著者

Keiichi Kakui Tomoyuki Komai

出版者

Aquos Institute

雑誌

水生動物 (ISSN:24348643)

巻号頁・発行日

vol.2022, pp.AA2022-1, 2022 (Released:2022-01-30)

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We report the first occurrence record of the freshwater ectoparasitic platyhelminth Scutariella japonica (Matjašič, 1990) from Hokkaido, Japan. The flatworms were collected from the surface of exoskeleton and the inside of branchial chamber of the atyid shrimp Neocaridina sp. aff. davidi. Phylogenetic analysis based on the 18S + 28S concatenated dataset of rhabdocoel flatworms retrieved the Scutariella clade, and our specimens identified with Scutariella japonica were genetically distinct from those referred to S. sinensis Chen, Feng, Lin, Lu & Wang, 2018. Phylogenetic analyses using COI showed that the host shrimp specimens from Sapporo were clustered with N. koreana identified by Shih et al. (2017) and placed close to N. palmata (Shen, 1948) and N. davidi (Bouvier, 1904). Our specimens did not agree with the original description of N. koreana Kubo, 1938, particularly in the shape of the endopod of the male pleopod 1. The identity of the present host shrimp specimens could not be established satisfactorily, and thus they were referred to N. sp. aff. davidi for the time being.

著者

Keiichi Kakui Michitaka Shimomura Shoichi Kimura Taeko Kimura

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.24, no.1, pp.103-108, 2019-05-25 (Released:2019-05-25)

参考文献数

25

被引用文献数

1

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In 2017, we collected a pair (male and female) of topotypic individuals of the parasitic isopod Pseudione nephropsi Shiino, 1951 from a single nephropid lobster, Metanephrops japonicus (Tapparone-Canefri, 1873), at 310–298 m depth off the eastern coast of the Kii Peninsula, Japan. Based on these specimens, we provide a supplementary description of the male and female morphology, and present mitochondrial cytochrome c oxidase subunit I (COI) DNA barcode sequences. The sequence length amplified with primer pair LCO-1490/HCO-2198 was 658 nt, and there were four synonymous nucleotide substitutions (0.6% p-distance) between the two sequences.

著者

Yushi Hosoda Shinri Tomioka Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.23, no.2, pp.215-218, 2018-11-25 (Released:2018-11-25)

参考文献数

12

被引用文献数

1

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We report the first record of the ammotheid pycnogonid species Hemichela nanhaiensis Wang et al., 2015, from Japanese waters. Four specimens of H. nanhaiensis were collected from the East China Sea at depths of 405–635 m, including the first females ever found. We redescribe male and female H. nanhaiensis from these specimens. We found that H. nanhaiensis is sexually dimorphic in the number of tiny lateral outgrowths on the lateral processes; length of the lateral process tubercles and oviger articles 4 and 5; ratio of the terminal claw to article 10 in the oviger; presence or absence of a proximal reversed spine on oviger article 5; thickness of the leg femur; and number of gonopores.

著者

Masanori Nonaka Nozomi Hanahara Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.2, pp.231-243, 2023-11-09 (Released:2023-11-09)

参考文献数

28

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A new species of Hemicorallium Gray, 1867 (Coralliidae), Hemicorallium meraboshi sp. nov., is described here. The specimen was found at a depth of 1744–1755 m, approximately 340 km east of the Honshu (mainland Japan) coast. The colony was identified by visual and microscopic observation of standard morphological characteristics (colony size, diameters of colony base and branches, diameter and height of autozooid mound, thickness of coenenchyme, sclerite sizes, etc.) along with support from molecular evidence. The unique features of this specimen are the large (more than 2 mm in diameter) autozooid mounds and the sizable sclerites in the coenenchyme (over 0.1 mm long) that are 8-radiates and multi-radiates predominantly. This new species is the northernmost record of Pacific precious corals.

著者

Keiichi Kakui Daisuke Uyeno Tohru Naruse

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.24, no.1, pp.49-60, 2019-05-25 (Released:2019-05-25)

参考文献数

40

被引用文献数

1

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We describe Parakonarus kajii sp. nov. from near Iriomote Island, Ryukyu Islands, southwestern Japan. This is the first record of Parakonarus from the North Pacific. As members in this genus show great sexual dimorphism, we checked our male and female specimens for conspecificity by using partial sequences of the cytochrome c oxidase subunit I (COI) gene. The two individuals differed by two nucleotide substitutions in 661 nt (0.3% K2P distance), indicating they are the same species. This species closely resembles P. kopure reported from New Zealand, but differs in having the ventral process on the chelipedal carpus longer than wide, the inner comb-row on the chelipedal propodus composed of 16 setae, and the dactylus and unguis of pereopods 4–6 fused in the male; and the carpi of pereopods 2 and 3 without a ventrodistal spiniform seta, the propodal palm of the cheliped with two inner simple setae at the insertion of the dactylus, and article 2 of the maxillipedal palp with one mid-outer and one outer distal simple setae in the female. On the inner surface of the chelipeds in male P. kajii, we observed an elongate plate-like structure that could be a reduced ischium.

著者

Yuki Tanabe Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.24, no.2, pp.181-187, 2019-09-25 (Released:2019-09-25)

参考文献数

14

被引用文献数

1

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We describe Teleotanais madara sp. nov. from the surfaces of mangrove roots on mudflats at Iriomote Island, Ryukyu Islands, southwestern Japan. This is the first record of any teleotanaid species from the northwestern Pacific. Teleotanais madara resembles T. gerlachi and T. gerlachi sensu Sieg (1976), but differs in having a mid-inner simple seta on antennular article 2, two ventral setae on the basal article of the uropod, the chelipedal fixed finger with one or two ventral simple setae, ventrodistal simple setae on the perepod-1 merus being half as long as the width of the merus, and the dactylus–unguis of pereopods 4–6 articulate. We also present the nucleotide sequence for part of the cytochrome c oxidase subunit I (COI) gene in T. madara for future use in DNA barcoding and phylogeny.

著者

Keiichi Kakui Shinri Tomioka

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.23, no.1, pp.61-68, 2018-05-25 (Released:2018-05-26)

参考文献数

22

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We establish the new anarthrurid genus Tsuranarthrura gen. nov. based on the new species T. shinsei sp. nov. collected from 1890 m depth off the eastern coast of Japan, northwestern Pacific Ocean. Tsuranarthrura gen. nov. is the third paratanaoid genus with members having a fused segment composed of pereonite 6 and the pleon, a character state previously restricted to the genera Coalecerotanais Larsen, 2003 (Family incertae sedis) and Metagathotanais Bird and Holdich, 1988 (Family Agathotanaidae). Among anarthrurid genera, Tsuranarthrura gen. nov. is similar to Anarthrura Sars, 1882, Anarthrurella Bird, 2004, and Crenicarpus Drumm and Bird, 2016 in having the labrum not laterally compressed and the antenna with naked fourth and fifth articles from the distal end. However it differs from the latter three in having pereonite 6 fused with the pleon, the maxillipedal endite with a distal seta, the chelipedal merus with a ventral simple seta, and the merus naked on pereopods 2 and 3. We also present the nucleotide sequence for part of the cytochrome c oxidase subunit I (COI) gene in T. shinsei for future use in DNA barcoding or phylogeny.

著者

Daisuke Shimada Atsushi C. Suzuki Megumu Tsujimoto Satoshi Imura Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.26, no.1, pp.49-63, 2021-03-22 (Released:2021-03-22)

参考文献数

81

被引用文献数

4

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Two new species of free-living marine nematodes, Odontophora odontophoroides sp. nov. and Parabathylaimus jare sp. nov., are described from the coastal sand of Langhovde, Lützow-Holm Bay, Dronning Maud Land, Antarctica. Odontophora odontophoroides sp. nov. is the only species in Odontophora Bütschli, 1874 that has bicuspidate odontia. Odontophora odontophoroides sp. nov. is similar to species in Odontophoroides Boucher and Helléouët, 1977 and Synodontium Cobb, 1920 in having bicuspidate odontia, but differs in having a didelphic reproductive system in females. Parabathylaimus jare sp. nov. differs from congeners in the unjointed inner labial and cephalic sensilla, the outer labial sensilla three-jointed in males and two-jointed in females, the position of the amphids, the shorter spicules, and the conical tail without long subterminal setae. Modified generic diagnoses and keys to species are included for Odontophora and Parabathylaimus De Coninck and Schuurmans Stekhoven, 1933. A new combination, Parabathylaimus arthropappus (Wieser and Hopper, 1967) comb. nov., is established.

著者

Daisuke Shimada Atsushi C. Suzuki Megumu Tsujimoto Satoshi Imura Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.22, no.2, pp.151-159, 2017-11-25 (Released:2017-12-05)

参考文献数

61

被引用文献数

5

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A new species of free-living marine nematode, Oncholaimus langhovdensis sp. nov., is described from the intertidal zone of Langhovde (near Syowa Station), Dronning Maud Land, East Antarctica. It closely resembles 11 congeners in the conico-cylindrical tail shape present in males and amphid and excretory pore positions, short spicules, and Demanian system structure present in females. However, it mainly differs from these congeners in body size, de Man’s ratios, tail length and shape, and Demanian system structure present in females. Oncholaimus langhovdensis sp. nov. also resembles four congeners known only by females, but it can be distinguished from them based on the tail length and uvette position. In addition to O. langhovdensis sp. nov., two undescribed species (Tripyloididae gen. sp. and Axonolaimidae gen. sp.) and four unidentified species (Sphaerolaimus sp., Oncholaimidae gen. sp., Comesomatidae gen. sp., and Chromadorida fam. gen. sp.) were found from the same locality.

著者

Keiichi Kakui Takafumi Nakano

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.24, no.2, pp.179-180, 2019-07-25 (Released:2019-07-25)

参考文献数

15

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The genus-group name Curtipleon Bǎcescu, 1976 is not available due to Bǎcescu’s failure to fix its type species in the original publication. This genus-group name should be attributed to Sieg (1983)—the work accidentally validated the genus-group name under Article 13 of the International Code of Zoological Nomenclature.

著者

Yoshinobu Hayakawa Keiichi Kakui

出版者

Aquos Institute

雑誌

水生動物 (ISSN:24348643)

巻号頁・発行日

vol.2022, pp.AA2022-10, 2022-06-09 (Released:2022-06-09)

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We report microhabitats used by the tanaidid tanaidacean Zeuxo ezoensis Okamoto et al., 2020 on the marine alga Sargassum confusum C. Agardh, as well as its molting behavior, based on observation of captive individuals. Zeuxo ezoensis constructed its tube-shaped nests on S. confusum (1) at the bases of lateral branches, (2) on main branches in the apical region, (3) in cracked air bladders, and (4) in clumps of a filamentous alga (Chordariaceae sp.) epiphytic on S. confusum. The behavioral sequence of a single molt observed for a male Z. ezoensis was as follows. (1) A break occurred along the ventrolateral and posterodorsal edges of the carapace, creating a dorsal opening in the old exoskeleton; (2) the animal began to extricate itself from the old exoskeleton through this opening; (3) the cephalothorax and its appendages shed the old exoskeleton; and (4) the animal completed extrication from the old exoskeleton. The entire molt took about five minutes.

著者

Daisuke Shimada Keiichi Kakui

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.25, no.2, pp.205-211, 2020-09-18 (Released:2020-09-18)

参考文献数

30

被引用文献数

1

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A new species of free-living marine nematode, Proplatycoma tsukubae sp. nov. (Enoplida: Leptosomatidae: Platycominae), is described from Japan. The specimens were obtained from sea-floor sediments collected at a depth of 117–202 m off the coast of Shimoda, Shizuoka Prefecture, Japan. Proplatycoma tsukubae sp. nov. is similar to P. africana (Gerlach, 1959) in the unilobed amphidial flaps. However, it differs from P. africana based on the much shorter amphidial flaps just reaching the anterior edge of the amphidial aperture, the accessory structure of the spicules being constricted at the middle and tapering toward both ends, the longer apophyses of the gubernaculum, and the blunt tip of the tail. The partial nucleotide sequences for the cytochrome c oxidase subunit I and the 18S rRNA regions in P. tsukubae sp. nov. are also presented for future applications in DNA barcoding or phylogenetic studies. Updated taxonomic keys to genera in the subfamily Platycominae and species in Proplatycoma are provided.