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

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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

Kakui Keiichi Fujita Yoshihisa

出版者

Cambridge University Press

雑誌

Journal of the Marine Biological Association of the United Kingdom (ISSN:00253154)

巻号頁・発行日

vol.103, 2023

被引用文献数

1

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We describe a new sea spider species, Pantopipetta hosodai sp. nov., based on one juvenile female collected from a submarine cave ('Akumanoyakata' Cave) in Shimojijima Island, Miyako Island Group, Ryukyu Islands, southwestern Japan. It was collected from the second slope zone of the cave, 80-100 m from the entrance, no light, low salinity and with rocky substrate. This is the first record globally of a Pantopipetta species from a submarine cave and anchialine environment. Pantopipetta hosodai sp. nov. resembles Pantopipetta auxiliata, Pantopipetta lenis and Pantopipetta oculata in having auxiliary claws, but differs from them in having a palp with three short distal articles, lateral processes without dorsodistal tubercles, coxae 1 and 3 of legs 1-3 each with one long dorsal tubercle and one dorsodistal tubercle bearing a seta on each femur. Features of the palp appear to delineate two species groups in Pantopipetta, i.e. (1) those having four small distal articles, and a small, basal palp article between the lateral cephalon process and longest palp article (eight-articulate palp) and (2) those having three small distal articles, and lacking the small basal article (six-articulate palp), but further detail examination of the described species is needed. We discuss the diagnostic characters separating Pantopipetta and Austrodecus and the generic affiliation of Austrodecus aconae. Few pycnogonids from marine or anchialine caves have been identified to species, and it is generally unknown whether cave-dwelling pycnogonids tend to be troglobites.

著者

Matsumoto Yu Kajihara Hiroshi Kakui Keiichi

出版者

Sociedade Brasileira de Carcinologia

雑誌

Nauplius (ISSN:23582936)

巻号頁・発行日

vol.31, pp.e2023005, 2023

被引用文献数

1

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A new podocerid amphipod, Leipsuropus seisuiae sp. nov., from 338-340 m depth in the Kumano Sea, Japan, Northwestern Pacific, is described. This is the deepest record of any Leipsuropus species. Leipsuropus seisuiae sp. nov. is distinguished from four other congeneric species in having: i) pereonites 2-5 each with five narrow spiniform projections on tergal plate, ii) one dorsal tubercle on the telson, and iii) one small, proximal, denticulate projection on gnathopod-2 palmar margin. A key to males of the species of Leipsuropus is provided.

著者

Kakui Keiichi Fukuchi Jun Shimada Daisuke

出版者

Springer

雑誌

Parasitology Research (ISSN:09320113)

巻号頁・発行日

vol.120, no.6, pp.2357-2362, 2021-06

被引用文献数

7

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Nectonema, the only horsehair worm (Nematomorpha) genus found in marine environments, was previously known to be parasitic only in decapod crustaceans. We report Nectonema sp. as the first record of a marine nematomorph parasitic in isopod crustaceans. This is also the third record of marine nematomorphs from the North Pacific. Six infected isopods (Natatolana japonensis) collected from 1425 m of depth in the Sea of Japan each contained one to seven (mean 2.33) nematomorphs in the body cavity in the pereon. There was no correlation between the host body length and number of parasites. For Nectonema sp., we describe and illustrate morphological features of the parasitic juvenile stage and present nucleotide sequences for the cytochrome c oxidase subunit I gene (COI or cox1; 451 nt), 18S rRNA gene (1777 nt), and region spanning the internal transcribed spacer 1 (ITS1) and the 28S rRNA gene including the 5.8S rRNA gene and ITS2 (1218 nt in total). In an 18S maximum-likelihood tree that included 24 nematomorph species, Nectonema sp. grouped with N. agile from the northwestern Atlantic; the 18S gene from these two taxa was divergent by 11.8% K2P distance, suggesting that they are different species. Nectonema species may have a broader range of host groups than previously suspected, but may have been previously misidentified as nematode parasites.

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

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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

Hosoda Yushi Kakui Keiichi

出版者

Taylor & Francis

雑誌

Marine biology research (ISSN:17451000)

巻号頁・発行日

vol.16, no.5, pp.390-395, 2020-05

被引用文献数

3

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We describe a new pycnogonid species,Pantopipetta lenissp. nov., collected from 141-152 m depth in southern Japan, North Pacific Ocean.Pantopipetta lenisclosely resemblesPantopipetta auxiliataandPantopipetta oculatain having auxiliary claws on the legs, but differs from them in lacking dorsodistal tubercles on the lateral processes, having the first short distal article of palp shorter than combined length of the other three short distal articles, having one slight dorsal tubercle on the coxa 1 of legs, having a short dorsal tubercle on the coxa 3 of legs, and lacking a long dorsodistal tubercle on the femur of legs. The palp base (the short article-like structure proximal to the longest palp article) inP. lenisis articulated with the cephalon, i.e. it is actually an article. Although the palp base has been regarded as a lateral process of the cephalon, it is the first article of the palp inP. lenis.

著者

Kakui Keiichi Hiruta Chizue

出版者

John Wiley & Sons

雑誌

Journal of Morphology (ISSN:03622525)

巻号頁・発行日

vol.275, no.9, pp.1041-1052, 2014-09

被引用文献数

14

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Among arthropods, various insects, spiders, and crustaceans produce thread. The crustacean Tanaidacea include species that use thread mainly to construct dwelling tubes. While thread production was previously known only in Tanaoidea and Paratanaoidea, it was recently discovered in two species in Kalliapseudidae (Apseudoidea), although information on the morphology of the thread‐producing system was lacking. Using histology, light and scanning electron microscopy, we found that the kalliapseudid Phoxokalliapseudes tomiokaensis comb. nov. lacks the sort of glandular structures associated with thread production in the pereonites, but has these structures in pereopods 1–6. We observed four types of glandular systems defined by the types and distribution of glands they contain: Type A (pereopod 1), Type B (pereopods 2 and 3), Type C (pereopods 4 and 5), and Type D (pereopod 6). All types have small rosette glands and lobed glands; Type A additionally has large rosette glands. The inferred thread‐producing apparatus in P. tomiokaensis is very different from that in Tanaoidea and Paratanaoidea, suggesting that kalliapseudids evolved thread production independently from the latter two groups. J. Morphol. 275:1041–1052, 2014. © 2014 Wiley Periodicals, Inc.

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

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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

Kakui Keiichi Shimada Daisuke

出版者

Cambridge University Press

雑誌

Journal of Helminthology (ISSN:0022149X)

巻号頁・発行日

vol.96, pp.e33, 2022

被引用文献数

7

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We report the first mermithid nematode found to be parasitic in a marine tanaidacean crustacean. Ten host tanaidaceans were collected from 52 m depth in Otsuchi Bay, Iwate, Japan, northwestern Pacific, and identified as a species in the tanaidid genus Zeuxo Templeton, 1840. Nematodes occurred in the host’s body cavity; in one case, at least two individuals inhabited a single host. We provide a brief description and illustrations of the morphology of the nematode. In a phylogenetic reconstruction based on the 18S rRNA gene, the nematode nested in a clade otherwise containing mermithids from terrestrial or freshwater hosts, showing an expansion in host utilization in Mermithidae Braun, 1883 from terrestrial/freshwater hosts to a marine organism.

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

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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

Kakui Keiichi Nomaki Hidetaka Komatsu Hironori Fujiwara Yoshihiro

出版者

Oxford University Press

雑誌

Biological Journal of the Linnean Society (ISSN:00244066)

巻号頁・発行日

vol.131, no.3, pp.566-574, 2020

被引用文献数

5

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Information on the extent, diversity and connectivity of populations is lacking for most deep-sea invertebrates. Species of the order Tanaidacea (Crustacea), one of the most diverse and abundant macrofaunal groups in the deep sea, are benthic, lack a planktonic larval stage, and thus would be expected to have narrow distributional ranges. However, with molecular evidence from the COI gene, we show here that the deep-sea tanaidacean Carpoapseudes spinigena has a distributional range spanning at least 3700 km, from off northern Japan to the south-eastern Bering Sea. Living individuals found in a sediment core indicated that the species is a sedentary burrower. COI analyses revealed a low level of genetic diversity overall, and low differentiation (p-distance, 0.2–0.8%) between the Japan and Bering Sea populations. One hypothesis to explain the low genetic diversity over a broad region is that the Japan population was founded by individuals transported by ocean currents from the Bering Sea. However, due to limited data, other explanations cannot be ruled out. Our results indicate that continued sampling is of fundamental importance to understanding how genetic and taxonomic diversity originate and are maintained in the deep sea.

著者

Kakui Keiichi Munakata Mizuho Tanaka Hayato Hiruta Chizue

出版者

Elsevier

雑誌

Zoologischer Anzeiger (ISSN:00445231)

巻号頁・発行日

vol.293, pp.145-148, 2021-07

被引用文献数

1

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Ostracoda is a diverse group of tiny crustaceans. Although more than 9330 extant species have been described, whole-mitogenomic data were available for only five species. Here we present a complete mitogenomic sequence for an additional species, the parthenogenetic podocopan ostracod Heterocypris spadix. The mitogenome is 15,205 bp long and contains the typical animal mitogenomic complement of 13 protein coding, two ribosomal RNA, and 22 transfer RNA genes. In a mitogenome-based phylogenetic tree, Myodocopa and Podocopa were each monophyletic. Gene order in Podocopa was much more similar to the pancrustacean ground pattern than was gene order in Myodocopa. Gene order was invariant in the three myodocopan species examined, all in the family Cypridinidae. Within Podocopa, two species from different families (Fabaeformiscandona kushiroensis, Candonidae; H. spadix, Cyprididae) were identical in gene order and differed from the pancrustacean ground pattern by only a single recombination. In Cyprididae, however, Cypridopsis vidua differed from H. spadix by five rearrangements. These conflicting patterns—apparent gene-order conservation within (Cypridinidae) and between families (Cyprididae and Candonidae), but marked divergence within a family (Cyprididae)—suggest that the evolution of gene order in ostracods was more complex than that expected from the cypridinid data.

著者

Kakui Keiichi Shiraki Shoki

出版者

The Crustacean Society

雑誌

Journal of Crustacean Biology (ISSN:02780372)

巻号頁・発行日

vol.41, no.2, pp.ruab026, 2021-06

被引用文献数

1

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Morphological diversity of sound-producing structures has not been well investigated among members of superorder Peracarida. Presumptive stridulatory sound-producing organs have been reported in some amphipods and tanaidaceans, and sound production by these organs has been documented in two isopod species in Oniscidea and Sphaeromatidea. Here we describe three presumptive stridulatory organs in the paranthurid isopod Paranthura cf. japonica Richardson, 1909, the first case known in Cymothoida. One type, consisting of a scale-bearing knob on the posterolateral corner of a pereonite and the scale-bearing anterolateral corner of the succeeding pereonite, was found between two pairs of pereonites (1, 2 and 2, 3). A second type involves a serrated structure in the sub-posterolateral region of pereonites 1 and 2, with the sharp anterolateral margins of pereonites 2 and 3 appearing to provide corresponding plectra. The third type involves an extension bearing a pair of serrated structures on the posteroventral margin of pereonites 1 and 2; the anterior-ventrolateral edges of pereonites 2 and 3 appear to provide corresponding plectra. All three organs occurred in both sexes of P. cf. japonica. Our discovery of novel, presumptive stridulatory organs in an intertidal isopod indicates that much remains to be learned about the biology of even common peracarid species.

著者

Shiraki Shoki Shimomura Michitaka Kakui Keiichi

出版者

Pensoft Publishers

雑誌

Zoosystematics and Evolution (ISSN:14351935)

巻号頁・発行日

vol.98, no.1, pp.109-115, 2022-03-31

被引用文献数

1

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We describe a new paranthurid isopod genus and species, Deltanthura palpus gen. et sp. nov., collected from a depth of 805–852 m off the southern coast of Mie prefecture, Japan. Deltanthura is similar to Pseudanthura Richardson, 1911 in having a triangular pleotelson, acute mandible with a 3-articulate palp, a maxillipedal endite, and a tapering uropodal exopod, but differs in having eyes and neotenous characters (reduced pereonite 7 and pereopods 7 lacking). Deltanthura and four paranthurid genera (Califanthura Schultz, 1977, Colanthura Richardson, 1902, Cruranthura Thomson, 1946, and Cruregens Chilton, 1882) share neotenous characters, but in Deltanthura the mandible is acute, with a 3-articulate palp and maxillipedal endites are present. Califanthura minuta Kensley & Heard, 1991 may belong in Deltanthura as they share the triangular pleotelson and tapering uropodal exopod, but we refrain from transferring it to Deltanthura as its description lacks the other diagnostic characters of Deltanthura. We provide a revised key to all genera in Paranthuridae Menzies & Glynn, 1968.

著者

Munakata Mizuho Tanaka Hayato Kakui Keiichi

出版者

Pensoft Publishers

雑誌

Zoosystematics and Evolution (ISSN:14351935)

巻号頁・発行日

vol.98, no.1, pp.117-127, 2022-04-05

被引用文献数

2

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We describe the cypridoidean ostracod Cavernocypris hokkaiensis sp. nov. from riverbed sediments in an alpine stream at an elevation of ca. 1850 m in the Taisetsu Mountains, Hokkaido, Japan. This species differs from congeners in having (1) the outer surface of the carapace smooth, with sparse, tiny setae, but without shallow pits; (2) the carapace elongate rather than triangular in lateral view; (3) the antennula consisting of seven podomeres; (4) first palpal podomere of maxillula with five dorsodistal and one ventro-subdistal setae; (5) the fifth limb lacking setae b and d; and (6) the fifth limb lacking a vibratory plate. We provided the key to the Cavernocypris species. We determined partial sequences for the cytochrome c oxidase subunit I (COI; cox1) and 18S rRNA (18S) genes in C. hokkaiensis. Our sample contained only females, and we obtained a partial 16S rRNA sequence for the endosymbiotic bacterium Cardinium from C. hokkaiensis, indicating the possibility that this ostracod species reproduces parthenogenetically. Our field survey and observations of captive individuals suggested that C. hokkaiensis may be endemic to the Taisetsu Mountains, with a low population density, narrow distributional range, and slow maturation to sexual maturity.

著者

Homma Riko Uyeno Daisuke Kakui Keiichi

出版者

Elsevier

雑誌

Parasitology International (ISSN:13835769)

巻号頁・発行日

vol.78, pp.102135, 2020-10

被引用文献数

4

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Based on specimens from the gill cavities of one Platichthys stellatus individual collected in the Sea of Japan, we investigated the taxonomic status of the enigmatic caligid genus Pseudolepeophtheirus and its type species, Pseudolepeophtheirus longicauda. In a maximum likelihood (ML) tree based on 18S rRNA gene sequences, the sequence from our sample was nested in a well-supported Lepeophtheirus clade, along with the type species, confirming that Pseudolepeophtheirus should be considered a junior synonym of Lepeophtheirus; our morphological data support this synonymy. Although a previous study had synonymized Pseudolepeophtheirus longicauda with Lepeophtheirus parvicruris, we found that the former differs morphologically from the latter in having a short leg-4 exopod, with the articulation between the first and second segments not evident (the shape of the posterior striated membrane on the leg-2 intercoxal sclerite also differs between two species), and detected slight differences in 18S rRNA sequences between two taxa. We thus concluded that this synonymy is invalid, and reinstate Lepeophtheirus longicauda as a valid species. A ML analysis of COI sequences from Pl. stellatus (the host fish for both L. longicauda and L. parvicruris) showed the host species to comprise distinct northwestern- and northeastern-Pacific clades. Lepeophtheirus longicauda is distributed in the northwestern Pacific and L. parvicruris in the northeastern Pacific, indicating co-divergence of the two copepod species with the host lineages.

著者

Kakui Keiichi

出版者

Springer

雑誌

Species Diversity of Animals in Japan (ISSN:25095536)

巻号頁・発行日

pp.603-627, 2017

被引用文献数

7

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The order Tanaidacea is a group of benthic crustaceans, most of which are small, up to a few millimeters long. Tanaidaceans are distributed worldwide, with more than 1,200 described species. Following the first taxonomic paper on a Japanese tanaidacean in 1936, many researchers have studied their taxonomy, morphology, reproductive biology, or ecology in the waters around Japan. This chapter presents a brief introduction to tanaidaceans and then reviews what is known of their systematics (taxonomy and phylogeny), biology (including feeding habits, phenology, morphology, reproductive modes, parasites, predators), and ecology in Japan. The chapter ends with a summary and prospects for future research. The general conclusion is that tanaidaceans have been under-studied, both globally and within Japan; the 104 nominal species reported from around Japan and the 1,200 species reported globally likely represent a fraction of the actual diversity. The phylogeny of tanaidaceans is largely unresolved at all taxonomic levels. Recent, significant new discoveries dealing with herbivory, selfing, skin-digging activity in holothuroid hosts, possible sound production, and tube building suggest that much remains to be learned about their general biology.

著者

木村 妙子 木村 昭一 角井 敬知 波々伯部 夏美 倉持 利明 藤田 敏彦 小川 晟人 小林 格 自見 直人 岡西 政典 山口 悠 広瀬 雅人 吉川 晟弘 福地 順 下村 通誉 柏尾 翔 上野 大輔 藤原 恭司 成瀬 貫 櫛田 優花 喜瀬 浩輝 前川 陽一 中村 亨 奥村 順哉 田中 香月 Kimura Taeko Kimura Shoichi Kakui Keiichi Hookabe Natsumi Kuramochi Toshiaki Fujita Toshihiko Ogawa Akito Kobayashi Itaru Jimi Naoto Okanishi Masanori Yamaguchi Haruka Hirose Masato Yoshikawa Akihiro Fukuchi Jun Shimomura Michitaka Kashio Sho Uyeno Daisuke Fujiwara Kyoji Naruse Tohru Kushida Yuka Kise Hiroki Maekawa Yoichi Nakamura Toru Okumura Junya Tanaka Kazuki

出版者

三重大学大学院生物資源学研究科

雑誌

三重大学フィールド研究・技術年報 = Annals of Field Research and Technology Mie University (ISSN:13496824)

巻号頁・発行日

vol.17, pp.1-29, 2019-11

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Preliminary results of the deep-sea faunal survey conducted from the TR/V Seisui-maru of Mie University in April 2019 are presented. A total of 20 taxonomists and ecologists working on a wide variety of animal taxa participated in this survey. Surveyed areas included the Kumano Sea(off Mie Prefecture)and south of the Kii Strait(off Tanabe Bay, Wakayama Prefecture), at depths of 112-775 m. Sampling gears employed were beam trawl and biological dredge. The collection is represented by macrobenthos and meiobenthos from nine animal phyla, including echinoderms, arthropods, molluscans and annelids. The number of phyla occurring in each station varied from seven to eight. The station with most diverse fauna at the phylum level was St. 3B(south of the Kii Strait, 775-661 m depth, mud bottom).Meiofauna includes priapulids, nematodes and small arthropods such as copepods, tanaidaceans, amphipods, isopods and cumaceans. In addition to freeliving species, cnidarians symbiotic on a gastropod and an antipatharian, and crustaceans parasitic on a fi sh and sea urchins were also collected. Preliminary identifi cations are given for Asteroidea, Ophiuroidea, Holothuroidea, Crinoidea, Cyclopoida, Siphonostomatoida, Tanaidacea, Isopoda, Decapoda, Mollusca, polychaetes, Bryozoa, Cnidaria and Nemertea.

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

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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.