著者
KUBOTA,SHIN
出版者
Zoological Society of Japan
雑誌
Zoological science
巻号頁・発行日
vol.9, no.2, 1992-04-15

A new hydromedusa Eirene lacteoides (Leptomedusae; Eirenidae) from Toba, Mie Prefecture, Japan is described based on the laboratory-reared 18 male medusae and 33 immature ones. The new species resembles Eirene lactea (Mayer, 1900) in having distal projections of peduncle, but can be distinguished by the presence of an adaxial papilla on every well-developed tentacular bulb and even on some small tentacular bulbs bearing very short tentacles. The development of medusa, the nematocyst equipment, and the distributional records of E. lacteoides are also described.
著者
Mukai Takahiko Sato Torao Naruse Kiyoshi Inaba Kazuo Shima Akihiro Morisawa Masaaki
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.13, no.1, pp.175-183, 1996-02-15
被引用文献数
1

The genetic relationships and taxonomic status of 7 taxa belonging to the genus Tridentiger (Pisces, Gobiidae) were investigated by means of analysis of allozymic variation at 14 loci. The results suggest that the two taxa "T. obscurus" and "T. brevispinis" which are sympatric and morphologically similar are reproductively isolated and are highly divergent from each other (the genetic distance values are 0.501-0.707). It is also suggested that "T. brevispinis" and "T. kuroiwae" are genetically different enough from each other to deserve subspecies at least. The other 4 taxa, "T. barbatus", "T. nudicervicus", "T. trigonocephalus" and "T. bifasciatus", are genetically divergent each and are considered to be 4 biological species. A dendrogram showing the phylogenetic relationships of the 7 taxa was constructed from the genetic distances.
著者
Yamagishi Ayaka Yao Izumi Johnson Kevin P. Yoshizawa Kazunori
出版者
Zoological Society of Japan
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.31, no.6, pp.383-389, 2014-06
被引用文献数
2 2

Data from gene sequences and morphological structures were collected for the gull feather lice, Saemundssonia lari, Quadraceps punctatus, and Q. ornatus, parasitizing Larus crassirostris and L. schistisagus. Saemundssonia lari was collected from both gull species, and no detectable morphological and genetic differences were found between lice collected from the two different hosts. In contrast, Q. punctatus was only collected from L. crassirostris, whereas Q. ornatus was only collected from L. schistisagus. The two Quadraceps species were genetically highly divergent, and body-size differences corresponding to the gull's body size (Harrison's rule) were also detected between them. Both Quadraceps species were collected from the interbarb of the remex or rectrix, and a match in body size between the louse and the interbarb space may be important in escape from host preening defenses. In contrast, Saemundssonia is a head louse, inhabiting the finer feathers of the head and neck, which the bird cannot preen. A close match to host body size may be less important for lice in the head microhabitat. The differences in the pattern of host-specificity between Saemundssonia and Quadraceps on the two focal host species of this study were probably due to their different microhabitat preferences. More broadly, comparisons of the gene sequences of S. lari and Q. punctatus to those from other gull hosts showed that genetically almost undifferentiated populations of both species were distributed on wide range of gull species. Frequent interspecific hybridization of gulls is one possible factor that may allow these lice to maintain gene flow across multiple host species.
著者
Tomioka Shinri Kondoh Tomohiko Sato-Okoshi Waka Ito Katsutoshi Kakui Keiichi Kajihara Hiroshi
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.33, no.5, pp.545-554, 2016-10
被引用文献数
18

Capitella teleta Blake et al., 2009 is an opportunistic capitellid originally described from Massachusetts (USA), but also reported from the Mediterranean, NW Atlantic, and North Pacific, including Japan. This putatively wide distribution had not been tested with DNA sequence data; intraspecific variation in morphological characters diagnostic for the species had not been assessed with specimens from non-type localities, and the species status of the Japanese population(s) was uncertain. We examined the morphology and mitochondrial COI (cytochrome c oxidase subunit I) gene sequences of Capitella specimens from two localities (Ainan and Gamo) in Japan. Specimens from Ainan and Gamo differed from C. teleta from Massachusetts in methyl-green staining pattern, shape of the genital spines, and shape of the capillary chaetae; we concluded that these characters vary intraspecifically. Species delimitation analyses of COI sequences suggested that worms from Ainan and Massachusetts represent C. teleta; these populations share a COI haplotype. The specimens from Gamo may represent a distinct species and comprise a sister group to C. teleta s. str.; we refer to the Gamo population as Capitella aff. teleta. The average Kimura 2-parameter (K2P) distance between C. teleta s. str. and C. aff. teleta was 3.7%. The COI data indicate that C. teleta actually occurs in both the NW Atlantic and NW Pacific. Given the short planktonic larval duration of C. teleta, this broad distribution may have resulted from anthropogenic dispersal.
著者
Endo Hideki Niizawa Nobuharu Komiya Teruyuki Kawada Shinichiro Kimura Junpei Itou Takuya Koie Hiroshi Sakai Takeo
出版者
Zoological Society of Japan
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.24, no.10, pp.1005-1011, 2007-10
被引用文献数
13

The gross anatomy of the mastication system of the giant anteater (Myrmecophaga tridactyla) was examined by means of three-dimensional image analysis. The anteater rotates the mandibles medially and laterally to control its tongue when it is elongated and to house it when it is relaxed. Three-dimensional CT image analysis demonstrated that the shape and size of the oral cavity changes drastically when the mandibles are rotated. The oral cavity expands bilaterally when the dorsal part of the mandibles bend medially. Macroscopic observations and muscle-weight data supported the observation that the superficial temporal and medial pterygoid muscles act as the main medial and lateral rotators of the mandible, respectively. The low height of the mandibular ramus and the incomplete zygomatic arch in this species represent adaptations for the rotational movement of the mandibles, since they both contribute to the medially oriented transmission of force from the temporal muscles and to preventing collision between the mandibles and the cranium during the rotational movement.
著者
Nishi Hirotaka Sota Teiji
出版者
Zoological Society of Japan
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.24, no.5, pp.475-485, 2007-05
被引用文献数
7

We studied genetic variation within the Japanese land snail Euhadra herklotsi, which occurs on Kyushu and the surrounding islands, using partial sequences of the mitochondrial COI gene and nuclear ITS2 genes. The phylogenetic analysis revealed the existence of two major clades: clade N in the north and clade S in the south. These clades were parapatric and overlapped in southern Kyushu. Genetic divergence was high in clade N, whereas it was much lower in clade S. In addition, isolation-by-distance within each clade was implied. Since no current geographical barriers separate these clades, the genetic structure of clade S might have been influenced by historical events, such as volcanic activity, and a resulting population bottleneck followed by range expansion. The genital characteristics of clade-S snails were distinct from those of clade-N snails, and snails in both clades were sympatric at one locality. The shells of clade-N snails were generally larger than those of clade-S snails, but the shell-size variation within each clade could not be explained simply by environmental variables. Our study suggests that E. herklotsi likely consists of two sibling species. The taxonomic status of the previously proposed subspecies of E. herklotsi and related species requires reassessment.
著者
Fujikura Katsunori Fujiwara Yoshihiro Kawato Masaru
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.23, no.8, pp.733-740, 2006-08-25
被引用文献数
60

A new whale-bone-eating polychaete species of the genus Osedax was found on sperm whale carcasses submerged off Cape Nomamisaki, Kyushu, Japan, at a depth of approximately 200m. The new species, Osedax japonicus, is the fourth known species of the genus Osedax and the first species from the western Pacific. Female O. japonicus specimens (1) form dense clusters on whale carcasses; (2) have a body composed of crown, trunk, and root structure; (3) lack a digestive tract; and (4) have bacterium-like particles in the tissue of the root structure. Osedax japonicus shares all these characteristics with O. rubiplumus and O. frankpressi, and items (1) to (3) with O. mucofloris. Osedax japonicus is easily distinguished from the other three known species by oviduct morphology, body length, and palp coloration in females. No males of O. japonicus have yet been found.
著者
Gibson Ray Sundberg Per
出版者
社団法人 日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.18, no.9, pp.1259-1273, 2001-12-10
参考文献数
59
被引用文献数
1 7

Three species of marine nemerteans described and illustrated from Queensland and the Great Barrier Reef, Australia, include one new genus and two new species: these are the monostiliferous hoplonemerteans Thallasionemertes leucocephala gen. et sp. nov. and Correanemertes polyophthalma sp. nov. A new colour variety of the heteronemertean Micrura callima is also reported, this species previously only being known from Rottnest Island, Western Australia. A key for the field identification of the marine nemerteans recorded from coastal Queensland and the Great Barrier Reef is provided.
著者
Tomioka Shinri Kakui Keiichi Kajihara Hiroshi
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.35, no.5, pp.436-445, 2018-10
被引用文献数
2

Capitellids have emerged as monophyletic in most but not all recent molecular phylogenies, indicating that more extensive taxon sampling is necessary. In addition, monophyly of most or all capitellid genera was questionable, as some diagnostic characters vary ontogenetically within individuals. We tested the monophyly of Capitellidae and eight capitellid genera using phylogenetic analyses of combined 18S, 28S, H3, and COI gene sequences from 36 putative capitellid species. In our trees, Capitellidae formed a monophyletic sister group to Echiura, and Capitella was also monophyletic, separated by a long branch from other capitellids. Well-supported clades each containing representatives of different genera, or containing a subset of species within a genus, indicated that Barantolla, Heteromastus, and Notomastus are likely not monophyletic. We mapped three morphological characters traditionally used to define capitellid genera (head width relative to width of first segment, number of thoracic segments, and number of segments with capillary chaetae) onto our tree. While Capitella showed unique character states, states in the other genera were decidedly not phylogenetically informative. Morphology-based capitellid taxonomy will require a fine-scale reevaluation of character states and detection of new characters.
著者
Kakui Keiichi Katoh Toru Hiruta Shimpei F. Kobayashi Norio Kajihara Hiroshi
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.28, no.10, pp.749-757, 2011
被引用文献数
19

Phylogenetic relationships within Tanaidacea were analyzed based on sequence data for the 18S rRNA gene. Our results strongly supported a monophyletic group composed of Neotanaidae, Tanaoidea, and Paratanaoidea, with the first two taxa forming a clade. These results contradict three previously suggested hypotheses of relationships. Based on the molecular results, and considering morphological similarities/differences between Neotanaidomorpha and Tanaidomorpha, we demoted Suborder Neotanaidomorpha to Superfamily Neotanaoidea within Tanaidomorpha; with this change, the classification of extant tanaidaceans becomes a two-suborder, four-superfamily system. This revision required revision of the diagnoses for Tanaidomorpha and its three superfamilies. The results for Apseudomorpha were ambiguous: this taxon was monophyletic in the maximum likelihood and Bayesian analyses, but paraphyletic in the maximum parsimony and minimum evolution analyses.
著者
Kakui Keiichi Hayakawa Yoshinobu Katakura Haruo
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.34, no.2, pp.129-136, 2017-04
被引用文献数
5

We investigated the life cycle of the tanaidid Zeuxo sp. 1 (Crustacea: Peracarida: Tanaidacea), which lives epiphytically in dwelling tubes on the algae Sargassum spp. and Neorhodomela aculeata in Oshoro Bay, Hokkaido, Japan. We obtained data on its population size distribution, age structure, and reproductive phenology through monthly sampling from April 2011 to June 2012. From these data, we detected an overwintering group (F0) that arises from mancae that are released in autumn, overwinters, reproduces the following spring, and then disappears. The overwintering group produces mancae (F1) that reach maturity and themselves reproduce within six weeks after release; the F1, mancae give rise to an F2 and possibly an F3 generation within a single summer. We refer to individuals that reproduce in the same summer that they were released as the ‘annual group’. Reproduction overall was restricted to the period from May to October, when the seasurface temperature exceeded 10°C. During both years, overwintering females first became reproductive in May. Reproduction in the annual group began in June and continued through mid-October. Mancae were observed in samples from June through October. The two groups differed significantly in size at reproduction; compared to the annual group, females in the overwintering group reproduced at larger minimum and average body sizes, and males began to express enlarged chelae, a secondary sexual character, at a larger size. The difference in size at maturity may be related to the differences in water temperature during the main period of growth and maturation.
著者
Ota Kinya G. Kuratani Shigeru
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.23, no.5, pp.403-418, 2006-05-25
被引用文献数
1 48

Due to their curious phylogenetic position and anatomy, hagfishes have attracted the interest of zoologists, especially in the context of vertebrate evolution. Embryological information on these animals is now also needed in the field of evolutionary developmental biology (Evo-Devo), as it is expected to provide hints about the origin of vertebrate traits, whether the hagfishes are an in- or outgroup of vertebrates. This review summarizes the importance of hagfish embryology from a phylogenetic perspective, and the history of attempts to obtain hagfish eggs and embryos. Clearly, the main difficulty associated with these animals is their deep-sea habitat. To circumvent this problem, this review also discusses the future prospects for obtaining embryological material, both from the wild and in the laboratory.
著者
Kurihara Takeo Shikatani Mayu Nakayama Kouji Nishida Mutsumi
出版者
Zoological Society of Japan
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.23, no.11, pp.999-1008, 2006-11
被引用文献数
7

In many benthic organisms with a planktonic larval stage, local populations have different morphology. Such difference may arise from some of the following proximate mechanisms. “Local recruitment (LR)”: no larvae move between local populations, and segregated populations possess alleles coding for locally adaptive morphology. “Intragenerational selection (IS)”: larvae move between local populations, and individuals with alleles for locally adaptive morphology survive after recruitment. “Phenotypic plasticity (PP)”: larvae move between local populations and show phenotypic plasticity to adapt to a locality after recruitment. We examined which mechanism explains our finding that a planktonic developer Turbo coronatus coronatus (Gastropoda) had significantly longer spines on its shell on more exposed shores at scales of < 2 km. Experiments at Ishigaki Island, Okinawa, Japan, showed the following results. (a) Shorter- and longer-spined populations occurring within 2 km showed non-significant ϕ low st values (−0.0040 to 0.00095) for the mitochondrial DNA COI region. This suggests no segregation of the local populations, supporting the mechanisms IS and PP. (b) T. c. coronatus generated significantly longer spines 70 days after being transplanted to the habitat of a longer-spined population, supporting IS and PP. (c) Individuals caged in the sea for 79 days generated longer spines than individuals in the laboratory, supporting PP. In conclusion, shore-specific morphology of T. c. coronatus arises most likely from phenotypic plasticity and possibly from intragenerational selection.
著者
Matsui Masafumi Nishikawa Kanto Misawa Yasuchika Tanabe Shingo
出版者
Zoological Society of Japan
雑誌
Zoological Science (ISSN:02890003)
巻号頁・発行日
vol.24, no.7, pp.746-751, 2007-07
被引用文献数
3

We conducted an electrophoretic survey to examine systematic relationships of a lotic-breeding salamander Hynobius okiensis endemic to Dogo Island of the Oki Islands, Japan, with several lentic and lotic-breeding Japanese species. Genetically H. okiensis with 2n=56 chromosomes was closer to the lentic-breeding H. nebulosus group (H. nebulosus and H. dunni) with the same chromosome number than to the lotic-breeding H. naevius group (H. naevius and H. kimurae) and H. boulengeriwith 58 chromosomes. Chromosome number reduction from 58 to 56, possibly accompanied with a change in breeding environment from streams to still waters, is estimated to have first occurred in the nebulosus group of Hynobius. A reversal only in breeding habits then seems to have followed in steep, montane environments of the small island of Dogo, resulting in the speciation of H. okiensis.
著者
Kawada Shin-ichiro Harada Masashi Obara Yoshitaka Kobayashi Shuji Koyasu Kazuhiro Oda Sen-ichi
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.18, no.7, pp.1003-1010, 2001-09-20
被引用文献数
14 23

A detailed analysis was done on the karyotypes of four species of mole in the genera Euroscaptor and Mogera using a G-banding technique. All four species examined had a chromosome number of 2n = 36, as reported previously. Euroscaptor mizura and M. wogura from Aichi Prefecture had almost the same chromosome constitution and G-banding patterns. These common karyotypes were considered to be equivalent to the hypothetical ancestral karyotype of Mogera, since two distinct genera derived from an ancestor share G-banding homologies. According to this hypothesis, the karyotype of M. imaizumii might have been derived from the ancestral karyotype through pericentric inversion in one pair of acrocentrics, chromosome 11. Two geographically isolated populations of M. tokudae had different karyotypes : the Echigo population had the same karyotype as M. imaizumii, whereas the Sado population had a derivative karyotype that was able to be explained by pericentric inversions in three pairs of acrocentrics, remaining chromosome 11 as subtelocentric. Mogera wogura from South Korea differed considerably in terms of chromosome constitution from the Japanese population of M. wogura. However, we deduced that pericentric and paracentric inversions in four pairs of acrocentrics would explain the karyotype differences between the Japanese and Korean populations. Furthermore, from the morphology of chromosome 11, we can conclude that the Korean mole was derived from primitive M. wogura through four inversions, quite separately from the lineage of M. imaizumii and M. tokudae. Thus, inversion rearrangements appear to have played a major role in the chromosomal evolution of Japanese talpine moles.
著者
Sawada Isamu Koyasu Kazuhiro Shrestha Krishna Chandra
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.10, no.1, pp.147-154, 1993-02-15
被引用文献数
2

Two new species of the cestode parasite, Staphylocystis (Staphylocystis) kathmanduensis sp. nov. and S. (S.) trisuliensis sp. nov. are described from the house shrews, Suncus murinus of Kathmandu and Trisuli, respectively. The former is related to, but different from S. (S. ) delicata Sawada et Koyasu, 1991 in the length and number of the rostellar hooks, and the size of the rostellum. The latter is related to, but different from S. (S. ) dsinezumi Sawada et Koyasu, 1990 in the rostellar hooks. The house shrew, Suncus murinus, one kind of the commensal mammals, are widly distributed in Asia and are found infected with a great number of different cestodes. The difference between the two cestode species infecting Suncus murinus collected respectively at Kathamandu and Trisuli is discussed according to the hosts's behavior patterns.
著者
Harada Masashi Ando Akiro Tsuchiya Kimiyuki Koyasu Kazuhiro
出版者
社団法人日本動物学会
雑誌
Zoological science (ISSN:02890003)
巻号頁・発行日
vol.18, no.3, pp.433-442, 2001-04-10
被引用文献数
4 16

Karyotypes of the greater Japanese shrew-mole, Urotrichus talpoides (Talpidae), collected from 57 localities in Japan were studied by conventional, G- and C-band staining techniques to elucidate geographical chromosomal variations, the mechanism of changes in chromosomes, and the distribution patterns of karyotypic races. Shrew-mole samples examined could be divided geographically into two slightly divergent chromosomal forms designated as the western and eastern races. These two karyotypic races had the same diploid number (34) and fundamental number (64), but they had autosomes with different makeups. A comparison of conventional karyotypes showed a distinct intraspecific variation in shape of autosomal pair no. 14 which was classified as subtelocentric in the western race and as metacentric in the eastern race. G- and C-banding analyses revealed that karyotypic variation found in no. 14 pair was involved in pericentric inversion and quantitative changes in constitutive heterochromatin. Intraspecific and geographical variation in chromosomes caused by such karyological events is rare and unique among members of the family Talpidae examined so far. Furthermore, our results demonstrated that the clear boundary between the two parapatric karyotypic races was actually located along the Kurobe-Fuji line in the central part of Honshu, but not along the Owari-Tsuruga isthmian line previously postulated by Tsuchiya (1987,1988). Zoogeographical implications of the boundary of parapatric distribution in U. talpoides are also discussed.