著者

Yusuke Yamana Hayato Tanaka Shu Nakachi

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.53-68, 2017-05-25 (Released:2017-05-25)

参考文献数

32

被引用文献数

3

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Three new sea cucumbers collected in the intertidal and subtidal zone of southern Japan, Taeniogyrus mijim sp. nov., Rowedota chippiru sp. nov., and R. motoshimaensis sp. nov., are described. All three species display a small body size (approximately 10–20 mm), light body colour (primarily a transparent solid colour), and a small number of digits in their tentacles (one pair or two). They are easily distinguished from each other and from other congeners by the number of digits and by ossicle size and shape. Among these species, the state of the tooth series on the inner margin of the wheel ossicles is an important defining feature, i.e., a continuous row in Taeniogyrus but interrupted by concavities in Rowedota. Also, each tooth is sharp in T. mijim, trapezoidal in R. chippiru, and semicircular in R. motoshimaensis. The number of teeth per radiant is 7–16 (means of 10–13 in different specimens) in T. mijim, 7–15 (means 9–12) in R. chippiru, and 8–21 (means 11–19) in R. motoshimaensis. Among these three new species, only R. chippiru has thick rod ossicles in the body wall.

著者

Yusuke Yamana Hayato Tanaka Isao Hirabayashi Ichinosuke Dan Atsushi Hirai Akito Ogawa

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.27, no.1, pp.139-158, 2022-04-22 (Released:2022-04-22)

参考文献数

43

被引用文献数

1

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Three infaunal apodid sea cucumbers collected in Kushimoto, Shirahama, and Susami, in the southern coast of Wakayama, Japan are described. They have different morphological characteristics in body color, ossicle arrangement, and internal organs, each other. First species, animal displays a large body size (approximately 70–150 mm) and pale body color (semi-transparent pink with anterior tip brownish) was found out. Second species, animal displays a small body size (approximately 20 mm) and pale body color (transparent yellow) with whitish wheel-papillae on three dorsal interradii was found out. Third species, animal displays a moderate body size (approximately 20–35 mm) and deep red or reddish brown body color with dark yellowish wheel-papillae on three dorsal interradii was found out. All three species having 10 tentacles, sigmoid-hook ossicles, and wheel ossicles in their body wall, turned out to be belonging to the genus Taeniogyrus Semper, 1867, and new to science.

著者

Hayato Tanaka Susumu Ohtsuka

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.217-228, 2019-10-25 (Released:2019-10-25)

参考文献数

35

被引用文献数

1

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In the present study, we describe two new marine species, Microloxoconcha toyoshioae n. sp. and M. sublittoralis n. sp., collected from the sandy bottom in the western part of Japan, from the depths of approximately 20 to 30 m and 50 m, respectively. This represents the first record of this genus from such depths, since all 10 previously described species are known from the beach interstitial waters. We suspect the two new species are most probably also inhabiting spaces between sand grains since they have very small body and have been collected with other common interstitial ostracods belonging to Cobanocythere Hartmann, 1959; Parvocythere Hartmann, 1959; Paracobanocythere Gottwald, 1983; Parapolycope Klie, 1936; and Psammocythere Klie, 1936. Owing to their small body and fragile carapace, previous studies might have overlooked the existence of interstitial ostracods from habitats other than beach interstitial. In addition, a key to all species of the genus Microloxoconcha is provided.

著者

Shinnosuke Yamada Hayato Tanaka

出版者

The Japanese Society of Systematic Zoology

雑誌

Species Diversity (ISSN:13421670)

巻号頁・発行日

vol.16, no.1-2, pp.49-63, 2011-04-30 (Released:2018-03-30)

参考文献数

30

被引用文献数

5 7

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A new species of ostracod, Semicytherura sagittiformis sp. nov., is described from a sandy beach in Shizuoka Prefecture, central Japan. It lives in pore-waters of marine sandy sediments and is ecologically associated with other interstitial ostracods (e.g., Parapolycope and Microloxoconcha). Semicytherura sagittiformis is one of the smallest species in the genus Semicytherura, and its carapace size is comparable with those of some large interstitial ostracods. This fact suggests that a small carapace is the most important character for adaptation of ostracods to an interstitial environment.

著者

Yusuke Yamana Hayato Tanaka

出版者

日本プランクトン学会、日本ベントス学会

雑誌

Plankton and Benthos Research (ISSN:18808247)

巻号頁・発行日

vol.12, no.2, pp.83-94, 2017-05-30 (Released:2017-06-06)

参考文献数

32

被引用文献数

2

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Two new taeniogyrinid sea cucumbers collected in the intertidal zone of southern Japan, Taeniogyrus verruculosus sp. nov. and Scoliorhapis sesokoensis sp. nov. are described. Both species possess a small body size (approximately 30–40 mm), light body color (translucent white in preserved specimens), ten tentacles, and numerous verrucous surfaces on the body, within which small (mostly less than 70 µm in length) sigmoid-hook ossicles are present. The two new species have a very similar external appearance to each other, however they do differ in the number of tentacle digits: T. verruculosus possesses up to eight digits, whereas S. sesokoensis possesses up to six. In both species, wheel papillae are not present. T. verruculosus possesses only a few small (mostly less than 30 µm in diameter) wheel ossicles in the anterior dorsal skin, which are not present in S. sesokoensis. Additionally, the DNA barcode sequences of two new species were determined and are available in the DDBJ/NCBI/GenBank databases under the accession numbers.