紅潮來了?
- KingArthur
- 夸克星
- 文章: 2398
- 註冊時間: 週四 14 8月, 2003 17:50
- 來自: Lantau
紅潮由腰鞭毛蟲(dinoflagellate, 單細胞生物)引起。Eddy So 寫:紅潮不是應該是紅色的嗎?為何是藍色的?
腰鞭毛蟲體內的物質, 包括某種葉綠素, 會吸藍綠色光, 同時會產生紅色螢光(fluorescence), 所以在陽光下, 含大量腰鞭毛蟲的海水會是紅色的。
但沒有陽光, 沒有吸光和螢光。
腰鞭毛蟲還有另一種產生光的方式, 是當腰鞭毛蟲受壓力, 如在白頭浪上(海浪)或海水拍打岸邊, 牠會有生物發光(bioluminescence), 這是由腰鞭毛蟲體內的化學物質引起的, 在東亞地區, 腰鞭毛蟲的生物發光多是藍色光。這種光很暗, 只在黑夜中才會見到。
因此, 在有紅潮時, 黑夜的浪, 岸邊或輪船的水花等, 都會有藍色的"閃光"。
參考: http://photobiology.info/Hastings.html
- KingArthur
- 夸克星
- 文章: 2398
- 註冊時間: 週四 14 8月, 2003 17:50
- 來自: Lantau
這個引發思考紅潮的生物學問題, 就是這種生物發光有何生物優勢呢?
找了點資料, 這個很有趣(也淺白):
找了點資料, 這個很有趣(也淺白):
From: http://jrscience.wcp.muohio.edu/FieldCo ... rBioA.htmlBioluminescence in Dinoflagellates
Bioluminescence is used to evade predators and acts as a type of burglar alarm defense mechanism in dinoflagellates. Dinoflagelletes produce light when the deformation of the cell by minute forces triggers its luminescence. When the cell is disturbed by a predator, it will give a light flash lasting 0.1 to 0.5 seconds. The flash is meant to attract a secondary predator that will be more likely to attack the predator that is trying to consume the dinoflagellate. The light flash also makes the predator jump and worry about other predators attacking it, making the predator less likely to prey on the dinoflagellate.
In most dinoflagellates, bioluminescence is controlled by an internal biological rhythm. Dinoflagellates are on a circadian rhythm. Towards the end of daylight, luminous chemicals are packaged in vesicles called scintillons. The scintillons then migrate to the cytoplasm from the area around the nucleus. It is not currently known how the scintillons are moved to the cytoplasm. At night, light is triggered by mechanical stimulation. When action potential generates in the vacuole, the action potential propagates throughout the rest of the cell. This allows protons to pass from the vacuole to the cytoplasm (where they were kept). The cytoplasm becomes acidified, normally by hydrogen ions, and the process is activated in the scintillons.
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