著者
Sasaki Motoki Endo Hideki Yamamoto Masako ARISHIMA Kazuyoshi HAYASHI Yoshihiro
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.25, no.1, pp.27-34, 2000-06-01
被引用文献数
3 7

The musculature and functional anatomy of the head and skull of a tiger <i>Panthera tigris</i> were, examined and compared with those of various other felid species. The <i>Musculus masseter</i> is divided into three layers. The superficial layer of which is well-developed and further sub-divided into lateral and medial components. The ventro-caudal fleshy portion of the lateral component originates behind the last upper molar, where it is attached by a strong tendon to the tubercle <i>tuber maxillae</i>. The medial component, which runs dorso-ventrally, has a particularly well-developed fleshy portion. The present anatomical study suggests that in the tiger, large masseteric forces are produced in both ventro-rostral and ventro-dorsal directions. In the tiger, a process is present on the tubercle of the maxilla from which the strong tendon originates. This process is also apparent in the leopard <i>Panthera pardus</i>, the jaguar <i>P. onca</i> and the puma <i>Felis concolor</i>. It is not found, however, in either the domestic cat <i>F. catus</i> or the Iriomote wild cat <i>F. iriomotensis</i>. Comparisons between the skulls of various species of felidae indicate that whereas the puma, the leopard and the jaguar each possess the strong tendon, which bundles the ventro-caudal fleshy portion of the lateral component, the domestic cat and the Iriomote wild cat only possess weak tendons attaching to this component.
著者
Kawada Shin-ichiro Shinohara Akio Yasuda Masatoshi ODA Sen-ichi LIAT Lim Boo
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.30, no.2, pp.109-115, 2005-12-01
被引用文献数
4 5

We report the first karyological description of a southeast Asian mole, the Malaysian mole (<i>Euroscaptor micrura malayana</i>). The karyotype of the Malaysian mole includes 36 chromosomes, which consist of 18 biarmed and 16 acrocentric autosomes and the sex pair. The sex chromosomes are a small meta-submetacentric X chromosome and a minute dot-like Y chromosome, although the latter is somewhat larger than that of some talpid allies. Autosomal complements include one pair of NOR-bearing chromosomes. A comparative G-banding analysis with the Japanese congener <i>E. mizura</i> showed that these two species share high G-banding homology, and their differences on two pairs of chromosomes are explained by a single reciprocal translocation. The karyological similarity of these distant geographic species is discussed in a systematic and evolutionary context, based on comparisons to other species distributed between them.<br>
著者
Shinohara Akio Campbell Kevin L. Suzuki Hitoshi
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.30, pp.S19-S24, 2005-12-01
被引用文献数
4 11

Japanese talpid moles exhibit a remarkable degree of species richness and geographic complexity, and as such, have attracted much research interest by morphologists, cytogeneticists, and molecular phylogeneticists. However, a consensus hypothesis pertaining to the evolutionary history and biogeography of this group remains elusive. Recent phylogenetic studies utilizing nucleotide sequences have provided reasonably consistent branching patterns for Japanese talpids, but have generally suffered from a lack of closely related South-East Asian species for sound biogeographic interpretations. As an initial step in achieving this goal, we constructed phylogenetic trees using publicly accessible mitochondrial and nuclear sequences from seven Japanese taxa, and those of related insular and continental species for which nucleotide data is available. The resultant trees support the view that four lineages (<i>Euroscaptor mizura</i>, <i>Mogera tokuade</i> species group [<i>M. tokudae</i> and <i>M. etigo</i>], <i>M. imaizumii</i>, and <i>M. wogura</i>) migrated separately, and in this order, from the continental Asian mainland to Japan. The close relationship of <i>M. tokudae</i> and <i>M. etigo</i> suggests these lineages diverged recently through a vicariant event between Sado Island and Echigo plain. The origin of the two endemic lineages of Japanese shrew-moles, <i>Urotrichus talpoides </i>and <i>Dymecodon pilirostris</i>, remains ambiguous. Further analyses on intra-species diversity are necessary to fully solve the evolutionary histories of Japanese moles and shrew-moles.<br>
著者
Kaneko Yukibumi
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.26, no.1, pp.17-33, 2001-06-01
被引用文献数
3 5

Thirty-eight museum specimens of the Ryukyu spiny rat, belonging to the genus <i>Tokudaia</i> Kuroda, 1943 (Rodentia, Muridae), from the islands of Amami Oshima and Okinawa, in the Ryukyu Islands (=the Nansei Islands), southern Japan, were examined and measured. Each specimen was classified into one of five age groups (I-V) determined by the wear of the three upper molars. The spiny rat of Okinawa has on average within age groups III and IV a statistically longer and wider skull and a longer molar row than that of Amami Oshima. However, neither the posterior nor the central parts of the skull length and width differ between the two islands. Against the same size of head and body length (H&BL) or incisor - the third upper molar length (I-M3), the spiny rat of Okinawa has longer I-M3 or narrower zygomatic arches than the spiny rat of Amami Oshima. The Okinawan spiny rat has a wider first upper molar (wM1≥1.9 mm), whereas that of Amami Oshima is wM1≤1.8 mm. The Okinawan spiny rat has the palatine foramen of the skull situated more posteriorly than that of Amami Oshima. These findings indicate conclusively that the spiny rat populations on the two islands of Amami Oshima and Okinawa have distinctly different morphological characteristics, in addition to having different karyotypes, and as such they should be regarded as distinct species. The spiny rat of Amami Oshima should be named as <i>Tokudaia osimensis</i> (Abe, 1933) while that of Okinawa should be known as <i>Tokudaia muenninki</i> (Johnson, 1946).
著者
Nakanishi Nozomi Okamura Maki Watanabe Shinichi IZAWA Masako DOI Teruo
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.30, no.1, pp.1-10, 2005-06-01
被引用文献数
2 9

The seasonal variation in home range size of one male and one female Iriomote Cat <i>Prionailurus bengalensis iriomotensis</i> was studied by radio-tracking and automatic photography on Iriomote Island, Japan. The study was conducted in the Shirahama area located in the western part of the island. Shirahama provides a small area of suitable lowland habitat (<50 m a.s.l.) for the Iriomote Cat. Two individuals, one male and one female, were confirmed to be resident in this area. The periodical home range size of the male was 1.24 ± 0.41 km<sup>2</sup> and that of the female was 1.30 ± 0.54 km<sup>2</sup> throughout the year, with no significant difference between them. We compared the results of these observations with those from another area of suitable habitat in Funaura and discussed what factors may affect male home range size. The home range of the male cat in Shirahama was found to be only half the size of that of males in Funaura, though it showed similar seasonal fluctuation. The home ranges of females were similar in the two areas. Our results provide empirical confirmation of the influence of the number and distribution of females on male home range size in a solitary felid.<br>
著者
Okamura Maki Doi Teruo Sakaguchi Noriaki IZAWA Masako
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.25, no.2, pp.75-85, 2000-12-01
被引用文献数
5 6

The Iriomote cat, <i>Felis iriomotensis</i>, is a small felid endemic to Iriomote Island, Okinawa, Japan. Little is known of its breeding ecology in either captivity or the wild. In this study we investigated the reproductive cycle from observations of the frequency of male urine marking, reproductive conditions and behaviors of females with young in the field, and with reference to previous reports related to breeding. Breeding of female Iriomote cats may not be seasonally restricted, although a mating peak was recognized between February and April. Females delivered litters between April and June, and maternal care continued until kittens reached four to 4.5 months of age.
著者
Hashimoto Takuma Abe Manabu
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.26, no.1, pp.35-44, 2001-06-01
被引用文献数
2 3

Two species of moles, <i>Mogera tokudae</i> and <i>M. imaizumii</i>, are parapatrically distributed in the Echigo Plain in the northern part of Niigata Prefecture, Japan. The two species are morphologically similar, except for the larger body size of <i>M. tokudae</i>. To clarify whether interspecific competition affects body size and reproductive traits of these moles, we compared these characteristics in syntopic populations with those in allopatric populations for both species in the Echigo Plain. <i>Mogera tokudae</i> exhibited little body size difference between allopatric and syntopic populations, while body size of <i>M. imaizumii</i> in syntopic populations was significantly smaller than in allopatric populations. Although litter sizes of both species were almost the same, reproductive schedules were different. Pregnant <i>M. tokudae</i> were captured mostly in late April, whereas <i>M. imaizumii</i> had a longer period of reproduction from March to October; some individuals bred twice a year. The relatively small body size and the longer breeding period observed in <i>M. imaizumii</i> of the Echigo Plain may be tactics for increasing reproductive success under severe interspecific competition from <i>M. tokudae</i>.
著者
Suzuki Hitoshi Iwasa Masahiro A. Ishii Nobuo NAGAOKA Hiroko TSUCHIYA Kimiyuki
出版者
日本哺乳類学会
雑誌
Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
巻号頁・発行日
vol.24, no.1, pp.43-50, 1999-06-01
被引用文献数
6 11

We examined the geographic variation of <i>Tokudaia osimensis</i> through the analysis of mitochondria1 cytochrome <i>b</i> (cyt <i>b</i>) gene sequences and the restriction fragment length polymorphism (RFLP) in the nuclear ribosomal RNA gene (rDNA), using samples collected from Tokuno-shima and Amami-oshima in the Ryukyu Islands. The two populations show intrinsic karyological variation (Tokuno-shima, 2n=45; Amami-oshima, 2n=25). Sequences of the cyt <i>b</i> gene differed considerably between the two island populations. The extent of the sequence divergence among 1,140 bp of the gene was calculated to be 0.088 using the Kimura two parameter method, and was comparable to those between related species of rodents such as within genus <i>Mus</i> or <i>Rattus</i>. The extent of the differentiation in the rDNA-RFLP was also high. Three out of 22 restriction site variants were found to be fixed in the nuclear rDNA arrays of hundreds of copies in either one of the two island populations. These intensive inter-populational differences indicate that the two island populations may have been isolated for a considerable period of evolutionary time, probably several millions of years, despite there having been several opportunities for renewed genetic contact during the Pleistocene ice ages. Our data strongly suggest that the current taxonomic status of the populations of the two islands, Amami-oshima and Tokuno-shima, which regards them conspecific, should be reviewed.