics, especially in combination of dorsal coloration, the number of vomerine, upper, and lower jaw teeth, and depth of vomerine teeth series. In coloration, H. guttatus sp. nov. is brown or dark brown mostly with tiny white to brownish white marking, while H. tsurugiensis sp. nov. is dark brown with bright yellow continuous markings. Hynobius kuishiensis sp. nov. is reddish purple or dark brown with small to continuous brownish white markings, in contrast to reddish purple or dark brown with small to large brownish white markings in H. stejnegeri.

  • systematics of the widely distributed japanese clouded salamander Hynobius nebulosus amphibia caudata hynobiidae and its closest relatives
    Current Herpetology, 2019
    Co-Authors: Masafumi Matsui, Kanto Nishikawa, Gen Aoki, Shingo Tanabe, Natsuhiko Yoshikawa, Yasuchika Misawa, Hiroshi Okawa, Koshiro Eto, Atsushi Tominaga
    Abstract:

    The abundant clouded salamander from western Japan, Hynobius nebulosus, has long been considered a single widespread species, although some authors have suggested the inclusion of several cryptic species. This led to a molecular and morphological analysis of populations from all parts of the known range. Phylogenetic relationships were inferred from complete sequences of the mitochondrial cytochrome b gene, and nuclear genome differentiations were estimated by multiplexed inter simple sequence repeat genotyping by sequencing (MIG-seq). The results suggest that H. nebulosus hitherto recognized consists of at least nine species. We applied existing names to two of them, H. nebulosus (Temminck et Schlegel) and H. vandenburghi Dunn, and described seven others as new species.

  • two new species of lotic breeding salamanders amphibia caudata hynobiidae from western japan
    Zootaxa, 2019
    Co-Authors: Atsushi Tominaga, Masafumi Matsui, Kanto Nishikawa
    Abstract:

    Two new species of lotic-breeding salamanders, Hynobius sematonotos and H. oyamai, are described from Chugoku district and northeastern Kyushu district, respectively, western Japan. They are members of the so-called H. naevius group and are phylogenetically close to H. naevius, H. katoi, and H. hirosei but divergent from them with large genetic distances. These new species have been treated as Chugoku and northeastern Kyushu lineages, respectively, of H. naevius to which they are morphologically very similar. However, these new species can be differentiated from H. naevius by several morphological traits. Hynobius sematonotos is characterized and discriminated from other species by combination of small body size, a shallow vomerine teeth series with small number of vomerine teeth, small number of upper and lower jaw teeth, relatively long head and snout, and large upper eyelid, relatively short axilla-groin, reddish purple ground color with grayish brown marking on the dorsum, and reddish to bluish gray ventral ground color with relatively large markings varying from pale-white to white. Hynobius oyamai is characterized and discriminated from other species by large body size, moderately deep vomerine teeth series with a medium number of vomerine teeth, large number of upper and lower jaw teeth, relatively wide internarial and long fifth toe, bluish purple ground color sometimes with pale white marking on dorsum. Hynobius sematonotos occurs in Honshu, disjunct from H. naevius and H. oyamai that occur allopatrically in Kyushu.

  • taxonomic relationships of Hynobius stejnegeri and h yatsui with description of the amber colored salamander from kyushu japan amphibia caudata
    Zoological Science, 2017
    Co-Authors: Masafumi Matsui, Kanto Nishikawa, Atsushi Tominaga
    Abstract:

    Examination of the holotype of Hynobius stejnegeri Dunn, 1923 revealed that the species is identical with H. yatsui Oyama, 1947, recently resurrected from H. naevius (Temminck and Schlegel, 1838). The name H. yatsui is therefore relegated to a subjective junior synonym of H. stejnegeri. The latter name, however, has been widely applied to an amber-colored or tortoise-shell salamander from Kyushu, southwestern Japan, which now requires a new name. We, thus, describe the ambercolored salamander as a new species Hynobius ikioi. The new species is phylogenetically very close to H. amakusaensis Nishikawa and Matsui, 2014 and H. osumiensis Nishikawa and Matsui, 2014, both also from Kyushu, but is easily distinguished from them by its uniquely bi-colored dorsum.

Kanto Nishikawa - One of the best experts on this subject based on the ideXlab platform.

  • osteological characteristics of the setouchi salamander Hynobius setouchi urodela hynobiidae
    Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 2021
    Co-Authors: Sotaro Hara, Kanto Nishikawa
    Abstract:

    This study described the detailed osteological features of the Setouchi salamander Hynobius setouchi. H. setouchi, which is endemic to central Japan, was recently delineated from the wide range of H. nebulosus species based on molecular and external morphological characteristics. However, the osteological features of the species belonging to the genus Hynobius have not been examined, which has hindered the detailed understanding of morphological diversity in the genus. To address this problem, this study elucidated the osteological features of the salamander using micro-computed tomography scanning and whole-mount double staining methods. The articular, a part of the hypobranchial I, a part of coracoid, pubis, carpus, and tarsus were cartilaginous in small-sized individuals and were partially or completely ossified in large-sized individuals. The degree of ossification varied in the operculum, basibranchial II, and ascending process of the palatoquadrate. However, ossification was not associated with body size. The lacrimal, ossified manus, and ossified pes exhibited varying degrees of articulation or fusion irrespective of body size. Moreover, the cranium and tarsus of H. setouchi exhibited several unique characteristics. These osteological characteristics will aid in revising the taxonomy and phylogeny of the Hynobius species.

  • discovery of two lineages of Hynobius tsuensis amphibia caudata endemic to tsushima island japan
    Zoological Science, 2021
    Co-Authors: Keita Niwa, Masaki Kuroo, Kanto Nishikawa
    Abstract:

    The Tsushima salamander, Hynobius tsuensis, is a lotic-breeding species endemic to Tsushima Island, Japan. We investigated genetic variation in this species using samples covering all known localities on the island. Phylogenetic analyses based on mitochondrial cytochrome b gene sequences divided H. tsuensis populations into two genetic groups: true H. tsuensis and an unknown species (Hynobius sp.) showing a closer relationship to Hynobius nebulosus than to H. tsuensis. The genetic distance between the two groups was greater than the genetic distances between different species of Hynobius. Both groups were found to breed in mountain streams, sometimes in the same streams syntopically. Population structure analysis based on several nuclear microsatellite loci strongly indicated reproductive isolation between the two groups in the syntopic localities. This is the first report confirming the syntopic occurrence of two lotic salamanders of Hynobius on a small island. We propose that the lotic breeding habits of the two salamanders were independently acquired.

  • wide distribution but low differentiation phylogenetic relationships and phylogeography of Hynobius nigrescens amphibia caudata
    Zoological Science, 2020
    Co-Authors: Masafumi Matsui, Gen Aoki, Shingo Tanabe, Natsuhiko Yoshikawa, Koji Sasamori, Masamichi Matsui, Yasuchika Misawa, Kanto Nishikawa
    Abstract:

    We surveyed the genetic structure of Hynobius nigrescens 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 H. nigrescens. Complete 1141 bp sequences of the mitochondrial cytochrome b gene were studied for 134 adult and larval individuals collected from 62 localities, encompassing the known range of the species. Hynobius nigrescens proved to be monophyletic, including two major clades (Clade II from southwestern Hokuriku and Clade I from all other localities). The latter clade comprises four well-supported and geographically structured subclades, which show genetic distances smaller than those seen in the widely sympatric species Hynobius lichenatus. Results of population statistical analyses indicated that Clade II of the westernmost range of H. nigrescens seems to have maintained a constant population size, while Clade I from most of the northeastern species range shows a tendency of recent population expansion, which is evident in Subclades I-A from the northernmost range and I-B from southern Tohoku to northern Kanto and eastern Chubu. In contrast, Subclades I-C from northeastern Chubu and Sado Is. and I-D from northwestern Chubu to Hokuriku seem to have been relatively stable in population size. Hynobius nigrescens differs greatly from other salamander species from northeastern Japan in its much more recent periods of genetic differentiation and its pattern thereof, and is suggested to be a young faunal element in this region.

  • intraspecific variation in the external and skeletal morphology of Hynobius setouchi matsui okawa tanabe et misawa 2019 amphibia urodela hynobiidae
    Zoological Science, 2020
    Co-Authors: Sotaro Hara, Kanto Nishikawa
    Abstract:

    The hynobiid salamander genus Hynobius is a basal taxon in the urodeles that plays a key role in understanding the evolution of sexual dimorphism in urodeles. We examined the age (juveniles vs. adults) and sexual differences in the external and skeletal morphology of a Japanese lentic breeding salamander, Hynobius setouchi. We found that juveniles had larger heads than those of adults, and most characters were larger in adult males than in females, except for trunk size. This was also observed in skeletal morphology, although some tail characters differed only in the skeleton. We suggest that intra- and interspecific comparisons of the external and skeletal characters of salamanders should consider age, sexual, and seasonal differences.

  • a revision of Hynobius stejnegeri a lotic breeding salamander from western japan with a description of three new species amphibia caudata hynobiidae
    Zootaxa, 2019
    Co-Authors: Atsushi Tominaga, Shingo Tanabe, Masafumi Matsui, Kanto Nishikawa
    Abstract:

    A lotic-breeding salamander Hynobius stejnegeri, formerly called H. yatsui, from western Japan is revised based on genetic and morphological evidence, and three species are described: H. guttatus sp. nov. from Chubu-Kinki districts of Honshu Island, H. tsurugiensis sp. nov. from east highland of Shikoku Island, and H. kuishiensis sp. nov. from other parts of Shikoku Island. Thus, H. stejnegeri sensu stricto is restricted to Kyushu Island. Of these four species, H. kuishiensis sp. nov. contains two distinct mitochondrial lineages, but this split is not reflected in differentiation of allozyme (nuclear genome) markers. These species are morphologically similar to each other but can be differentiated by several characteristics, especially in combination of dorsal coloration, the number of vomerine, upper, and lower jaw teeth, and depth of vomerine teeth series. In coloration, H. guttatus sp. nov. is brown or dark brown mostly with tiny white to brownish white marking, while H. tsurugiensis sp. nov. is dark brown with bright yellow continuous markings. Hynobius kuishiensis sp. nov. is reddish purple or dark brown with small to continuous brownish white markings, in contrast to reddish purple or dark brown with small to large brownish white markings in H. stejnegeri.

Mi-sook Min - One of the best experts on this subject based on the ideXlab platform.

  • disentangling the impacts of speciation sympatry and the island effect on the morphology of seven Hynobius sp salamanders
    Open Access Journal, 2021
    Co-Authors: Amael Borzee, Mi-sook Min
    Abstract:

    Closely related individuals from different areas can see their morphologies change based on differences between clades, but also ecological variables such as the island effect or sympatry. This is the case of salamanders, which have adapted to a broad range of ecological niches, ranging from underground dwellers in xeric landscape to tropical arboreal habitats. On the Korean Peninsula, salamanders from the Hynobius clade are widespread on the mainland and islands, with several partially sympatric clades and candidate species. Currently, seven lineages have been identified based on mtDNA, four of them matching named species and three others for which the species status remains untested. While the morphology of Korean Hynobius is known to be variable between genetically segregated clades, we hypothesise that (1) the candidate species are morphologically different, and that (2) the island effect and (3) the sympatric status have significant impacts on the morphology of individuals within the genus. Here we measured 329 Hynobius salamanders from all seven clades, in areas of sympatry and allopatry, and on islands and on the mainland (Graphical Abstract A). We determined that the island effect had a significant impact on the morphology of the genus, with mainland individuals generally displaying a broader range of morphology than islandic individuals (Graphical Abstract B). We also determined that sympatry had an impact on morphology, with the sizes of individuals from clades in sympatric areas diverging from each other (Graphical Abstract C). Finally, we demonstrated that all seven clades have significantly different morphologies, and we described the three candidate species that had already been isolated based on mtDNA and microsatellite data: Hynobius notialis sp. nov., Hynobius geojeensis sp. nov. and Hynobius perplicatus sp. nov. We conclude that looking at morphology alone would be misleading about the true diversity of Hynobius species, and species in general, because of the island and patry effects.

  • genetic and phylogenetic structure of Hynobius quelpaertensis an endangered endemic salamander species on the korean peninsula
    Genes & Genomics, 2020
    Co-Authors: Ho Young Suk, Hae-jun Baek, Hang Lee, Hangyu Bae, Dongyoung Kim, Hari Won, Changhoon Lee, Dong Youn Kim, Jaeyoung Song, Mi-sook Min
    Abstract:

    The Korean Peninsula is a small but unique area showing great endemic Hynobius diversity with H. quelpaertensis, H. yangi, H. unisacculus and three species candidates (HC1, HC3 and HC4). H. quelpaertensis is distributed in the southern part and in Jeju Island, while the remaining species have extremely narrow distributions. To examine the genetic structure of H. quelpaertensis and the phylogenetic placement in Hynobius. Three mitochondrial and six microsatellite loci were genotyped for 204 Hynobius quelpaertensis, three H. leechii, three H. yangi, three HC1, two H. unisacculus, three HC3, three HC4 and ten Japanses H. lichenatus. A high level of mitochondrial diversity was found in H. quelpaertensis. Our mitochondrial data showed evidence of a historical link between inland and Jeju Island despite the signature of founder effect likely experienced by the early island populations. However, our microsatellite analysis showed the fairly clear signature of isolation history between in- and island populations. Upon phylogenetic analysis, H. quelpaertensis, H. unisacculus and HC1 formed a cluster, whereas H. yangi belonged to a separate cluster. HC3 and HC4 were clustered with either H. quelpaertensis or H. yangi depending on the locus used. Our results show at least partially the historical imprints engraved by dispersal of Korean endemic Hynobius during Pleistocene, potentially providing a fundamental basis in determining the conservation units and finding management strategies for these species.

  • the complete mitochondrial genome information of Hynobius unisacculus amphibia caudata hynobiidae and the phylogenetic implication
    Mitochondrial DNA Part B, 2019
    Co-Authors: Ho Young Suk, Dongyoung Kim, Sunho Cha, Mi-sook Min
    Abstract:

    Hynobius unisacculus is a hynobiid salamander species found only in a limited area at the southernmost part of the Korean Peninsula. Here, we characterized the complete mitochondrial genome of this...

  • Mitochondrial DNA Data Unveil Highly Divergent Populations within the Genus Hynobius
    2016
    Co-Authors: Hae-jun Baek, Mu-yeong Lee, Hang Lee, Mi-sook Min
    Abstract:

    Korean salamanders of the genus Hynobius are currently classified into 3 species, H. leechii, H. quelpaertensis, and H. yangi. To investigate the phylogenetic relationship of these species, we analyzed the partial sequence of mito-chondrial cytochrome b gene (907 bp) of 197 specimens from 43 regions in South Korea. Of these specimens, 93 were additionally examined with 12S rRNA (799 bp). Based on the partial sequence of the mitochondrial cytochrome b gene and 12S rRNA, 89 and 36 haplotypes were defined, respectively, consisting of six subclades (H. leechii, H. quelpaertensis, H. yangi, HC1, HC2, and HC3). Among these subclades, the three subclades (HC1, HC2, and HC3) were clearly separated from the 3 previously reported spe-cies in the genus Hynobius. Pairwise sequence divergence between the six subclades ranged from 6.3 to 11.2 % in cytochrome b gene and 2.0 to 4.3 % in 12S rRNA. These results indicate there may be more divergent populations than the three currently described. Moreover, the estima-tion of divergence time revealed that the Hynobius species in South Korea diverged during the Miocene epoch, ap-proximately 9- 5 MYA. In addition, we confirmed the distri-bution of the three known species (H. leechii, H. quel-paertensis, and H. yangi) and determined the distributions of new, distinct groups (or subclades; HC1, HC1, and HC3). To more accurately establish the taxonomic status and population structure, further genetic, morphological, and ecological studies will be needed

  • a new species of salamander of the genus Hynobius amphibia caudata hynobiidae from south korea
    Zootaxa, 2016
    Co-Authors: Mi-sook Min, Hae-jun Baek, Min Ho Chang, Jaeyoung Song, Nikolay A Poyarkov
    Abstract:

    We describe a new species of lentic-breeding Hynobius salamander from the Naro Islands, near the village of Bongrae-myeon, Goheung-gun, Jeollanam-do, South Korea, on the basis of results of morphological, ecological and genetic analyses. Hynobius unisacculus sp. nov. is distinguished from its congeners by a combination of the following morphological attributes: (1) comparatively small size (adult SVL up to 61 mm; range 38.3–60.3 mm in males and 37.5–59.9 mm in females); (2) relatively slender short limbs; tips of fore- and hindlimbs adpressed on body never meeting, but separated by a large gap (gap of -3.0 to -1.5 costal folds in males and -3.5 to -1.5 in females); (3) comparatively short tail (TL/SVL ratio in adult males varying from 0.54–0.98, in adult females from 0.55 to 0.89), tail flattened and with a low dorsal fin extending to the posterior one-third of tail length; (4) usually 11 (occasionally 12) costal grooves; (5) in adults, dark brown dorsum with indistinct bronze or dark copper spots, lighter greyish-white or pinkish belly; (6) well developed fifth toe; (7) comparatively shallow vomerine tooth series with 13–23 vomerine teeth; (8) small, pigmented ova, located in one, occasionally two, strings in a small, curved egg sac with folded envelope, lacking distinct mucous stalks or whiptail-like structures on both ends. The molecular differentiation among Korean Hynobius is high; Hynobius unisacculus sp. nov. is genetically highly divergent from the morphologically similar H. leechii , H. yangi and H. quelpaertensis : pairwise distances are 9.7%, 9.1% and 8.0% of sequence divergence at the COI mtDNA gene respectively, and 10.9%, 10.9% and 9.4% of sequence divergence at the cyt b mtDNA gene, respectively. At present, the new species is known from coastal areas and offshore islands in southeastern part of Jeollanam-do in South Korea. We suggest the species should be considered as Vulnerable (Vu2a) in accordance with IUCN’s Red List categories. Our study supports the presence of undiagnosed taxonomic diversity among Korean Hynobius .

Shingo Tanabe - One of the best experts on this subject based on the ideXlab platform.

  • wide distribution but low differentiation phylogenetic relationships and phylogeography of Hynobius nigrescens amphibia caudata
    Zoological Science, 2020
    Co-Authors: Masafumi Matsui, Gen Aoki, Shingo Tanabe, Natsuhiko Yoshikawa, Koji Sasamori, Masamichi Matsui, Yasuchika Misawa, Kanto Nishikawa
    Abstract:

    We surveyed the genetic structure of Hynobius nigrescens 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 H. nigrescens. Complete 1141 bp sequences of the mitochondrial cytochrome b gene were studied for 134 adult and larval individuals collected from 62 localities, encompassing the known range of the species. Hynobius nigrescens proved to be monophyletic, including two major clades (Clade II from southwestern Hokuriku and Clade I from all other localities). The latter clade comprises four well-supported and geographically structured subclades, which show genetic distances smaller than those seen in the widely sympatric species Hynobius lichenatus. Results of population statistical analyses indicated that Clade II of the westernmost range of H. nigrescens seems to have maintained a constant population size, while Clade I from most of the northeastern species range shows a tendency of recent population expansion, which is evident in Subclades I-A from the northernmost range and I-B from southern Tohoku to northern Kanto and eastern Chubu. In contrast, Subclades I-C from northeastern Chubu and Sado Is. and I-D from northwestern Chubu to Hokuriku seem to have been relatively stable in population size. Hynobius nigrescens differs greatly from other salamander species from northeastern Japan in its much more recent periods of genetic differentiation and its pattern thereof, and is suggested to be a young faunal element in this region.

  • a revision of Hynobius stejnegeri a lotic breeding salamander from western japan with a description of three new species amphibia caudata hynobiidae
    Zootaxa, 2019
    Co-Authors: Atsushi Tominaga, Shingo Tanabe, Masafumi Matsui, Kanto Nishikawa
    Abstract:

    A lotic-breeding salamander Hynobius stejnegeri, formerly called H. yatsui, from western Japan is revised based on genetic and morphological evidence, and three species are described: H. guttatus sp. nov. from Chubu-Kinki districts of Honshu Island, H. tsurugiensis sp. nov. from east highland of Shikoku Island, and H. kuishiensis sp. nov. from other parts of Shikoku Island. Thus, H. stejnegeri sensu stricto is restricted to Kyushu Island. Of these four species, H. kuishiensis sp. nov. contains two distinct mitochondrial lineages, but this split is not reflected in differentiation of allozyme (nuclear genome) markers. These species are morphologically similar to each other but can be differentiated by several characteristics, especially in combination of dorsal coloration, the number of vomerine, upper, and lower jaw teeth, and depth of vomerine teeth series. In coloration, H. guttatus sp. nov. is brown or dark brown mostly with tiny white to brownish white marking, while H. tsurugiensis sp. nov. is dark brown with bright yellow continuous markings. Hynobius kuishiensis sp. nov. is reddish purple or dark brown with small to continuous brownish white markings, in contrast to reddish purple or dark brown with small to large brownish white markings in H. stejnegeri.

  • systematics of the widely distributed japanese clouded salamander Hynobius nebulosus amphibia caudata hynobiidae and its closest relatives
    Current Herpetology, 2019
    Co-Authors: Masafumi Matsui, Kanto Nishikawa, Gen Aoki, Shingo Tanabe, Natsuhiko Yoshikawa, Yasuchika Misawa, Hiroshi Okawa, Koshiro Eto, Atsushi Tominaga
    Abstract:

    The abundant clouded salamander from western Japan, Hynobius nebulosus, has long been considered a single widespread species, although some authors have suggested the inclusion of several cryptic species. This led to a molecular and morphological analysis of populations from all parts of the known range. Phylogenetic relationships were inferred from complete sequences of the mitochondrial cytochrome b gene, and nuclear genome differentiations were estimated by multiplexed inter simple sequence repeat genotyping by sequencing (MIG-seq). The results suggest that H. nebulosus hitherto recognized consists of at least nine species. We applied existing names to two of them, H. nebulosus (Temminck et Schlegel) and H. vandenburghi Dunn, and described seven others as new species.

  • systematic relationships of Hynobius okiensis among japanese salamanders amphibia caudata
    Zoological Science, 2007
    Co-Authors: Masafumi Matsui, Kanto Nishikawa, Yasuchika Misawa, Shingo Tanabe
    Abstract:

    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. nebulosus group (H. nebulosus and H. dunni) with the same chromosome number than to the lotic-breeding H. naevius group (H. naevius and H. kimurae) and H. boulengeri with 58 chromosomes. Chromosome number reduction from 58 to 56, possibly accompanied with a change in breeding environment from streams to still waters, is estimated to have first occurred in the nebulosus group of Hynobius. A reversal only in breeding habits then seems to have followed in steep, montane environments of the small island of Dogo, resulting in the speciation of H. okiensis.

  • phylogenetic relationships and phylogeography of Hynobius tokyoensis amphibia caudata using complete sequences of cytochrome b and control region genes of mitochondrial dna
    Molecular Phylogenetics and Evolution, 2007
    Co-Authors: Masafumi Matsui, Atsushi Tominaga, Yasuchika Misawa, Terutake Hayashi, Shingo Tanabe
    Abstract:

    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. Monophyly of H. tokyoensis was supported in all trees analyzed, and two clades consistently emerged: clade A from northeastern Kanto (Ibaraki) to southern Tohoku (Fukushima), and clade B from the remaining area south of northern Kanto (Tochigi). These two clades are estimated to have an old history of divergence during the late Pliocene, when the present-day Kanto Plain was under the sea. Within clade B, three haplotypes groups (I-III) are hypothesized to have diverged more recently, i.e., between the early and mid-Pleistocene, probably in relation to glacial events. The ancestral groups I and II were separated at the present-day western Kanto and Boso Peninsula areas, respectively, and subsequently, group II invaded northward to the present-day northern Kanto area and gave rise to group III. Populations of the Miura Peninsula are thought to have multiple origins, one directly from Boso and another from a more recent southward invasion from the northern Kanto area. Cytochrome b appears to have evolved more quickly than CR genes in H. tokyoensis, and thus will be more useful for phylogenetic analyses and formulating conservation measures.

Hae-jun Baek - One of the best experts on this subject based on the ideXlab platform.

  • genetic and phylogenetic structure of Hynobius quelpaertensis an endangered endemic salamander species on the korean peninsula
    Genes & Genomics, 2020
    Co-Authors: Ho Young Suk, Hae-jun Baek, Hang Lee, Hangyu Bae, Dongyoung Kim, Hari Won, Changhoon Lee, Dong Youn Kim, Jaeyoung Song, Mi-sook Min
    Abstract:

    The Korean Peninsula is a small but unique area showing great endemic Hynobius diversity with H. quelpaertensis, H. yangi, H. unisacculus and three species candidates (HC1, HC3 and HC4). H. quelpaertensis is distributed in the southern part and in Jeju Island, while the remaining species have extremely narrow distributions. To examine the genetic structure of H. quelpaertensis and the phylogenetic placement in Hynobius. Three mitochondrial and six microsatellite loci were genotyped for 204 Hynobius quelpaertensis, three H. leechii, three H. yangi, three HC1, two H. unisacculus, three HC3, three HC4 and ten Japanses H. lichenatus. A high level of mitochondrial diversity was found in H. quelpaertensis. Our mitochondrial data showed evidence of a historical link between inland and Jeju Island despite the signature of founder effect likely experienced by the early island populations. However, our microsatellite analysis showed the fairly clear signature of isolation history between in- and island populations. Upon phylogenetic analysis, H. quelpaertensis, H. unisacculus and HC1 formed a cluster, whereas H. yangi belonged to a separate cluster. HC3 and HC4 were clustered with either H. quelpaertensis or H. yangi depending on the locus used. Our results show at least partially the historical imprints engraved by dispersal of Korean endemic Hynobius during Pleistocene, potentially providing a fundamental basis in determining the conservation units and finding management strategies for these species.

  • Mitochondrial DNA Data Unveil Highly Divergent Populations within the Genus Hynobius
    2016
    Co-Authors: Hae-jun Baek, Mu-yeong Lee, Hang Lee, Mi-sook Min
    Abstract:

    Korean salamanders of the genus Hynobius are currently classified into 3 species, H. leechii, H. quelpaertensis, and H. yangi. To investigate the phylogenetic relationship of these species, we analyzed the partial sequence of mito-chondrial cytochrome b gene (907 bp) of 197 specimens from 43 regions in South Korea. Of these specimens, 93 were additionally examined with 12S rRNA (799 bp). Based on the partial sequence of the mitochondrial cytochrome b gene and 12S rRNA, 89 and 36 haplotypes were defined, respectively, consisting of six subclades (H. leechii, H. quelpaertensis, H. yangi, HC1, HC2, and HC3). Among these subclades, the three subclades (HC1, HC2, and HC3) were clearly separated from the 3 previously reported spe-cies in the genus Hynobius. Pairwise sequence divergence between the six subclades ranged from 6.3 to 11.2 % in cytochrome b gene and 2.0 to 4.3 % in 12S rRNA. These results indicate there may be more divergent populations than the three currently described. Moreover, the estima-tion of divergence time revealed that the Hynobius species in South Korea diverged during the Miocene epoch, ap-proximately 9- 5 MYA. In addition, we confirmed the distri-bution of the three known species (H. leechii, H. quel-paertensis, and H. yangi) and determined the distributions of new, distinct groups (or subclades; HC1, HC1, and HC3). To more accurately establish the taxonomic status and population structure, further genetic, morphological, and ecological studies will be needed

  • a new species of salamander of the genus Hynobius amphibia caudata hynobiidae from south korea
    Zootaxa, 2016
    Co-Authors: Mi-sook Min, Hae-jun Baek, Min Ho Chang, Jaeyoung Song, Nikolay A Poyarkov
    Abstract:

    We describe a new species of lentic-breeding Hynobius salamander from the Naro Islands, near the village of Bongrae-myeon, Goheung-gun, Jeollanam-do, South Korea, on the basis of results of morphological, ecological and genetic analyses. Hynobius unisacculus sp. nov. is distinguished from its congeners by a combination of the following morphological attributes: (1) comparatively small size (adult SVL up to 61 mm; range 38.3–60.3 mm in males and 37.5–59.9 mm in females); (2) relatively slender short limbs; tips of fore- and hindlimbs adpressed on body never meeting, but separated by a large gap (gap of -3.0 to -1.5 costal folds in males and -3.5 to -1.5 in females); (3) comparatively short tail (TL/SVL ratio in adult males varying from 0.54–0.98, in adult females from 0.55 to 0.89), tail flattened and with a low dorsal fin extending to the posterior one-third of tail length; (4) usually 11 (occasionally 12) costal grooves; (5) in adults, dark brown dorsum with indistinct bronze or dark copper spots, lighter greyish-white or pinkish belly; (6) well developed fifth toe; (7) comparatively shallow vomerine tooth series with 13–23 vomerine teeth; (8) small, pigmented ova, located in one, occasionally two, strings in a small, curved egg sac with folded envelope, lacking distinct mucous stalks or whiptail-like structures on both ends. The molecular differentiation among Korean Hynobius is high; Hynobius unisacculus sp. nov. is genetically highly divergent from the morphologically similar H. leechii , H. yangi and H. quelpaertensis : pairwise distances are 9.7%, 9.1% and 8.0% of sequence divergence at the COI mtDNA gene respectively, and 10.9%, 10.9% and 9.4% of sequence divergence at the cyt b mtDNA gene, respectively. At present, the new species is known from coastal areas and offshore islands in southeastern part of Jeollanam-do in South Korea. We suggest the species should be considered as Vulnerable (Vu2a) in accordance with IUCN’s Red List categories. Our study supports the presence of undiagnosed taxonomic diversity among Korean Hynobius .

  • Mitochondrial DNA data unveil highly divergent populations within the genus Hynobius (Caudata: Hynobiidae) in South Korea
    Molecules and Cells, 2011
    Co-Authors: Hae-jun Baek, Mu-yeong Lee, Hang Lee, Mi-sook Min
    Abstract:

    Korean salamanders of the genus Hynobius are currently classified into 3 species, H. leechii, H. quelpaertensis , and H. yangi . To investigate the phylogenetic relationship of these species, we analyzed the partial sequence of mitochondrial cytochrome b gene (907 bp) of 197 specimens from 43 regions in South Korea. Of these specimens, 93 were additionally examined with 12S rRNA (799 bp). Based on the partial sequence of the mitochondrial cytochrome b gene and 12S rRNA, 89 and 36 haplotypes were defined, respectively, consisting of six subclades ( H. leechii, H. quelpaertensis, H. yangi , HC1, HC2, and HC3). Among these subclades, the three subclades (HC1, HC2, and HC3) were clearly separated from the 3 previously reported species in the genus Hynobius . Pairwise sequence divergence between the six subclades ranged from 6.3 to 11.2% in cytochrome b gene and 2.0 to 4.3% in 12S rRNA. These results indicate there may be more divergent populations than the three currently described. Moreover, the estimation of divergence time revealed that the Hynobius species in South Korea diverged during the Miocene epoch, approximately 9 — 5 MYA. In addition, we confirmed the distribution of the three known species ( H. leechii, H. quelpaertensis , and H. yangi ) and determined the distributions of new, distinct groups (or subclades; HC1, HC1, and HC3). To more accurately establish the taxonomic status and population structure, further genetic, morphological, and ecological studies will be needed.

  • age structure and growth rates of two korean salamander species Hynobius yangi and Hynobius quelpaertensis from field populations
    Animal Cells and Systems, 2010
    Co-Authors: Junghyun Lee, Hae-jun Baek, Hang Lee, Mi-sook Min, Taeho Kim, Daesik Park
    Abstract:

    We studied and compared the age structure, body size, and growth rates of field populations of two Korean salamander species (Hynobius yangi and Hynobius quelpaertensis) to elucidate important aspects of basic population dynamics of these two endemic Hynobius species. In both populations, females were sexually mature at three years of age, while H. yangi and H. quelpaertensis males matured at two and three years of age, respectively. Both males and females of H. yangi and H. quelpaertensis attained a maximum age of 11 years and 10 years, respectively. In both species, the snout-vent length (SVL) and body weight (BW) of the females were greater than those of the males. The SVL, BW, and asymptotic SVL of both male and female H. yangi were smaller than those of H. quelpaertensis. The adult growth rates after sexual maturation of male and female H. yangi were lower than those of H. quelpaertensis, possibly resulting in the smaller body size of the former, although overall growth coefficients were not significantly different between the two species. We also compared the age structure and growth rates of three Korean and three Japanese species of Hynobius.