著者

Itaru Kobayashi Toshihiko Fujita

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.28, no.1, pp.45-50, 2023-01-26 (Released:2023-01-26)

参考文献数

9

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A new shallow-water species of the genus Odontohenricia Rowe and Albertson, 1988 is described from the coast of Rishiri Island, Hokkaido, northeastern Japan. The new species is different from other congeners in having intermarginal series extending 2/3 of the arm length, abactinal spines more than 0.3 mm in length, and oral spines with opaque and serrated tips.

著者

Itaru Kobayashi Masaki Yamamoto Yoshihiro Fujiwara Shinji Tsuchida Toshihiko Fujita

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.27, no.2, pp.251-258, 2022-07-29 (Released:2022-07-29)

参考文献数

16

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We describe a new species of the rare and deep-sea family Myxasteridae from Japanese waters. This is the first record of this family in the western North Pacific. The new species, Asthenactis agni n. sp., differs from all congeners in having seven arms with an R/r ratio of 7.2, primary radial plates with convex distal edges, and two to three actinolateral spines that are up to 4.7 mm long.

著者

Alexandr N. Mironov Toshihiko Fujita

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.101-110, 2021-03-22 (Released:2021-03-22)

参考文献数

31

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Hirsutocrinus duplex, a new genus and new species of the Bathycrinidae, collected from Okinawa, Japan at a depth of 596–606 m, is described. The main diagnostic characters of the new genus are the presence of side plates in pinnules and of knobby processes on Brs 1–2. Knobby processes on secundibrachials are found for the first time. Monachocrinus A. H. Clark, 1913 shares side plates with Hirsutocrinus. It differs from the new genus in having knobby processes on IBrs 1, parallel ridges on the articular surface of knobby processes, proximal and distal arm pattern a b+c d+e f, saccules, in lacking knobby processes on IBrs 2 and Brs 1–2, pinnule on every second Br, x-shaped tube-feet plates, needle-like spines on external surface of IBrs and Brs. The cover and side plates are similar to each other in Monachocrinus, and quite different in Hirsutocrinus. Hirsutocrinus duplex is the shallowest species in the abyssal family Bathycrinidae usually known from 1100 to 9735 m. Other than H. duplex, only three among 25 nominal bathycrinid species are known from depths less than 1000 m.

著者

Mikihito Arai Toshihiko Fujita

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.7-21, 2021-01-01 (Released:2021-01-01)

参考文献数

44

被引用文献数

1

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Five species of sea stars of the families Ophidiasteridae and Goniasteridae including two new species, Bathyferdina caelator sp. nov. and Fromia labeosa sp. nov., were collected by dredging from the mesophotic zone of the Ogasawara Islands, Japan. Bathyferdina caelator is distinguished from B. aireyae Mah, 2017 by the presence of glassy bosses (crystal bodies) on actinal and adambulacral plates and the absence of them on marginal plates. Fromia labeosa has large, elliptical pedicellariae on the actinal plate and is further distinguished from its congeners based on characters of the abactinal and superomarginal plates, granules, actinal papulae, furrow spines, and the subambulacral spines. We also provide descriptions for three mesophotic species, Fromia eusticha Fisher, 1913, Ogmaster capella (Müller and Troschel, 1842), and Tamaria tenella (Fisher, 1906), which are poorly studied in Japanese waters.

著者

Daiki Wakita Toshihiko Fujita Hiroshi Kajihara

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.119-135, 2019-07-25 (Released:2019-07-25)

参考文献数

46

被引用文献数

4

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The subgenus Setihenricia Chichvarkhin and Chichvarkhina, 2017 currently consists of 32 out of 94 species of sea stars in the genus Henricia Gray, 1840. However, only 10 have been molecularly ascertained as to the phylogenetic position. Based on seven mitochondrial gene markers (16S rRNA, COI, tRNA-Ala, tRNA-Leu, tRNA-Asn, tRNA-Gln, and tRNA-Pro), we performed molecular analyses to assess the monophyly of Setihenricia using 16 species of Henricia from Japanese waters, as well as other congeners for which sequences were available in public databases. The monophyletic Setihenricia was only weakly recovered because the support values were low, but we assume this taxon may be valid in consideration of a morphological key. Henricia kinkasana Hayashi, 1940 is herein identified as a new member of Setihenricia, based on molecular and morphological evidence. Sequences in the public databases previously identified as H. compacta (Sladen, 1889) and H. obesa (Sladen, 1889) were nested in the Setihenricia clade; these two species are also likely members of Setihenricia. Our morphological assessment yielded three findings: (1) the number of the rows of spines on each inferomarginal plate, being three or more, appears to be a useful diagnostic character for Setihenricia, as has been suggested in previous studies, (2) the degree of spine tapering turned out to be less relevant in diagnosing the subgenus than previously supposed, (3) two newly introduced characters—(i) the width of adambulacral plates and (ii) the ratio of two measurements in ambulacral plates to the length of interradius—may be effective to distinguish members of this apparent Henricia subclade from other members of the genus.

著者

Sau Pinn Woo Hiroshi Kajihara Nozomu Iwasaki Toshihiko Fujita

出版者

日本動物分類学会

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.22, no.1, pp.45-52, 2017-05-25 (Released:2017-05-25)

参考文献数

12

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The sea cucumber, Holothuria (Cystipus) dura Cherbonnier and Féral, 1981, previously known only from the Philippines and New Caledonia, is newly recorded from Japanese waters; this is also the first record of the subgenus Cystipus from Japan. The two specimens described here were collected from the sublittoral bottoms near Hahajima island (126–261 m depth) and Okinoshima island (100–120 m depth). The morphology of the Japanese specimens is briefly described. In-situ photographs of the living individuals and scanning electron micrographs (SEM) of ossicles are provided for the first time for this species. The table ossicles in the dorsal body and in the papillae are highly modified fenestrated spheroids that have not been depicted previously. Some of the ventrolateral conical papillae, especially those in the middle part of the body, were bifurcated, perhaps indicative of increased surface area against the bottom for powerful propulsion while ‘walking’. Some notes on locomotion are given, inferred from the in-situ photographs and the morphology of the ventrolateral conical papillae.