- 著者
- Tomohiro Nishimura Wittaya Tawong Hiroshi Sakanari Takuji Ikegami Keita Uehara Daiki Inokuchi Masatoshi Nakamura Takuya Yoshioka Shota Abe Haruo Yamaguchi Masao Adachi
- 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.13, no.2, pp.46-58, 2018-05-30 (Released:2018-05-24)
- 参考文献数
- 68
- 被引用文献数
- 13
Ciguatera fish poisoning (CFP) is caused by toxins originating from an epiphytic/benthic dinoflagellate of the genus Gambierdiscus. In Japan, CFP cases have been increasingly reported not only in subtropical areas but also in temperate areas. It is therefore important to study Gambierdiscus cell occurrences, cell densities, and population dynamics to address CFP outbreaks in Japan. This study assessed the densities in Japanese shallow waters (0.1–3 m depths) and revealed that the densities were lower than those in tropical and subtropical areas worldwide. In the shallow waters of Tosa Bay, a Japanese temperate area, population dynamics of Gambierdiscus cells were assessed monthly between 2007 and 2013. Gambierdiscus did not show substrate preferences for macroalgal species. The cell densities in the area ranged from 0 to 232.2 cells g−1 wet weight algae. The average cell densities in spring, summer, autumn, and winter were 0.1±0.4, 0.9±2.6, 4.0±20.6, and 0.4±1.4 cells g−1 wet weight algae, respectively. The cell densities in summer and autumn were not significantly different (p>0.05), whereas those in summer and autumn were significantly higher than those in spring and winter (p<0.01). A significant positive correlation between cell densities and sea surface temperatures (SSTs) was observed (rs=0.21, p<0.001), while a significant negative correlation between cell densities and salinity was recognized (rs=−0.18, p<0.001). These results suggest that cell densities of Gambierdiscus in Japanese temperate shallow waters increase in summer and autumn when the SST is high and salinity is moderately low.
- 著者
- 松田 篤志 西島 敏隆 深見 公雄 足立 真佐雄 Atsushi Matsuda Toshitaka Nishijima Kimio Fukami Masao Adachi 高知大学農学部栽培漁業学科:(現)熊本市役所 高知大学農学部栽培漁業学科 高知大学農学部栽培漁業学科 高知大学農学部栽培漁業学科 Department of Aquaculture Faculty of Agriculture Kochi University:(Present address)Kumamoto City Office Department of Aquaculture Faculty of Agriculture Kochi University Department of Aquaculture Faculty of Agriculture Kochi University Department of Aquaculture Faculty of Agriculture Kochi University
- 出版者
- The Japanese Society of Fisheries Science
- 雑誌
- 日本水産学会誌 = Bulletin of the Japanese Society of Scientific Fisheries (ISSN:00215392)
- 巻号頁・発行日
- vol.67, no.4, pp.658-663, 2001-07-15
- 参考文献数
- 32
- 被引用文献数
- 2
A. catenellaの増殖に及ぼすB群ビタミンの影響をバッチ培養系において調べた。本藻はB群ビタミンのうちビタミンB_<12>を増殖に必須に要求し, 増殖のB_<12>半飽和定数(Kμ)は0.22ng/L, 最大比増殖速度(μ'm)は0.55 day^<-1>, 最小細胞内B_<12>含量(q_0)は0.65fg/cell, 単位細胞体積当たりのB_<12>含量は27分子/μm^3と算出された。本藻は, 他の栄養物質が充足されている場合, 富栄養化の進んだ沿岸・内湾域のようにB_<12>供給量が多い海域では最大に近い比増殖速度で増殖できると考えられた。また, Kμ, μ'mを他の赤潮プランクトンと比較した結果, 本藻は低B_<12>濃度下で一部の赤潮プランクトンよりも優位に増殖できると推察された。Physiological growth characteristics of Alexandrium catenella (Whedon et Kofoid) Balech, toxic dinoflagellate, were examined in axenic, batch cultures with specific reference to B group vitamin requirements. A. catenella required essentially vitamin B_<12> among the B group vitamins for their growth. It was found that growth rates and final cell yields were dependent on the vitamin B_<12> concentrations in the media. Under the conditions of our batch culture experiments, the half-saturation constant for growth of vitamin B_<12>(Kμ) and maximum growth rate (μ'm) were 0.22ng/L and 0.55 day^<-1>, respectively. The minimum cell quota of vitamin B_<12> was estimated at 0.65 fg/cell or 27 molecules/(μm)^3 of the cell volume. In this experiment, A. catenella could grow at almost a maximum growth rate at high vitamin B_<12> levels of eutrophied coastal waters. The comparison of Kμ and μ'm between A. catenella and other red-tide species suggests that this organism can win competition with some red-tide species under low B_<12> concentrations.