亜熱帯性ホンダワラ類キレバモクの再生産過程における海洋深層水の利用(Use of Deep Ocean Water to Control Reproductive Processes of a Subtropical Sargassum alternato-pinnatum)
- 標題
- 亜熱帯性ホンダワラ類キレバモクの再生産過程における海洋深層水の利用(Use of Deep Ocean Water to Control Reproductive Processes of a Subtropical Sargassum alternato-pinnatum)
- 作者
- 池部 慶太(Keita Ikebe)
- 文件屬性
- 日本研究
- 知識分類
- 水產養殖
- 出版年
- 2013
- 刊名
- 海洋深層水研究
- 卷
- 14
- 期
- 1
- 頁
- P19-26
- 點閱數
- 2431
摘要
本研究の目的はキレバモクの再生産に関する生態学的知見を得ることおよび深層水を利用して本 種の幼8玉の放出を促進させる幼8玉採集方法を確立することである． 生殖器床を形成したキレバモク の幼8玉の放出に及ぼす水温・干出条件などの効果を培養水槽を用いて調べた． その結果，深層水（水 深約320-340 m から取水）との熱交換により低水温化させた表層水（水深約im から取水）を使 用することで放出される幼腫数が増加し，幼腫放出の周期および枯死が遅れることが明らかとなった． また，放出される幼8玉数は干出により抑制されるが，回復能力があることが認められた． これらの ことから，水温・水深などの環境条件の変化はキレバモクの再生産に大きな影響を与えることが示 唆された． また，キレバモクはほぼ同時に周期的に（少なくとも3回）幼8玉を放出することが確認 された． 以上のことから，深層水の低温特性を利用して表層水の温度を低下させることで，キレバ モクからより多くの幼8玉を獲得できることが明らかとなった．
The aims of this study were to investi即te the ecology of reproductive processes of Sargassum alternato-pinnatum, and to develop a method to induce the release of embryos from this species using deep ocean water. The effects of water temperature and air exposure on the number of embryos released from mature thalli of S. alternato-pinna飢m were examined. The main findings were as follows: more embryos were released into surface ocean water (from a depth of approx. 1 m) when the temperature was decreased by heat exchange with deep ocean water (from a depth of approx. 320-340 m). When the release of embryos was delayed, there was also a delay in withering of the algal thalli. Fewer embryos were released from the thalli after they were exposed to air, but the thalli were able to recover their embryo-releasing capacity. These results suggested that environmental changes such as shifts in water temperature, depth, etc. will greatly influence algal reproductive processes. There were at least three separate embryo-release events in S. alternato-pinnatum. In conclusion, it is possible to obtain many embryos from this alga by lowering the temperature of surface ocean water by heat exchange with colder deep ocean water.
The aims of this study were to investi即te the ecology of reproductive processes of Sargassum alternato-pinnatum, and to develop a method to induce the release of embryos from this species using deep ocean water. The effects of water temperature and air exposure on the number of embryos released from mature thalli of S. alternato-pinna飢m were examined. The main findings were as follows: more embryos were released into surface ocean water (from a depth of approx. 1 m) when the temperature was decreased by heat exchange with deep ocean water (from a depth of approx. 320-340 m). When the release of embryos was delayed, there was also a delay in withering of the algal thalli. Fewer embryos were released from the thalli after they were exposed to air, but the thalli were able to recover their embryo-releasing capacity. These results suggested that environmental changes such as shifts in water temperature, depth, etc. will greatly influence algal reproductive processes. There were at least three separate embryo-release events in S. alternato-pinnatum. In conclusion, it is possible to obtain many embryos from this alga by lowering the temperature of surface ocean water by heat exchange with colder deep ocean water.