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
1

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
Hisanori Kohtsuka Kohei Oguchi Yusuke Yamana Masanori Okanishi
出版者
The Plankton Society of Japan, The Japanese Association of Benthology
雑誌
Plankton and Benthos Research (ISSN:18808247)
巻号頁・発行日
vol.16, no.3, pp.228-236, 2021-08-06 (Released:2021-07-31)
参考文献数
60

More than 100 individuals of sea cucumber larvae were collected in the Japanese coastal sea of Moroiso, Sagami Bay, Kanagawa Prefecture, central-eastern Japan, in January 2018. Based on an obtained sequence of mitochondrial 16S rRNA gene region of one juvenile, it was identified as Sclerodactyla multipes by BLAST search with 0.3% genetic distance. The developmental process of the S. multipes was observed for three months, in which time, they grew from 250 µm to about 4 mm in length; here they showed distinct tentacles and dermal ossicles. Detailed morphological features of this species were described based on stereomicroscopic, fluorescence and SEM observations for the first time. This is the first description of life history through planktonic larva to juveniles in the family Sclerodactylidae.
著者
Yusuke Yamana Taiga Kunishima Masami Obuchi Takuma Fujii
出版者
The Plankton Society of Japan, The Japanese Association of Benthology
雑誌
Plankton and Benthos Research (ISSN:18808247)
巻号頁・発行日
vol.15, no.2, pp.168-177, 2020-05-27 (Released:2020-05-30)
参考文献数
11
被引用文献数
2

With a focus on building an inventory of subtropical species of epifaunal holothurians and completing an environmental assessment, SCUBA surveys were carried out in the Amami Islands of Kagoshima Prefecture in southern Japan. The following 12 nominal species belonging to seven genera (subgenera), as well as two as yet undescribed species belonging to two genera, were observed: Bohadschia argus Jäger, 1833; B. bivittata Mitsukuri, 1912; B. vitiensis (Semper, 1867); Holothuria (Halodeima) atra Jäger, 1833; H.(H.) edulis Lesson, 1830; Holothuria (Microthele) nobilis (Selenka, 1867); Personothuria graeffei (Semper, 1867); Stichopus chloronotus Brandt, 1835; S. hermanni Semper, 1867; S. naso Semper, 1867; Thelenota anax H.L. Clark, 1921; Euapta sp.; Synapta maculata (Chamisso et Eysenhardt, 1821); and Opheodesoma sp. In the semi-closed waters around the Amami Islands, epifaunal holothurians showed what seemed to be species-specific distribution patterns related to topographical features. Furthermore, ignition loss values of feces and sediments suggested that selective deposit feeding may be predominant in at least several of the species sampled.
著者
Yusuke Yamana Yuzo Ota Hisanori Kohtsuka Kazumi Yoshizaki
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.227-236, 2020-10-16 (Released:2020-10-16)
参考文献数
17

A new dendrochirotid sea cucumber, Massinium japonicum sp. nov., is described from areas in western Japan, including the middle of the Seto Inland Sea, west of the Sea of Japan, the shore of the Amakusa Peninsula, and the shore of the Kii Peninsula. The ossicle assemblage of the new species (M. japonicum) is similar to that of M. maculosum Samyn and Thandar, 2003, the type species of Massinium Samyn and Thandar, 2003. However, the new species is readily distinguishable from M. maculosum and its congeners by the absence of rod/elongated rosette ossicles in the tentacles. The tentacle ossicles of the new species comprise only oval, simple, open rosettes, 20–40 µm in length, while the other congeners possess rods/elongated rosette-shaped ossicles in the tentacles (very rarely also table ossicles). This new species has been collected from the shallow waters of western Japan living amongst boulder area in the intertidal-subtidal zone, at a depth of approximately 0–20 m.
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

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.