著者

Sho Toshino Jun Nishikawa Khwanruan Srinui Supattra Taleb Hiroshi Miyake

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.14, no.3, pp.143-149, 2019-08-26 (Released:2019-08-17)

参考文献数

29

被引用文献数

2

---

The stings of box jellyfishes can be fatal, so knowing the fauna of a certain area is important to save lives. Five described and two still-undescribed species of Cubozoa have been reported from Thailand: Chironex indrasaksajiae, Chironex sp., Chiropsella sp., Chiropsoides buitendijki, Copula sivickisi, Morbakka fenneri, and Tripedalia cystophora. We made detailed observations of the morphology of two of the species newly recorded in Thailand: Alatina morandinii and Tripedalia binata. The molecular phylogeny of these species is also discussed. Additional investigations are needed to understand the diversity of Cubozoa in Thailand.

著者

Yuki Hamaguchi Akane Iida Jun Nishikawa Euichi Hirose

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.221-227, 2021-08-06 (Released:2021-07-31)

参考文献数

20

被引用文献数

2

---

Mastigias papua, known as the golden (or spotted) jellyfish, is an epipelagic jellyfish widely distributed in the warm waters of the West Pacific. This jellyfish has a brownish body, owing to zooxanthellae, and white spots. We measured the maximum force to pierce the umbrella, which averaged 94–144 mm in diameter, to evaluate the hardness of M. papua, and returned a range of 0.14–0.45 N. Correlation analyses indicate that when the M. papua medusa grows (i.e., becomes heavier), the umbrella becomes larger in diameter, as well as thicker and harder within the size range we examined. However, a significant relationship between the hardness of the umbrellar apex and the thickness of the umbrella was not obtained. White spots are comprised of loose aggregates of mesogleal cells containing reflective granules. Since the white spots and the transparent parts were not significantly different in hardness, the spots were unlikely to strengthen the umbrella. The primary function of the spots may be the shading of solar radiation. Most of the zooxanthellae are located in mesogleal cells, and often beneath the exumbrellar epidermis. Therefore, light shading by white spots may be unnecessary for the zooxanthellae in mesogleal cells.

著者

Akiyuki Kenmochi Hiroyuki Matsuura Takashi Yoshikawa Rumi Sohrin Yumiko Obayashi Jun Nishikawa

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.1, pp.57-65, 2022-02-22 (Released:2022-02-23)

参考文献数

53

被引用文献数

1

---

Seasonal occurrences of marine cladocerans in offshore Suruga Bay, Japan, were studied from 2014 to 2019. Zooplankton samples were collected monthly from a station (depth: ca. 1000 m) located in the offshore area of the bay. Cladocerans appeared each year from February to December, and disappeared in January. Their abundance increased drastically from April to September and comprised a substantial portion of the offshore mesozooplankton community during this period. Maximum cladoceran abundance occurred from June to August, ranging from 65.9–1341.9 individuals m−3. These patterns in cladoceran abundances were basically repeated each year throughout the study period. This result suggests that mass occurrences of cladocerans in offshore regions of the bay during the spring-summer are regular events rather than sporadic. Seven species, which have previously been reported from Japanese waters, were identified, and successional changes in the dominant species were observed. The most abundant species, Penilia avirostris, carried parthenogenetic embryos in brood pouches, suggesting that they were not simply transported from coastal areas, but that they also reproduce in the offshore waters. Regular mass occurrences of marine cladocerans in offshore Suruga Bay could have an important impact on the offshore ecosystem of the bay, and factors enabling these population cycles need to be determined.

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

---

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

Akane Iida Kenji Nohara Fatimah Md. Yusoff Khwanruan Srinui Tran Manh Ha Susumu Ohtsuka Ephrime B. Metillo Honorio B. Pagliawan Jun Nishikawa

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.4, pp.308-317, 2021-11-17 (Released:2021-11-18)

参考文献数

63

---

The rhizostome jellyfishes, Rhopilema hispidum and Lobonemoides robustus, are two of the most abundant and commercially important species in Southeast Asia. However, information on genetic diversity and continuities among local populations remains totally unknown. We explored the genetic structure and population continuities of R. hispidum and L. robustus using genetic markers (COI & ITS1 regions) at 11 locations in four countries in Southeast Asia where fisheries were conducted. Rhopilema populations showed genetic distances (ΦST) among locations correlated positively with geographic distances, suggesting that they are in the isolation-by-distance (IBD). In Lobonemoides, molecular analysis revealed three distinct clades corresponding to sampling locations. Genetic distances among locations in L. robustus suggested that all populations maintain significant isolation. Our study reveals that these two blooming species have different phylogeographic patterns and differ in genetic diversity and continuities. Eustatic sea level changes during the Pleistocene and present ocean current systems, as well as differences in biological characteristics of these two species may explain these phylogeographic differences. Our results also suggest that jellyfish fisheries need to be carefully managed to avoid extinction of local populations and maintain the genetic diversity of these species, especially for L. robustus, which exhibits considerable genetic diversity in each location.

著者

竹田 健太郎 西川 純 Kentaro Takeda Jun Nishikawa

出版者

上越教育大学

雑誌

上越教育大学研究紀要 = Bulletin of Joetsu University of Education (ISSN:09153162)

巻号頁・発行日

vol.39, no.1, pp.37-44, 2019-08-30

著者

谷村 篤 岡 信和 川口 創 西川 淳 高橋 邦夫 真壁 竜介 Hosie Graham 小達 恒夫 Atsushi Tanimura Nobukazu Oka So Kawaguchi Jun Nishikawa Kunio T. Takahashi Ryusuke Makabe Graham Hosie Tsuneo Odate

雑誌

南極資料 = Antarctic Record (ISSN:00857289)

巻号頁・発行日

vol.52, no.1, pp.1-8, 2008-03

---

2002年及び2003年の南極海の夏季,東部インド洋区のウイルクスランド沖の東経140度線上において,白鳳丸及びタンガロアによる3回の調査航海によって行われたRMT-8(目合: 4.5mm, 開口面積: 8m3)ネット採集によって得られた標本に基づいて,大型動物プランクトン群集構造を調べた.クラスター解析の結果,大型動物プランクトン群集は,南極周極流の南縁(SB-ACC: Southern Boundary of the Antarctic Circumpolar Current)で大きく二つの群集に分けられた.すなわち,SB-ACCの北方では大型動物プランクトン群集は,Salpa thompsoni, Euphausia frigida及びThemisto gaudichaudiiなどのoceanic communityが卓越していた.一方,SB-ACCの南方ではEuphausia superba及びEuphausia crystallorophiasなど大陸寄りに主分布域をもつ動物プランクトンが卓越していた.SB-ACCは,南極海の上記の主要な大型動物プランクトン種の出現の差によって特徴付けられることが示唆された.

著者

Jun NISHIKAWA Richard FITZPATRICK James D. REIMER Robin J. BEAMAN Hiroyuki YAMAMOTO Dhugal J. LINDSAY

出版者

日本サンゴ礁学会

雑誌

Galaxea, Journal of Coral Reef Studies (ISSN:18830838)

巻号頁・発行日

vol.13, no.1, pp.25-26, 2011 (Released:2012-03-24)

参考文献数

3

被引用文献数

1 6 1