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The Eastern-Japanese common toad, Bufo japonicus formosus, is distributed from southern Hokkaido to Kinki district of northeastern Honshu, Japan. However, Hokkaido populations are suspected to be nonnative and derived from relatively recent artificial introduction from Honshu. To clarify the origin of Hokkaido populations, we analyzed sequence variations of the mitochondrial cytochrome b gene in the toads from Hokkaido and compared the sequence data from previous studies. We obtained ten haplotypes from six sites on Hokkaido. Samples from the sites located along Ishikari river system, Asahikawa, Ebetsu, and Ishikari cities, had six haplotypes. Only one haplotype was obtained in Sapporo city and it was genetically far from Ishikari river's ones. Hakodate and Muroran cities samples had one and two haplotypes, respectively. All ten haplotypes from Hokkaido were genetically identical or close to haplotype data from Kanto district or Shizuoka Prefecture, mid-eastern Honshu, far from Hokkaido. Therefore, the toad populations of Hokkaido were considered to be nonnative and multiple introductions from eastern Honshu to Hokkaido were implied. [ABSTRACT FROM AUTHOR]

In order to clarify whether the populations of Pelodiscus from the main islands of Japan are indigenous or artificially introduced, we constructed a mitochondrial phytogeny among samples from Japan and adjacent regions. The results strongly suggested the presence in Japan of various mitochondrial haplotypes that largely formed two divergent groups, one supposedly corresponding to P. sinensis (Wiegmann, 1834) sensu stricto and the other to P. maackii (Brandt, 1857). Haplotypes putatively associated with P maackii were unique to, and broadly prevailing in Japan. This may reflect indigenous nature of P. maackii in Japan, which would be more appropriately referred to as P. japonicus (Temminck and Schlegel, 1835). The others, putatively associated with P. sinensis, were fewer in Japan, and included those shared with individuals sold in a fish market of the continental China, suggesting the current Japanese P. sinensis to be exotic. [ABSTRACT FROM AUTHOR]

Reeves' pond turtle, Mauremys reevesii, is an aquatic geoemydid species that is broadly distributed in East Asia. Like many other Asian turtles, this species is facing an extinction crisis in most countries where it occurs. In Japan, however, this turtle commonly occurs in various freshwater habitats. Although the Japanese populations have generally been considered to be native, a few recent studies have yielded circumstantial evidence that suggested that they had originated from relatively recent artificial introductions from abroad. To evaluate the validity of such a view, we analyzed sequence variations of the mitochondrial cytochrome b gene and the control region in M. reevesii samples from various localities in Japan and adjacent countries. The results revealed the presence of 3 distinct genetic groups (groups A, B, and C) in the Japanese samples, of which groups A and B included haplotypes that were almost identical with some haplotypes from the Korean sample and the Chinese and Taiwanese samples, respectively. Sequences from M. reevesii shell products commercially traded in Taiwan included one that was almost identical to the group C sequence. The current Japanese populations of M. reevesii seem to have been derived from multiple artificial introductions from adjacent countries. This finding implies a need to be concerned about the effect of M. reevesii on the Japanese native wildlife, particularly on the Japanese endemic pond turtle, Mauremys japonica, with which M. reevesii is phylogenetically closely related and reportedly frequently hybridizes in the wild. However, the Japanese population may be useful as a genetically variable stock for conservation of this species, which is highly endangered in most of its range outside Japan. [ABSTRACT FROM AUTHOR]