Differential geographic patterns of mitochondrial DNA variation in two sympatric species of Japanese wood mice, Apodemus speciosus and A. argenteus

We examined the gene sequences of mitochondrial cytochrome b (cyt b) in two Japanese wood mouse species, Apodemus speciosus (n = 89) and A. argenteus (n = 46), which are distributed on the four main islands of Japan (Hokkaido, Honshu, Shikoku, and Kyushu) and on the small islands surrounding them. Apodemus speciosus, the larger of the two species, showed substantial genetic variation, with a maximum of 3% sequence divergence, and remarkable phylogenetic subdivision with two major clades. One clade represents haplotypes from a central region, including Honshu, Shikoku, Kyushu, and their adjacent islands; the other clade includes haplotypes from Hokkaido and the peripheral islands, forming four subclades: a) Hokkaido, b) Sado Island, c) Satsunan Islands, and d) the Izu Islands. Sequence divergence among the four subclades was 1.0 to 1.5%, implying that A. speciosus colonized these geographic regions 0.2 to 0.3 million years ago, assuming a substitution rate of 2.4% per million years. The population on the Izu Islands has preserved haplotypes that are distinct from those in any other region, providing good evidence for the natural colonization of the volcanic islands of the Izu Islands. The cyt b sequence variation had no relation to the karyotypic dimorphism for the eastern (2n = 48) and western (2n = 46) geographic groups, between which a strict border exists at central Honshu. On the other hand, Apodemus argenteus, the smaller of the two species, showed a similar level of sequence divergence (maximum of 3%) but no substantial geographic differentiation: populations in Hokkaido, Sado, and Yakushima shared similar haplotypes with each of the central populations, suggesting that genetic exchanges occurred among the localities in the last 0.15 million years. The apparent genetic structure of the mitochondrial DNA found in the A. speciosus population might be caused solely by long-term existence in insular regions, presumably due to ecological superiority relative to A. argenteus.     

Molecular cytogenetic analysis of the highly repetitive DNA in the genome of Apodemus argenteus, with comments on the phylogenetic relationships in the genus Apodemus.

The DNA of Apodemus argenteus was digested with DraI, and the resultant DraI fragment of highly repetitive DNA was isolated and analyzed by DNA filter hybridization, cloning, sequencing, and fluorescence in situ hybridization (FISH). Southern blot hybridization and nucleotide sequencing revealed that most of the DraI fragment consisted of a 230-bp repeating unit and contained no sex-chromosome-specific nucleotide sequences. The DraI fragment included the CENP-B box-like sequence, with a strong homology to the human CENP-B box sequence. FISH revealed that the DraI fragment was specific to all pericentromeric C-band-positive regions, as well as to the C-block of the X chromosome. No hybridization signals were obtained from A. speciosus, A. peninsulae peninsulae, A.p. giliacus, A. agrarius, A. sylvaticus, A. semotus, or Mus musculus when the DraI fragment was used as probe. Peptide nucleic acid (PNA)-FISH using the CENP-B box-like sequence in the DraI fragments as probe suggested that this nucleotide sequence was also specific to all pericentromeric C-heterochromatic regions of A. argenteus chromosomes. Zoo-blot hybridization using DraI-digested genomic DNA from three species of Apodemus (namely, A. argenteus, A. speciosus, and A. peninsulae) and from Mus musculus strongly suggested that the consensus DraI fragment contained nucleotide sequences that were species-specific for A. argenteus. These results also suggest that A. argenteus is phylogenetically distant from other Apodemus species examined, as well as the possibility that the DraI fragment might be related directly to the delayed quinacrine mustard fluorescence of many pericentromeric C-heterochromatic regions of the chromosomes in A. argenteus.     

Intra- and interspecific morphological variation in the field mouse species Apodemus argenteus and A. speciosus in the Japanese archipelago: the role of insular isolation and biogeographic gradients

Two species of field mice, Apodemus argenteus and A. speciosus, occur in sympatry across the Japanese archipelago. The inter- and intraspecific patterns of morphological differentiation have been evaluated, using a Fourier analysis of the mandible outline. The relative importance of the effect of insular isolation and latitudinal climatic gradient on the size and shape of the two species was assessed by a comparison of the populations from the large island of Honshu and the surrounding small-island populations. The size variation in A. argenteus is correlated with the climatic gradient whilst the shape variation corresponds mainly to a random differentiation of the small-island populations from a Honshu-like basic morphological pattern. A. speciosus displays increased size on small islands, and its shape variation is related to both the climatic gradient and insularity. Finally, the two species are differentiated by both the size and shape of the mandible across the Japanese archipelago, suggesting that interspecific competition between both species is reduced via niche partitioning. Our results emphasize the importance of insular isolation on shape differentiation, but a part of the morphological differentiation is also related to the latitudinal climatic gradient. Isolation on small islands could have favoured such a response to environmental factors by lowering the gene flow that prevents almost any significant differentiation within Honshu populations.     

Epizootiological and epidemiological study of hantavirus infection in Japan

Epizootiological surveys on hantavirus infections in rodents were carried out in various areas of Japan, including the four major islands of Hokkaido, Honshu, Shikoku, and Kyushu from 2000 to 2003. A total of 1,221 rodents and insectivores were captured. Seropositive animals were found in Apodemus (A.) speciosus (5/482, 1.0%), Rattus (R.) norvegicus (4/364, 1.1%), R. rattus (3/45, 6.7%), and Clethrionomys (C.) rufocanus (7/197, 3.6%). The partial S segment was amplified from one seropositive R. rattus captured at Hakodate. The nucleotide sequence showed 96% identity with the Seoul virus (SEOV) prototype strain SR-11. In addition, we conducted an epidemiological survey on human hantavirus infection in a high-risk population, the personnel of the Japan Ground Self-defense Force on Hokkaido. One out of 207 human blood samples was positive for anti-hantavirus antibody by IFA, ELISA, and WB analysis. The result of the serotype specific ELISA indicates that this individual acquired SEOV infection. This study indicates that A. speciosus, R. norvegicus, R. rattus, and C. rufocanus carry hantaviruses as the reservoir animals in Japan. Infected R. rattus and R. norvegicus in port areas could be the sources of human SEOV infection and a threat to travelers and individuals working in seaports.     

First record of the larval parasitic nematode Rhabditis orbitalis from Japanese wood mice (Apodemus spp.)

Parasitic larvae of Rhabditis orbitalis (formerly confused with Pelodera strongyloides) were found in the conjunctival sacs of the eyes of Apodemus argenteus and A. speciosus from Japanese islands.     

Survey of Babesia microti infection in field rodents in Japan: records of the Kobe-type in new foci and findings of a new type related to the Otsu-type

Of 247 rodents comprising 5 genera and 7 species collected at 17 sites throughout Japan from 2003 to 2005, Babesia microti was detected microscopically and by polymerase chain reaction (PCR) in 36 rodents comprising 2 genera and 3 species from 12 sites. Based on the analysis of small subunit ribosomal RNA gene (SSUrDNA) sequences, the Kobe-type, the etiological type of the first Japanese case of human infection was found in Apodemus speciosus and Apodemus argenteus in Aomori, the northernmost prefecture of the Japanese mainland, while the U.S.-type was found on Hokkaido Island and the Otsu-type was widely distributed. In addition, a new Otsu-related type was detected exclusively in Eothenomys andersoni in Nagano, a prefecture in central Japan. The sequences of internal transcribed spacer 1 to 2 (ITS1/2) of the present Kobe- and Otsu-types were almost identical to those of the same types previously identified. The ITS1/2 sequence of the U.S.-type identified in Hokkaido in this survey was somewhat different from that of the U.S.-type strain originating from the U.S.A., with approximately 95% identity. This value was similar to the 94% identity found between the ITS1/2 sequences of the Otsu-type and the new Otsu-related type. The new Otsu-related type of B. microti was isolated as the Nagano strain, which was serologically differentiated from the other type strains of B. microti. The divergence and distribution of genotypes are important factors in investigating the epidemiology of human B. microti infection in Japan.     

A trend of central versus peripheral structuring in mitochondrial and nuclear gene sequences of the Japanese wood mouse, Apodemus speciosus

A phylogeographic analysis was performed on Japanese endemic wood mice (Apodemus speciosus) using nuclear interphotoreceptor retinol binding protein (IRBP) gene sequences (1,152 bp), together with previously published mitochondrial cytochrome b (cyt b) data. In the IRBP analysis, 40 haplotypes were recovered from 84 individuals by statistical and subcloning methods. Substantial sequence variation was determined from the IRBP data (pi=0.0047), and no significant evidence of recombination was detected. From the phylogenetic analysis, the 40 haplotypes fell into two major groups with geographic associations, irrespective of the karyotype groups (2n=46 and 2n=48), yielding a trend of central (Hokkaido, Honshu, Shikoku, Kyushu, and Sado) and peripheral (Izu, Oki, Tsushima, and Satsunan Is.) groupings. This geographic pattern is similar to that observed in the cyt b data, with a different insular grouping of Sado, Hokkaido, Izu, and Satsunan islands, and also to that of morphological features. In both gene data sets, nested clade analyses revealed allopatric fragmentation in the "peripheral island clades" and range expansion in the "central island clades." A mismatch analysis using cyt b data also suggested expansion of the central islands clade. Thus, the trend of central vs. peripheral structuring may be attributable to past demographic dynamics in the two distinct haplotype clades, such as range expansion of one clade in the central area of the Japanese Islands, leaving the other clade in the periphery.     

Mitochondrial DNA phylogeography of the red fox (Vulpes vulpes) in northern Japan

Mitochondrial DNA variation in the cytochrome b (cyt b) gene and the control region was examined in the red fox Vulpes vulpes from Japan, with special focus on the population divergence between Hokkaido and northern Honshu. Resultant haplotypes from Hokkaido were subdivided into two distinct groups (I and II), with an average genetic distance of 0.027 for cyt b. Divergence time is roughly estimated to be 1-2 million years ago, given that the conventional divergence rate of the mammalian cyt b gene is 2% per million years. Notably, Group II was only found in Hokkaido, whereas Group I comprised haplotypes from Honshu, Kyushu (Japan), eastern Russia, and Europe, as indicated by a comparison of our own data to the literature. On the other hand, judging from constructed trees, Group I haplotypes from Hokkaido appeared to differ from those from other parts of Japan, i.e., Honshu and Kyushu. This implies that Blakiston's Line, which demarcates the boundary between Hokkaido and Honshu, has been an effective barrier and has allowed the structuring of genetic variation in maternal lineages. Thus, these results suggest that the Hokkaido population, which is sometimes referred to as the distinct subspecies V. v. schrencki, has its own genetic background with multiple migration events and differs from the parapatric subspecies V. v. japonica found in Honshu and Kyushu.     

Molecular phylogeny and taxonomy of wood mice (genus Apodemus Kaup, 1829) based on complete mtDNA cytochrome b sequences, with emphasis on Chinese species

Phylogenetic relationships among 15 species of wood mice (genus Apodemus) were reconstructed to explore some long-standing taxonomic problems. The results provided support for the monophyly of the genus Apodemus, but could not reject the hypothesis of paraphyly for this genus. Our data divided the 15 species into four major groups: (1) the Sylvaemus group (A. sylvaticus, A. flavicollis, A. alpicola, and A. uralensis), (2) the Apodemus group (A. peninsulae, A. chevreri, A. agrarius, A. speciosus, A. draco, A. ilex, A. semotus, A. latronum, and A. mystacinus), (3) A. argenteus, and (4) A. gurkha. Our results also suggested that orestes should be a valid subspecies of A. draco rather than an independent species; in contrast, A. ilex from Yunnan may be regarded as a separate species rather than a synonym of orestes or draco. The species level status of A. latronum, tscherga as synonyms of A. uralensis, and A. chevrieri as a valid species and the closest sibling species of A. agrarius were further corroborated by our data. Applying a molecular clock with the divergences of Mus and Rattus set at 12 million years ago (Mya) as a calibration point, it was estimated that five old lineages (A. mystacinus and four major groups above) diverged in the late Miocene (7.82-12.74 Mya). Then the Apodemus group (excluding A. mystacinus) split into two subgroups: agrarius and draco, at about 7.17-9.95 Mya. Four species of the Sylvaemus group were estimated to diverge at about 2.92-5.21 Mya. The Hengduan Mountains Region was hypothesized to have played important roles in Apodemus evolutionary histories since the Pleistocene.     

Molecular phylogeny of wood mice (Apodemus, Muridae) in East Asia

Sequences of the mitochondrial cytochrome b (1140 bp) and nuclear IRBP (1152 bp) genes were used to assess the evolutionary history of Apodemus , using the complete set of Asian species. Our results indicate that speciation in Asia involved three radiations, which supports an earlier study. The initial radiation yielded A. argenteus (Japanese endemic), A. gurkha (Nepalese endemic), and the ancestral lineage of the remaining Asian species. This lineage subsequently diverged into four groups: agrarius-chevrieri ( agrarius group), draco-latronum-semotus ( draco group), A. peninsulae , and A. speciosus (Japanese endemic). The final step consisted of divergence within two species groups as a consequence of the geography of the Yunnan-Guizhou plateau and Taiwan. The ecological ability of two Apodemus species to inhabit one locality via niche partitioning likely drove the second radiation and shaped the basic geographical pattern seen today: A. argenteus and A. speciosus in Japan, A. agrarius and A. peninsulae in northern China, and the A. agrarius and A. draco groups in southern China. The three radiations are estimated to have occurred 7.5, 6.6, and 1.8–0.8 Mya respectively, using the IRBP clock, based on rat–mouse divergence 12 Mya.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 469–481.     

Phylogeography of Japanese population of Phelotrupes auratus (Coleoptera, Geotrupidae) inferred from mitochondrial DNA sequences

A partial sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene (745 bp) was determined for 57 specimens of a geotrupid beetle (Phelotrupes auratus) from throughout the Japanese archipelago. Of the 57 beetles examined, 42 haplotypes were identified. Phylogenetic trees inferred using maximum parsimony, neighbor joining, and Bayesian inference methods were highly congruent. Reconstructed phylogenetic relationships indicated that P. auratus from the Japanese archipelago was separated into two distinct lineages: Group A, which consisted of 35 haplotypes from Honshu, Shikoku, and Hokkaido Islands, and Group B, which consisted of seven haplotypes from Kyushu and Yakushima Islands. In addition, two sublineages were also recognized within Group A: Subgroup A-1, which consisted of 11 haplotypes from eastern Honshu and Hokkaido, and Subgroup A-2, which consisted of 10 haplotypes from western Honshu and Shikoku. Average genetic distances within Group A were positively correlated to geographic distance between sampling localities. Phylogenetic relationships among haplotypes did not correspond to subspecies classification.     

Molecular phylogeny of Japanese Leporidae,the Amami rabbit Pentalagus furnessi,the Japanese hare Lepus brachyurus,and the mountain hare Lepus timidus,inferred from mitochondrial DNA sequences

We determined mitochondrial 12S ribosomal RNA (rRNA) and cytochrome b (cyt b) gene sequences in three leporid species of Japan, the Amami rabbit Pentalagus furnessi from the Ryukyu Islands, the Japanese hare Lepus brachyurus from Honshu, and a Japanese form of the mountain hare Lepus timidus ainu from Hokkaido. We compared the sequences with those of other taxa of leporids available in databases. Phylogenetic trees of the 12S rRNA gene sequences indicated that the lineage of P. furnessi diversified during the generic radiation of the leporids at an ancient time, which was estimated to have been the middle Miocene. Cyt-b gene trees revealed that the lineage of L. brachyurus branched off at an early stage in the speciation of Lepus, probably at the beginning of the Pliocene. The cyt b sequences of L. t. ainu were somewhat distinct from those of continental conspecific populations; this lineage divergence is likely to have occurred during the middle or late Pleistocene. The results show that the three regions of the Japanese archipelago, Ryukyu, Honshu-Shikoku-Kyushu, and Hokkaido, now preserve their own leporid taxa, each with a different extent of genetic endemicity. It is possible that the zoogeographic traits of the Japanese leporids are a consequence of the evolutionary dynamics of leporids in East Asia, in that the radiation centers of leporids are likely to have shifted from tropical, through temperate, to arctic zones.     

Brachylaima asakawai sp. nov. (Trematoda: Brachylaimidae), a rodent intestinal fluke in Hokkaido,Japan, with a finding of the first and second intermediate hosts

In the 1970’s and 1980’s, an unknown species of the genus Brachylaima (Trematoda: Brachylaimidae) had been recorded from the intestines of Rattus norvegicus and Apodemus speciosus in Hokkaido, Japan. The rodent fluke was characteristic in extending a bilateral vitellarium till the level of posterior margin of anterior testis and in keeping almost the same-sized spherical ovary and testes. In this study, the rodent fluke was rediscovered from A. speciosus, Apodemus argenteus, and Myodes rufocanus in Hokkaido. The resultant parasite collection enabled us to make a mitochondrial DNA (mtDNA) barcode for tracking its intermediate hosts. The metacercaria of the rodent fluke was detected frequently from the kidney of three species of land snails (Discus pauper, Succinea lauta, and Ainohelix editha). However, its sporocyst with cercariae was found only from the hepatopancreas of D. pauper, a fairly small snail. The wide-spectrum of the second intermediate host seems to increase the chance of transmitting the parasite to various mammals and birds. The use of indigenous land snails as the first and second intermediate hosts, the distinctiveness of the mtDNA sequence, and the characteristic morphology of all the developmental stages prompted us to propose Brachylaima asakawai sp. nov. for the rodent intestinal fluke in Hokkaido. The present field survey suggests that the life cycle of the new species is primarily dependent on a predator-prey relationship between rodents and D. pauper.     

高原姬鼠一新艾美球虫记述(顶复合门,艾美球虫科)

粪检云南省昆明市太平镇捕获的31只高原姬鼠Apodemus chevrieri,在9只高原姬鼠中共发现了2种艾美球虫,自然感染率为29%,其中1种被命名为新种:齐氏艾美球虫Eimeria chevrieri sp.nov.。齐氏艾美球虫孢子化的卵囊椭圆形,大小为21·2μm×16·3μm(22·2~19·7μm×17·3~15·6μm)。卵囊壁光滑,单层,厚约1·0μm;无胚孔和卵囊余体。有1~2个极体,极体形状不规则,直径1·0~2·0μm。卵圆形的孢子囊大小为11·2μm×7·5μm(12·3~10·3μm×8·3~6·8μm),有孢子囊余体,且主要分布在2个子孢子的中间,斯氏体扁豆形,大小为1·0μm×0·3μm,亚斯氏体亚球形,大小为2·5μm×1·5μm。子孢子在孢子囊里面头尾相接,在其宽端有1个明显的反光体,直径约3μm。模式标本保存在云南大学标本馆。齐氏艾美球虫,新种Eimeria chevrieri sp·nov.(图1~2,4)寄生于姬鼠属,具有椭圆形的卵囊,卵囊壁具有光滑、无色、单层特点的艾美球虫有3种:E.gomurica Musaev and Veisov,1963,E.kaunensis Arnastauskiene et al.,1978和E.gandobica Musaev and Veisov,1965。E.gomurica、E.kaunensis与本种的主要区别是卵囊较小且有卵囊余体;E.gandobica与本种的主要区别是卵囊呈宽椭圆形,卵囊和孢子囊较小(19·0μm×16·8μmvs·21·2μm×16·3μm;8·0μm×5·0μmvs·11·2μm×7·5μm),孢子囊余体少,无反光体和亚斯氏体。寄生于姬鼠属,具有椭圆形的卵囊,卵囊壁具有光滑、2层特点的艾美球虫有3种:E.alorani Hurková et al.,2005、E.apodemi Pell啨rdy1974和E.zaurica Musaev and Veisov,1965。E.zaurica与本种的主要区别是具有卵囊余体;E.alorani的卵囊和孢子囊比本种大的多(26·9μm×19·3μmvs.21·2μm×16·3μm),且其孢子囊余体形成一个直径约4~5μm的球状结构;E.apodemi的孢子化卵囊呈宽椭圆形,经常不对称,无极体和斯氏体。该种区别其它种的关键特征是:1)孢子化卵囊椭圆形,卵囊壁光滑、单层、无色;2)有极体;3)孢子囊有亚斯氏体。模式标本,含孢子化卵囊的齐氏姬鼠粪便保存在云南大学生物系,标本编号:2006047;齐氏姬鼠标本保存于云南大学标本馆,标本编号20060081。词源:种名源自宿主种名。     

Distribution of Borrelia Species Associated with Lyme Disease in the Subalpine Forests of Nagano Prefecture,Japan

We surveyed the natural distribution of Borrelia species associated with Lyme disease in the subalpine forests of Nagano prefecture, Japan, during 1993-94. Tick-derived isolates (n = 112) from Ixodes persulcatus and rodent-derived isolates (n = 55) from Apodemus argenteus, Apodemus speciosus, Eothenomys andersoni, Eothenomys smithii, and Microtus montebelli were classified by rRNA gene restriction fragment length polymorphism analysis (RFLP ribotyping). Ribotype group IV (an intraspecific variant of Borrelia garinii) was predominant among the tick isolates. It was also isolated repeatedly from the rodents. Ribotype group III (Borrelia afzelii) was detected in low frequencies among the tick and rodent isolates. The data suggest that humans are likely to be exposed to the group IV when they are bitten by I. persulcatus ticks.     

New host and locality records of coccidia (Apicomplexa: Eimeriidae) from rodents in the southwestern and western United States.

One hundred forty-seven murid and heteromyid rodents were collected from various sites in the southwestern and western United States (Arizona, Colorado, New Mexico, Texas, and Utah) and Baja California Norte, Mexico, and their feces were examined for coccidial parasites. Of these, 53 (36%) were infected with at least 1 coccidian; 45 of 53 (85%) of the infected rodents harbored only 1 species of coccidian. Infected rodents included: 10 of 22 (45%) Neotoma albigula, 3 of 11 (27%) Neotoma floridana, 2 of 14 (14%) Neotoma lepida, 15 of 29 (52%) Neotoma micropus, 5 of 8 (63%) Peromyscus crinitis, 6 of 6 (100%) Peromyscus difficilis, 1 of 2 (50%) Peromyscus eremicus, 9 of 34 (26%) Sigmodon hispidis, and 2 of 3 (67%) Sigmodon ochrognathus; 4 Neotoma cinerea, 3 Neotoma devia, 3 Neotoma mexicana, 1 Peromyscus maniculatus, 1 Onychomys leucogaster, 1 Onychomys torridus, 3 Chaetodipus fallax, and 2 Chaetodipus penicillatus were negative. Although no new species was found, the following coccidians were identified from infected rodents: Eimeria albigulae from N. albigula, N. floridana, and N. micropus, Eimeria antonellii from N. albigula and N. micropus, Eimeria ladronensis from N. albigula, N. floridana, N. lepida, and N. micropus, Eimeria arizonensis and Eimeria lachrymalis from P. crinitis and P. difficilis, Eimeria lachrymalis from P. eremicus, Eimeria tuskeegensis from S. ochrognathus, and Eimeria roperi, Eimeria sigmodontis, Eimeria tuskeegensis, Eimeria webbae, and an unidentified species of Eimeria from S. hispidis. This report documents 12 new host and several distributional records for Eimeria species from murid rodents in Arizona, Texas, and Utah.     

Coccidian parasites (Apicomplexa: Eimeriidae) from insectivores. III. Seven new species in shrews (Soricidae: Soricinae) from Canada, Japan, and the United States

Since May 1979, 458 shrews (Blarina sp. and Sorex spp.) representing 20 species collected in Canada, Japan, and the United States were examined for coccidia; 110 (24%) had oocysts in their feces, including 8 of 21 (38%) B. brevicauda from Massachusetts, Ohio, Pennsylvania, and Vermont; 2 of 7 (29%) S. caecutiens from Hokkaido and Honshu; 14 of 63 (22%) S. cinereus from Colorado, New Mexico, Pennsylvania, Vermont, Manitoba, and Ontario; 3 of 7 (43%) S. fontinalis from Pennsylvania; 11 of 16 (69%) S. fumeus from Massachusetts, Minnesota, Pennsylvania, Vermont, and Ontario; 1 of 4 (25%) S. haydeni from Minnesota; 6 of 8 (75%) S. longirostris from Florida and Virginia; 1 of 2 (50%) S. ornatus from California; 5 of 12 (42%) S. pacificus from California and Oregon; 13 of 41 (32%) S. palustris from California, Colorado, and New Mexico; 1 of 2 (50%) S. tenellus from California; 11 of 105 (10%) S. trowbridgii from California, Oregon, and Washington; 10 of 48 (21%) S. unguiculatus from Hokkaido; and 24 of 112 (21%) S. vagrans from Arizona, California, Colorado, New Mexico, Oregon, and Washington. The following coccidians were identified from infected shrews: Eimeria brevicauda n. sp. from B. brevicauda; Eimeria fumeus n. sp. from S. fumeus, S. pacificus, S. unguiculatus, and S. vagrans; Eimeria inyoni n. sp. from S. tenellus; Eimeria palustris n. sp. from S. cinereus, S. fontinalis, S. fumeus, S. haydeni, S. longirostris, S. ornatus, S. pacificus, S. palustris, S. tenellus, S. trowbridgii, and S. vagrans; Eimeria vagrantis n. sp. from S. fumeus, S. trowbridgii, and S. vagrans; Isospora brevicauda n. sp. from B. brevicauda; and Isospora palustris n. sp. from S. pacificus, S. palustris, S. trowbridgii, S. unguiculatus, and S. vagrans. The world literature on coccidian parasites of shrews (16 eimerians and 3 isosporans exclusive of the 7 new species described here) is reviewed.     

An eimeriid species (Apicomplexa: Eimeriidae) that parasitises the gallbladder and bile-duct of three species of Takydromus (Sauria: Lacertidae) in eastern and southeastern Asia

Eimeria takydromi n. sp., a coccidian infecting the gall-bladder epithelium and bile-ducts, was found to parasitise three Takydromus species: T. tachydromoides of Honshu, Japan; T. smaragdinus of Amami Oshima, Ryukyu Islands, Japan; and T. sexlineatus of Thailand. Although differences were found in the mean oöcyst and sporocyst indices among the different hosts, the considerable overlap in morphometric characters demonstrated conspecificity. Eimeria takydromi is an addition to the symbiotic complex associated with Takydromus spp. in eastern and southeastern Asia that includes Plasmodium sasai, Trypanosoma takydromi, Schellackia sp. and Lizard Erythrocytic Virus. These host-symbiote associations may have persisted since a lacertid ancestral to the modern species of Takydromus dispersed throughout the region from the late Pliocene.     

Eimeria hajeki n. sp. (Apicomplexa: Eimeriidae), a new coccidian parasite of the pygmy chameleon, Rampholeon temporalis (Matschie, 1892) (Reptilia: Chamaeleonidae) from Usambara Mountains, Tanzania.

Fecal samples from 10 pygmy chameleons, Rampholeon temporalis (Matschie, 1892), an endemic species of the Usambara Mountains in northeastern Tanzania, were examined for coccidian parasites. Two (20%) chameleons were found to be passing oocysts of Eimerio Schneider. Comparison with other species of Eimeria indicates that the coccidian found represents a new species. Sporulated oocysts of Eimeria hajeki n. sp. are oval, 30.2 (29-31) by 23.5 (22-25) microm, with a shape index (length/width) of 1.3 (1.2-1.4) and a 2-microm-thick rough, bilayered wall. Micropyle and polar granule are absent. Sporocysts are oval to rhomboidal, 10.8 (9-11.5) by 8.8 (7.5-10) microm, with a shape index of 1.2 (1.15-1.3) and a wall composed of 2 valves joined by a suture.     

Effects of acorn masting on population dynamics of three forest-dwelling rodent species in Hokkaido,Japan

The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns between the three species may be due to differences in their physiological tolerance to tannins.