著者

Natsumi Hookabe Yuki Oya Shinji Tsuchida Yoshihiro Fujiwara Rei Ueshima

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.199-204, 2023-08-31 (Released:2023-08-31)

参考文献数

23

---

Monostiliferous nemerteans are mostly benthic and free-living, but a few are recognized as commensal and parasitic species. We describe Tetrastemma carneum sp. nov. based on five specimens found from demosponges collected by the use of remotely operated vehicle at a depth of 398 m, off Ofunato, Japan. The new species resembles T. appendiculatum Chernyshev, 1998 described based on specimens discovered from demosponge Esperiopsis digitata (Miklucho-Maclay, 1870) (now accepted as Amphilectus digitatus) trawled at depths of 40–60 m in Peter the Great Bay, in having a pale-colored body with four conspicuously large eyes (approximately 50 µm in the maximum width). However, it is differentiated from T. appendiculatum in possessing a mid-dorsal line on the dorsal surface of the head as well as the number of proboscis nerves. In our molecular phylogenetic tree based on partial sequences of 16S rRNA, cytochrome c oxidase subunit I, 18S rRNA, 28S rRNA, and histone H3 genes, Tetrastemma carneum sp. nov. was nested in the clade of Tetrastemma Ehrenberg, 1828 as a sister taxon to Tetrastemma sp. IP Iturup reported from Peter the Great Bay.

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

---

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

Naoto Jimi Naohiro Hasegawa Masanori Taru Yuki Oya Hisanori Kohtsuka Shinji Tsuchida Yoshihiro Fujiwara Sau Pinn Woo

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.101-111, 2022-04-15 (Released:2022-04-15)

参考文献数

15

---

Members of the family Flabelligeridae are distributed worldwide, inhabiting the underside of rocks or within mixed sand sediments. Some genera of the family have gelatinous tunics with hooked chaetae. The genus Flabelligera Sars, 1829 is one of the members of the gelatinous free-living groups of Flabelligeridae. A fan-shaped cephalic cage, thick gelatinous tunic, and hooked neurohooks distinguish members of this genus. In Japan, Flabelligera affinis Sars, 1829 [Japanese name: Kanten-habouki] has been known as the sole Japanese species of Flabelligera inhabiting several locations. We reviewed Japanese species of Flabelligera from several sites from Hokkaido to Honshu and concluded that the Japanese “F. affinis” contained at least five different species under the specific name. In this study, we described them as five new species. All new species were collected from the underside of rocks in shallow to deep-sea depths. We have also provided mitochondrial cytochrome c oxidase subunit I sequences for DNA barcodes of the new species.

著者

Natsumi Hookabe Shinji Tsuchida Yoshihiro Fujiwara 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.183-188, 2020-08-08 (Released:2020-08-08)

参考文献数

24

被引用文献数

8

---

The monostiliferous hoplonemertean Proamphiporus kaimeiae sp. nov. is described based on a single specimen collected from the bottom of the Northwest Pacific, 262 m deep, off Tohoku in Japan, by use of a remotely operated vehicle during a cruise organized by Tohoku Ecosystem-Associated Marine Sciences (TEAMS) research project in 2019. The position of the cerebral organs in the new species, being posterior to the proboscis insertion, is unusual for Eumonostilifera, which is one of the diagnostic traits of the so-far monospecific Proamphiporus Chernyshev and Polyakova, 2019, and Amphiporus rectangulus Strand, Herrera-Bachiller, Nygren, and Kånneby, 2014. The latter is herein transferred to Proamphiporus to yield a new combination, Proamphiporus rectangulus comb. nov., based on the reported internal morphology. Molecular phylogenetic analyses based on 16S rRNA, cytochrome c oxidase subunit I, 18S rRNA, 28S rRNA, and histone H3 genes placed P. kaimeiae in a clade comprised of Proamphiporus crandalli Chernyshev and Polyakova, 2019 and Proamphiporus rectangulus.

著者

Akinori Yabuki Masaru Kawato Yuriko Nagano Shinji Tsuchida Takao Yoshida Yoshihiro Fujiwara

出版者

Japan Society of Protistology

雑誌

Journal of Protistology (ISSN:2433412X)

巻号頁・発行日

vol.52, pp.1-5, 2020-07-27 (Released:2020-07-27)

参考文献数

19

---

Diplonemea is one of the most abundant and species-rich protist groups in marine environments. However, many lineages are still undescribed. Particularly, little is understood about members of the ‘deep-sea and pelagic diplonemids (DSPD)’ clade. The environmental DNA (eDNA) studies conducted with universal eukaryotic primers have shown that DSPDs were also abundantly distributed in natural environments, but their cultures have not yet been established. For future studies such as mitochondrial genome sequencing, culture establishment is needed. For establishing cultures, it is important to select samples containing a high quantity of diplonemids. In this study, we designed new diplonemid primers for eDNA analysis using a next-generation sequencer, testing its efficiency using eDNA that was extracted from two deep-sea water samples. Out of a total of 58,154 assembled reads, 57,633 reads (i.e. 99.1%) were affiliated with diplonemids by BLAST and reconstructed into 160 representative sequences. Phylogenetic analyses showed that many of the representative sequences (137 sequences, 85.6%) were branched within the DSPD clade and family Hemistasiidae. These findings indicate that the new primers are useful in monitoring diplonemid diversity and acquiring information for the establishment of DSPD cultures.