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This report demonstrates the variable cardiac rhythm in two species of subterranean mole, the large Japanese mole (Mogera wogura) and the lesser Japanese mole (Mogera imaizumii). The phenomenon was revealed using X-ray videos of M. wogura and investigated in detail using electrocardiogram (ECG) traces recorded with implanted electrodes in this species and M. imaizumii. Cessation of heartbeat and extended R-R intervals were observed in the ECGs from both species during short bouts of rest in wakeful specimens of both species under normoxic conditions at room temperature. The mean durations of R-R intervals were 288.8 ± 3.3 ms for M. wogura and 191.9 ± 2.4 ms for M. imaizumii. The cardiac rhythm in both species became more unstable and R-R interval was prolonged by 153.5% ± 17.7 after injection of a sympathetic blocker (propranolol), whereas the application of a parasympathetic blocker (atropine) resulted in increasing stability and a reduced interval between R wave peaks (R-R) 64.2% ± 4.8. ECGs of two related soricomorphs, the fossorial Japanese shrew-mole (Urotrichus talpoides) and surface-dwelling Japanese white-toothed shrew (Crocidura dsinezumi) were also recorded and compared for comparison. The heartbeats of these species were relatively stable compared with those of the subterranean moles. Our results indicated clear differences in the physiological cardiac features between the examined members of the Soricomorpha.

I investigated geographic variation in the Japanese white-toothed shrewCrocidura dsinezumi (Temminck, 1842) (Insectivora, Soricidae) from the Japanese Archipelago and the northern part of the Ryukyu Archipelago. Univariate and multivariate analyses were conducted based on 11 cranial measurements from 14 sampling localities. Overall size variation seemed to follow clinal changes correlated with latitude and longitude of localities, such that northeastern populations were smaller than southwestern ones. The Hokkaido population and the Kuchinoerabujima population were larger than expected based on estimated values, likely due to changes reflecting environmental factors. In contrast, the Tanegashima population was smaller than its estimated value. The northern Ryukyu populations were divergent from the Kyushu population and from each other. Based on patterns of geographic variation, I suggest that all previously described subspecies ofC. dsinezumi are junior synonyms ofC. dsinezumi; and that the Kuchinoerabujima population and the Nakanoshima population likely represent un- described subspecies.

Molecular phylogeny of crocidurine shrews (Insectivora, Soricidae) in northeastern Asia was investigated to confirm the taxonomic status of unidentified specimens of Crocidura from Cheju Island, South Korea. Phylogenetic trees were constructed by neighbor-joining (NJ) and maximum likelihood (ML) methods, based on the mitochondrial cytochrome b gene sequences (402 base pairs) of 40 individuals of seven crocidurine species and three unidentified specimens from 31 localities mainly in northeastern Asia. Phylogenetic positions of the three unidentified specimens from Cheju Island were compared with those of Suncus murinus, C. attenuata, C. dsinezumi, C. lasiura, C. sibirica, C. suaveolens and C. watasei. Both in NJ and ML trees, the three unidentified specimens were included in the cluster of C. dsinezumi and obviously different from C. suaveolens on Cheju Island. Thus, the present investigation demonstrated that both of C. suaveolens and C. dsinezumi exist on Cheju Island.

Les caracteres externes, crâniens et dentaires d'un nouveau specimen d'une musaraigne rare et mal connue, Crocidura orii Kuroda, 1924 collectee dans l'ile d'Amamioshima, du groupe des iles Amami de l'Archipel des Ryukyu, Japon, ont ete examines. Une description complementaire de cette espece est presentee, et le statut taxonomique de orii est reevalue. Crocidura orii est comparee avec C. dsinezumi (Temminck, 1842), et les differences morphologiques entre elles sont determinees. La biogeographie de la faune des Ryukyus centrales au Japon, est discutee.

To assess the Zoogeographie and phylogenetic relationships of C. dsinezumi , its systematic position has been investigated through electrophoretic comparisons. These comparisons comprise typical Indomalayan and Palaearctic species, including C mssula , the supposed sister taxon of the Japanese white-toothed shrew. The range of measured genetic distances that separate dsinezumi from the other shrews (Nei's D = 0.232–0.406) is typical for interspecific comparisons among Crocidura taxa. Our results reinforce morphologic considerations that suggest C. dsinezumi be treated as a valid species. Phylogenetic relationships deduced from a cladistic treatment of allozyme data refute the possibility that the western Palaearctic C mssula is the sister taxon of C. dsinezumi . Zoogeographie interpretation of the genetic results indicates that the Southeast Asian representatives constitute a clade distinct from one that includes the Palaearctic species. However, C dsinezumi is difficult to assign to either clade due to many intermediate or plesiomorphic electrophoretic characters. Unlike the major karyologic and biochemical separation that divides Afrotropical and Palaearctic species, the subdivision between Palaearctic and Indomalayan Crocidura is not correlated with any trend in karyotypic evolution. It also is shown that the Eurasiatic species of Crocidura possessing 2n = 40 chromosomes (including C. dsinezumi ) do not represent a particular clade, but probably share a plesiomorphic character. Further analysis of other Indian or Asiatic species is needed to test whether the Palaearctic versus Indomalayan separation is due to real Zoogeographie barriers or whether it is the result of limited samples.