title: Systematic Relationships of Hynobius okiensis among Japanese Salamanders (Amphibia: Caudata).
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.
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan. fumi@zoo.zool.kyoto-u.ac.jp
authors.forename: Masafumi
authors.initials: M
authors.lastname: Matsui
authors.forename: Kanto
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Misawa
authors.forename: Shingo
authors.initials: S
authors.lastname: Tanabe
mesh_terms: D000818:Animals; D004592:Electrophoresis, Starch Gel / Q000662:veterinary; D004798:Enzymes / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation; D007564:Japan; D007814:Larva / Q000201:enzymology; D010802:Phylogeny; D014562:Caudata / Q000145:classification* / Q000235:genetics / Q000502:physiology