著者

Aoi Tsuyuki Hisanori Kohtsuka Natsumi Hookabe Hiroshi Kajihara

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.17, no.2, pp.147-155, 2022-05-30 (Released:2022-05-31)

参考文献数

26

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The cotylean polyclad flatworm Bulaceros porcellanus Newman & Cannon, 1996 has so far only been recorded in a few tropical locations in the Indo-Pacific Ocean, including the Lakshadweep Islands (India), the Great Barrier Reef (Australia), and the Marshall Islands (Republic of the Marshall Islands). In this study, we report B. porcellanus for the first time from Japanese waters based on specimens collected in Misaki (Kanagawa) along the Pacific coast of Honshu. This new record expands the species’ known geographic distribution northward to include the warm temperate region of Japan. Our molecular phylogenetic analysis revealed that B. porcellanus formed a clade with Pseudoceros harrisi Bolaños, Quiroga & Litvaitis, 2007, and was separated from the monophyletic group composed of 19 other species of Pseudoceros Lang, 1884, including its type species Proceros velutinus Blanchard, 1847 (now Pseudoceros velutinus). Based on the morphological and phylogenetic closeness between P. harrisi and B. porcellanus (type species of Bulaceros Newman & Cannon, 1996), we transfer P. harrisi into Bulaceros with a revision of the diagnosis of Bulaceros.

著者

Yuki Oya Aoi Tsuyuki Hiroshi Kajihara

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.189-196, 2020-09-18 (Released:2020-09-18)

参考文献数

26

被引用文献数

2

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We describe a new species of ilyplanid polyclad, Zygantroides serpulidicola sp. nov., from Amakusa, Kumamoto, Japan. This is the third member of Zygantroides Faubel, 1983 and the first record of the genus from the Pacific Ocean. Zygantroides serpulidicola sp. nov. is characterized by i) the mouth opening near the common gonopore, ii) the sperm ducts separately entering a pear-shaped seminal vesicle, iii) an elongated Lang’s-vesicle duct, and iv) the horseshoe-shaped Lang’s vesicle located posterior to the common gonopore. We provide a partial sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene (712 bp) as a DNA barcode for the species. Our phylogenetic analyses based on concatenated sequences of the 16S, 18S, and 28S ribosomal DNA and COI indicate that Z. serpulidicola sp. nov. is nested in a clade comprised of Discocelidae and Ilyplanidae; the latter does not appear to be monophyletic.

著者

Aoi Tsuyuki Yuki Oya 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.137-143, 2019-07-25 (Released:2019-07-25)

参考文献数

21

被引用文献数

2

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We describe a new species of polyclad flatworm, Prosthiostomum torquatum sp. nov., from the rocky intertidal zone in Shirahama, on the Pacific coast of middle Honshu, Japan. Prosthiostomum torquatum is characterised by a unique dorsal colouration, which is comprised of i) numerous orange maculae and blue dots dispersed all over the dorsal surface, ii) a transverse dark-brown line in the anterior part of the body running slightly anterior to another transverse white line, both of which are slightly bent backwards at mid-point, and iii) an incomplete, mesh-like, median band made by dark-brown pigments, fading away posteriorly. By this dorsal colour pattern, the new species can be distinguished from similar congeners such as P. trilineatum Yeri and Kaburaki, 1920 and P. komaii Kato, 1944. We performed a molecular phylogenetic analysis based on 462-bp partial mitochondrial cytochrome c oxidase subunit I (COI) sequences of four species of Prosthiostomidae currently available in public databases in addition to that of P. torquatum. In the resulting tree, P. torquatum was sister to Lurymare clavocapitata Marquina, Aguado, and Noreña, 2015 originally described from Lizard Island, Australia. While these two share a similar dorsal colouration, P. torquatum can be distinguished from L. clavocapitata by i) the absence of a common muscle bulb/sheath enclosing the whole male copulatory apparatus, ii) the median mesh-like band comprised of dark-brown pigments, and iii) COI uncorrected p-distance being 0.094. As a result, our phylogenetic tree indicates the possibility that Prosthiostomum and Lurymare as currently diagnosed may not be monophyletic, and that the common muscle bulb enclosing the whole male copulatory apparatus may not be appropriate as a diagnostic character for Lurymare.