著者

Kajihara Hiroshi Gibson Ray Mawatari Shunsuke F.

出版者

日本動物学会

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.20, no.4, pp.491-500, 2003-04

被引用文献数

7

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Potamostoma shizunaiense gen. et sp. nov. (Nemertea: Hoplonemertea: Monostilifera) is described from the mouth of the River Shizunai, Hokkaido, Japan. This genus is readily distinguished from other monostiliferans by an oesophagus opening far anteriorly into the rhynchodaeum, a well developed excretory system extending the whole body length, terminals of the excretory collecting tubules situated between the body wall circular muscle layer and the dermis, and bilobed testes in males.

著者

Kakui Keiichi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.39, no.2, 2022-04

被引用文献数

1

---

I report digenean metacercariae from Staurozoa, which were not previously known as digenean hosts. The host species, Haliclystus tenuis Kishinouye, 1910, was collected from algae in Oshoro Bay, Hokkaido, Japan, and contained metacercariae in the mesoglea. The metacercariae were encysted; cysts were oval, 93 μm long by 64 μm wide in one live individual. For the digenean, I generated partial sequences for the 18S rRNA (1585 bp) and 28S rRNA (1672 bp) genes, and the region spanning the 3′ end of the cytochrome c oxidase subunit gene and the 5′ end of the 16S rRNA gene, including the threonine tRNA gene (868 bp in total). Phylogenetic reconstructions based on combined 18S+28S datasets showed the digenean to belong in Opecoelidae, members of which utilize marine or freshwater teleost fishes as definitive hosts, and placed it in Plagioporinae (sensu lato) clade C within Opecoelidae.

著者

Kakui Keiichi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.36, no.6, pp.468-470, 2019-12

被引用文献数

2

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This study describes shell-exchange behavior in the hermit-crab-like tanaidacean Macrolabrum sp. (Pagurapseudidae: Pagurapseudinae) under captive conditions. I observed one shell exchange by Macrolabrum sp., the behavioral sequence of which was as follows: a shell-carrying tanaidacean 1) grasped the edge of the aperture of an empty gastropod shell with its right cheliped; 2) inspected the condition inside the shell four times by inserting the anterior portion of its body into the shell; and 3) moved into the shell, posterior end (pleotelson) first. The elapsed time from the initial grasping of the empty shell to completing the move into it was 2 min 20 sec. In contrast to a Pagurapseudes tanaidacean and hermit crabs, the individual of Macrolabrum sp. did not examine the external surface of the shell during the single shell exchange observed.

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

Kakui Keiichi Fujiwara Yoshihiro

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.37, no.4, pp.303-306, 2020-08

被引用文献数

3

---

We report on the behavior of a deep-sea tanaidacean, Gigantapseudes sp. (Apseudomorpha: Gigantapseudidae), recorded at the depths of 6446–6447 m by the manned submersible Shinkai 6500. From recordings of at least three individuals walking on the sea floor, we confirm that Gigantapseudes sp. is epibenthic, as previously inferred from leg shape. One individual was recorded entering a hole. All individuals in the videos kept pereopods 4 raised from the seafloor while walking, implying that those legs have a function other than for walking, such as mechano- or chemoreception, or posture control. Our in situ observations of behavior are the first for any deepsea tanaidacean and illustrate the importance of recording high-resolution videos in the deep sea and archiving them for future use. Our identification of Gigantapseudes sp. from video footage provides the first record of this genus from Japanese waters and extends the northern limit of the known generic distribution.

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

6 2

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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

Shiraki Shoki Kakui Keiichi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.39, no.3, pp.270-274, 2022-06

被引用文献数

2

---

Although isopods in Anthuroidea are predators, there is little information on their predatory behavior. In this study, we investigated predation by the paranthurid Paranthura japonica, which was originally described from northern Japan but has recently been reported as an invasive alien species in western America and Europe. Six crustacean species (two isopods, two amphipods, and two tanaidaceans, one of which does not co-occur with P. japonica in the wild) and one pycnogonid species were used as prey candidates in our experiments. Paranthura japonica preyed on all candidate species except the pycnogonid, grasping them with its falciform pereopods, inserting its piercing-type mouthparts, and sucking out the internal contents of the prey. Cannibalism or scavenging was observed when several P. japonica individuals were put in a single aquarium. This study showed that P. japonica is an aggressive predator; it consumed various crustaceans, including one it never encounters in the wild. Our results suggest that P. japonica will have a high impact on alien ecosystems it invades as a predator on native crustaceans. Cytochrome c oxidase subunit (COI) nucleotide sequences for putative P. japonica from Oshoro, Japan and a topotypic individual from Muroran confirmed that the population we dealt with was P. japonica.

著者

Munakata Mizuho Tanaka Hayato Kakui Keiichi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.38, no.3, pp.287-296, 2021-06

被引用文献数

7

---

We describe the cypridoidean ostracod Heterocypris spadix sp. nov. from brackish water on Okinawa Island, Japan. The species closely resembles Heterocypris salina (Brady, 1868) but differs in that (1) the marginal infolds on valves are less developed, (2) the tubercles on the anterior margin of the right valve are completely covered by the selvage and invisible in inner view, and (3) the calcified inner lamella on the ventral margin of the left and right valves is scarcely evident in inner view, as the ventral margins of the valves bend inwardly. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA genes in H. spadix for future DNA barcoding and phylogenetic analyses. Our sample contained only females. A breeding experiment revealed that H. spadix females reproduce parthenogenetically. Another experiment showed that H. spadix has low tolerance to desiccation, with all individuals at 25°C dying between 1–2 hours after removal from water. We amplified and sequenced a partial 16S rRNA sequence for the endosymbiotic bacterium Cardinium from H. spadix. Infection by Cardinium may be related to the parthenogenetic reproductive mode we observed in H. spadix.

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

9

---

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

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

29

---

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

17

---

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

Kato Atsushi Kuroda 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.21, no.12, 2004-12-25

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

66

---

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

Kajihara Hiroshi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.24, no.4, pp.287-326, 2007-04

被引用文献数

39

---

A literature-based taxonomic catalogue of the nemertean species (Phylum Nemertea) reported from Japanese waters is provided, listing 19 families, 45 genera, and 120 species as valid. Applications of the following species names to forms previously recorded from Japanese waters are regarded as uncertain: Amphiporus cervicalis, Amphiporus depressus, Amphiporus lactifloreus, Cephalothrix filiformis, Cephalothrix linearis, Cerebratulus fuscus, Lineus vegetus, Lineus bilineatus, Lineus gesserensis, Lineus grubei, Lineus longifissus, Lineus mcintoshii, Nipponnemertes pulchra, Oerstedia venusta, Prostoma graecense, and Prostoma grande. The identities of the taxa referred to by the following four nominal species require clarification through future investigations: Cosmocephala japonica, Dicelis rubra, Dichilus obscurus, and Nareda serpentina. The nominal species established from Japanese waters are tabulated. In addition, a brief history of taxonomic research on Japanese nemerteans is reviewed.

著者

Kakui Keiichi Hiruta Chizue

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.39, no.1, 2022-02

被引用文献数

6

---

We describe a new typhlotanaid species, Hamatipeda kohtsukai sp. nov., collected from between 167 and 488 m depth in the Sagami Sea, Japan. This is the first record of Hamatipeda from the northern hemisphere. Hamatipeda kohtsukai resembles Hamatipeda trapezoida from the Subantarctic region in having pereonites 1–3 widest anteriorly (not rectangular), but differs from it in the length ratio of antennal articles 4/5; the number of setae on the dactyli of pereopods 1–3, ischia of pereopods 4–6, and carpi of pereopods 4–6; the shape of the unguis of pereopods 4–6; and the shape of the uropodal endopod. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA (18S) genes in H. kohtsukai. A phylogenetic reconstruction based on the 18S sequences recovered a highly supported Typhlotanaidae clade containing H. kohtsukai and Typhlotanais mixtus, with Paranarthrura sp. (Agathotanaidae) as the sister taxon. A key to species of Hamatipeda is presented.

著者

Shimada Daisuke Kakui Keiichi

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.39, no.1, 2022-02

被引用文献数

1

---

We describe three free-living marine nematode species from Sagami Bay, Japan. Wiesoncholaimus jambio sp. nov. is the second species of this genus. It differs from the type species, Wiesoncholaimus mawsonae Inglis, 1966, by its dorsal tooth, which is as long as the other two teeth; its conicocylindrical tail, which is as long as 4.6–4.8 cloacal body diameters; and the absence of the gubernaculum. Thalassironus cf. britannicus de Man, 1889 agrees well with a redescription of Thalassironus britannicus de Man, 1889 based on specimens collected near the type locality. However, as it is possible that T. britannicus sensu lato includes two or more species, our species may not be conspecific to T. britannicus sensu stricto. Vasostoma cf. longispicula Huang and Wu, 2010 closely resembles Vasostoma longispicula Huang and Wu, 2010 originally described from China, but minor differentiations are observed in body diameter, body cuticle thickness, and type of precloacal supplements.

著者

Kakui Keiichi Kano Yasunori

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.38, no.3, pp.267-272, 2021-06

被引用文献数

3

---

We present a complete mitochondrial genomic sequence for the tanaidacean Arctotanais alascensis (Richardson, 1899); this is the first complete mitogenome reported from the order Tanaidacea. The mitogenome is 13,988 bp long and contains 13 protein coding and two ribosomal RNA genes (as is typical for animal mitogenomes), and 21 of 22 transfer RNAs; we did not detect an isoleucine transfer RNA (trnI) gene. The gene order differed markedly from the hypothetical ground pattern for Pancrustacea; only four clusters (trnM + nad2; trnC + trnY + cox1 + trnL2 + cox2; trnD + atp8 + atp6 + cox3; trnH + nad4 + nad4l) ancestrally present were retained. In a malacostracan phylogenetic tree reconstructed from mitogenome data, basal relationships were marginally supported or incongruent with the traditional morphology-based classification and the latest phylogenetic reconstructions from large transcriptomic datasets. Relationships involving more recent divergences were better supported in our tree, suggesting that complete mitogenome sequences are more suitable for phylogenetic analyses within malacostracan orders, presumably including Tanaidacea.

著者

Suga Hiromu Hirano Wataru Katoh Toru Matsubayashi Kei W. Katakura Haruo

出版者

Zoological Society of Japan

雑誌

Zoological science (ISSN:02890003)

巻号頁・発行日

vol.33, no.6, pp.603-610, 2016-12

被引用文献数

3

---

The ladybird beetles Propylea quatuordecimpunctata and P. japonica have largely overlapping distributions in northern Japan, and in the laboratory produce fertile hybrids. In this study, we surveyed the distribution and morphological differentiation of these species and the hybrids in natural populations, with a focus on western Hokkaido, northern Japan. Phenotypic analyses were conducted for 987 individuals collected at 90 localities. In addition, the nuclear internal transcribed spacer-II (ITS2) region (549 bp) and part of the mitochondrial cytochrome c oxidase subunit I (COI) gene (700 bp) were sequenced for 620 individuals from 53 localities. Analyses of both phenotypic and genotypic features discriminated two distinct entities assignable to P. quatuordecimpunctataand P. japonica. However, individuals with intermediate phenotypes and/or genotypes also occurred extensively, indicating natural hybridization. Putative P. quatuordecimpunctata individuals were collected across a wide range of altitudes (30-600 m), whereas those of P. japonica were found mostly lower than 300 m alt. In addition, P. quatuordecimpunctata was dominant in semi-open habitats shaded by canopy foliage, whereas P. japonica was frequent in more open habitats. The perceived altitudinal difference in the distributions may thus in part be a consequence of this different habitat preference, as open habitats are more common at lower altitudes in the study area.

著者

Nishi Hirotaka Sota Teiji

出版者

日本動物学会

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.24, no.5, pp.475-485, 2007-05

---

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

Chikamoto Kyoko Kagaya Katsushi Takahata Masakazu

出版者

Zoological Society of Japan

雑誌

Zoological Science (ISSN:02890003)

巻号頁・発行日

vol.25, no.8, pp.783-792, 2008-08

被引用文献数

11

---

Crayfish initiate walking behavior not only reflexively in response to external stimuli but also spontaneously in the absence of any specific stimulus. In order to analyze the initiation mechanism underlying these different types of walking, we made simultaneous electromyographic (EMG) recordings from thoracic legs when animals initiated walking, either reflexively or spontaneously, and video recorded their movements synchronously with the EMG recording. Two different stimuli, mechanical and chemical, were used to reflexively induce walking. A non-rhythmic, sustained activation of leg muscles was found to precede the behavioral initiation of either type of walking. The duration of this non-rhythmic muscle activation was significantly longer in the spontaneously initiated walking than in the mechanical stimulus-evoked walking, although no difference was observed between the spontaneous and chemical stimulus-evoked walking. EMG recordings from all eight legs revealed that their non-rhythmic muscle activation occurred almost simultaneously prior to initiation of rhythmical stepping movements. When an animal was suspended without a leg substratum, the timing of muscle activation was more variable among the legs than in the free condition on the substratum. When the circumesophageal commissures were both severed to eliminate signals descending from the brain to the thoracic ganglia, the bilaterally coordinated rhythmic burst activity was not observed in the walking legs. These findings suggest that the spontaneous initiation of walking behavior requires sensory feedback signals from leg proprioceptors, subserved by a different descending activation mechanism from that for stimulus-driven initiation of walking.