title: Taxonomic relationship between two Gammarus species, G. nipponensis and G. sobaegensis (Amphipoda: Gammaridae), with description of a new species.
abstract: To assess the taxonomic relationship between G. nipponensis and G. sobaegensis, morphological features and molecular phylogenetic relationships using the nuclear 28S rRNA and the mitochondrial COI genes were examined. Detailed morphological observations revealed that G. nipponensis and G. sobaegensis were clearly distinguishable. In addition to the morphological differences, these two species were genetically diverged. In the course of this study, an undescribed species was found from Tsushima and Iki Islands and described here as G. mukudai. In the molecular phylogenetic analyses, monophyletic relationships of G. nipponensis, G. sobaegensis, and G. mukudai were shown but relationships among three species were unclear due to low statistical supports. Phylogeography of G. nipponensis, G. sobaegensis, and G. mukudai were discussed.
authors.affiliation: Department of Science Education, Graduate School of Education, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8524, Japan.; Email: tomikawa@hiroshima-u.ac.jp.
authors.forename: Ko
authors.initials: K
authors.lastname: Tomikawa
authors.affiliation: Faculty of Marine Technology, Chonnam National University, Yeosu, Jeonnam 550-749, Republic of Korea; Email: unknown.
authors.forename: Ho Young
authors.initials: HY
authors.lastname: Soh
authors.affiliation: Center for University-wide Education, School of Health and Social Services, Saitama Prefectural University, 820 San-Nomiya, Saitama 343-8540, Japan; Email: unknown.
authors.forename: Norio
authors.initials: N
authors.lastname: Kobayashi
authors.affiliation: Kobe University Research Center for Inland Seas, Kobe, Hyogo 657-8501, Japan; Email: unknown.
authors.forename: Aika
authors.initials: A
authors.lastname: Yamaguchi
mesh_terms: D033304:Amphipoda / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D009929:Organ Size; D010802:Phylogeny