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Three nominal species of Ateleopodidae; Ateleopus japonicus Bleeker 1853, A. purpureus Tanaka 1915, and A. tanabensis Tanaka 1918, were taxonomically reviewed. Examination of many specimens, including the holotype of A. tanabensis and the newly designated lectotype of A. japonicus and A. schlegelii, revealed that their morphological differences can be explained by intraspecific variation and ontogenetic change within one species. Mitochondrial DNA analyses supported the results of the morphological study. Thus, A. purpureus and A. tanabensis are considered junior synonyms of A. japonicus. We have concluded after an examination of the relevant publications that Ateleopus schlegelii van der Hoeven 1855 is also a junior synonym of A. japonicus.

The “striata complex,” a group of spined loaches included in the genus Cobitis and characterized by a striped coloration pattern on the lateral midline, is distributed in rivers in northeastern Asia to western Japan. The complex comprises 2 continental species (Cobitis tetralineata and Cobitis lutheri) and 3 Japanese races of species rank (large race, middle race, and small race), the small race further comprising 6 local forms of subspecific rank (Tokai form, Biwa form, Yodo form, Sanyo form, San-in form, and Kyushu form). Previous karyological studies have revealed that the large race is an allotetraploid, the others being diploid. In this study, mitochondrial (mt) DNA analyses were conducted for 30 diploid populations of the Cobitis striata complex from Japan and Korea to examine: (1) their phylogenetic relationships and the position of the complex among the major lineages of Cobitis; and (2) the genetic relationships among the Japanese and Korean populations. The results, based on cytochrome b sequences (724 base pairs) analyzed with those of the main lineage of European and Japanese Cobitis, indicated that the striata complex should be considered as a monophyletic group, which evolved in northeastern Asia. Initially considered as a subspecies of Cobitis taenia, widely distributed from Europe to Asia, the striata complex does not have a sister-relationship with the former. Although the Korean species C. tetralineata was formerly believed to be closely related to the middle race in Japan, and a second continental species, C. lutheri, closely related to the Kyushu or San-in forms of the small race in Japan, the trees resulting from the present study revealed that the two Korean species were clustered with each other and separated from all Japanese races.

1988 年にオオクチバスフロリダ半島産亜種が放流された池原貯水池では，1996, 1997 年の遺伝学的調査においてフロリダ半島産亜種由来のミトコンドリア DNA（mtDNA）をもつ個体の割合は 56.8% であった。今回（2003 年）再調査を行った結果，本亜種由来の mtDNA をもつ個体は全体の 86.7% となり，前回調査より有意な増加がみとめられた。また，近畿地方の池原貯水池とは別水系の湖沼（津風呂湖，宝ヶ池，深泥池）からも本亜種由来の mtDNA をもつ個体が検出された。

The Japanese spined loach Cobitis biwae includes the tetraploid form, which has 96 chromosomes, as well as the diploid form, which has 48 chromosomes. In the present study, we analyzed the mitochondrial DNA (mtDNA) to examine the genetic relationships among 82 populations of diploid–tetraploid complexes of C. biwae. Restriction fragment length polymorphism (RFLP) analysis of the ND1 region on 202 individuals revealed that C. biwae contains three genetically divergent major groups corresponding to geographical proximities (the Eastern, Western, and Kochi groups). Phylogenetic analyses (neighbor-joining, NJ and maximum-parsimony, MP) of a part of the cytochrome b gene sequence (748 bp) in 31 individuals supported the three major groups recognized by RFLP, and indicated considerable genetic differentiation between the Western group and the other two groups (average, 15.2%). The genetic relationship and distribution pattern of the three major groups hypothesized two major dispersions of C. biwae during the middle Miocene: first, the ancestor of the Eastern and Kochi groups had spread from the West through wide regions of present-day Honshu and Shikoku Islands, and following that period, the ancestor of the Western group with a different mtDNA composition, probably resulting from the mtDNA introgression from C. takatsuensis, moved into western Japan and pushed the former north eastward. All tetraploid form populations were included in the Western group and treated as a monophyletic cluster with low genetic divergence. It is notable that two diploid populations geographically adjacent to the tetraploid range were genetically closely related to the tetraploid forms. This result suggests that these diploid populations were directly related to the maternal origin of the tetraploid form.

Three nominal species of Ateleopodidae; Ateleopus japonicus Bleeker 1853, A. purpureus Tanaka 1915, and A. tanabensis Tanaka 1918, were taxonomically reviewed. Examination of many specimens, including the holotype of A. tanabensis and the newly designated lectotype of A. japonicus and A. schlegelii, revealed that their morphological differences can be explained by intraspecific variation and ontogenetic change within one species. Mitochondrial DNA analyses supported the results of the morphological study. Thus, A. purpureus and A. tanabensis are considered junior synonyms of A. japonicus. We have concluded after an examination of the relevant publications that Ateleopus schlegelii van der Hoeven 1855 is also a junior synonym of A. japonicus.