著者

Miles I Peterson Kei Chloe Tan Allen Collins Satoshi Kitano Yasushi Kusuoka Takahito G Suzuki Masao Migita Iffah Iesa Stacy Pirro Dhugal Lindsay Cheryl Lewis Ames

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.231-248, 2022-05-30 (Released:2022-05-31)

参考文献数

39

被引用文献数

2

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Freshwater jellyfish comprising the genus Craspedacusta are thought to have originated in the Yangtze River, China and have since spread to all continents except Antarctica. In this study, jellyfish were collected from Haruta-ike, an artificial pond in Chikuma City, Nagano (Japan). Medusae were identified as Craspedacusta sowerbii using morphological and molecular techniques. Despite the existence of Haruta-ike since prior to the Edo era (ca. 1603), this work represents the first published record of freshwater jellyfish in this pond. Herein, we report on the novel swimming behavior documented in this population, which includes both male and female C. sowerbii medusae. Additionally, we discuss the life cycle of polyps reared in culture from Machikane-ike, a pond in Osaka for which we have published the first complete mitochondrial genome of C. sowerbii from Japan. Finally, we report on the morphology and life cycle of the rare Japanese freshwater jellyfish Astrohydra japonica in Lake Biwa (Shiga), documented only a few times in the 40 years since its original discovery in Japan. The results of our robust phylogenetic analysis using the 16S rRNA gene and COI markers of C. sowerbii and A. japonica in this study and for C. sowerbii material from Singapore, together with all publicly available sequences for these markers for the two species worldwide, revealed two major C. sowerbii clades suggesting the Nagano and Osaka populations originated from two distinct introduction events. This collaborative research was made possible through international collaborations among multiple research facilities, museums and one wildlife reserve.

著者

Susumu Ohtsuka Kazuhiko Koike Dhugal Lindsay Jun Nishikawa Hiroshi Miyake Masato Kawahara Nova Mujiono Juro Hiromi Hironori Komatsu

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.4, no.1, pp.1-13, 2009-02-25 (Released:2009-04-20)

参考文献数

91

被引用文献数

45 53

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Since marine medusae and ctenophores harbor a wide variety of symbionts, from protists to fish, they constitute a unique community in pelagic ecosystems. Their symbiotic relationships broadly range from simple, facultative phoresy through parasitisim to complex mutualism, although it is sometimes difficult to define these associations strictly. Phoresy and/or commensalism are found in symbionts such as pycnogonids, decapod larvae and fish juveniles. Parasitism and/or parasitoidism are common in the following symbionts: dinoflagellates, ciliates, anthozoan larvae, pedunculate barnacles, anuropid isopods, and hyperiid amphipods. Mutualism is established between ctenophores and gymnamoebae, and between rhizostome medusae and endosymbiotic dinoflagellates. More information on symbiotic apostome ciliates, anthozoan larvae and hyperiid amphipods is definitely needed for further studies in consideration of their high prevalence and serious damage they can inflict on their hosts. The present paper briefly reviews previously published data on symbionts on these gelatinous predators and introduces new information in the form of our unpublished data.

著者

Ichiro Takeuchi Momoko Shiraishi Dhugal Lindsay

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.18, no.4, pp.190-197, 2023-11-27 (Released:2023-11-30)

参考文献数

43

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During an ROV Hyper-Dolphin dive to bathyal depths in the Kamaishi Marine Canyon, off Tohoku District, the north Pacific, the association of a large specimen of Caprella (Crustacea: Malacostraca: Amphipoda) was observed, surrounded by juveniles, clinging to the dorsal tube feet of the deep-sea holothurian Scotoplanes globosa (Théel, 1879) at 1142 m depth. Scotoplanes globosa “walks” on the seafloor using long tube-like limbs extending from its body. The present observation indicated that “walking” deep-sea holothurians are an underrated substrate for Caprella spp. in the bathyal depths. Approximately 25 juveniles were collected with the mature female specimen from the same holothurian. These individuals were identified as Caprella fimbrillata Vassilenko, 1993 which has previously been reported from the eastern seaboard of Etorofu/Iturup Island, Chishima/Kuril Islands, in 605 to 1200 m water depth; these sites are located approximately 600 km northeast from the present site off Tohoku in the northwest Pacific. The mature female was closely surrounded by juveniles on the same deep-sea holothurian, suggesting maternal care by the mother caprellid in the bathyal depth environment.