|
The don't. All their color is lost only during prolonged or sever bleaching events. Many bleaching events result in changes so minor its not noticeable to the human eye. Often, when corals "lighten up" or "color up" in aquariums, its a result of partial bleaching. Also, if you look at my article on bleaching at advanced aquarist, you will see a photo of a Euphyllia that is very bleached but still has its fluorescent proteins. Bleaching is a continuum.
Also, the method of bleaching can involve variously "strenuous" methods. The zoox can be released a few at a time into the coelenteron, they can be purged in pellets, or in streams. During very acute events, most of the cell contents can be purged, including the fluorescent proteins, and sometimes the entire endodermal cell is released.
Hope that explains it a bit.
__________________
Eric Borneman
|