Borneman covers a couple of different reproductive modes of corals, including various forms of asexual reproduction such as budding and fission. In each one, tissue separates from the parent colony and then begins to calcify and form a new skeleton. These forms of reproduction are thought to be responses to stressful conditions. Coral tissue may bud and separate, the coral may intentionally decalify part of its skeleton to release some of its tissue, or eject a living polyp from its skeleton. Regarding polyp bailout, note, p. 81, "There are also reports of Catalaphyllia, Trachyphyllia, and a few other genera of large-polyped stony corals releasing living tissue from their skeletons in captivity to drift and then begin the calcification of a new skeleton. Again, these incidents usually follow a period of stress. It is not known if this observed aquarium behavior is analogous to the true polyp bail-outs reported in the scientific literature."
In the section on Coral Health, Borneman again talks about decalcification and polyp bail out. In decalcification in captivity, the author states that the most common cause is the lack (in the water) of "bioavailable calcium, carbon sources, or other elements required for skeletogenesis." No mention is made of the liklihood of loose polyps to survive; only that correcting the environmental problems will usually stop the decalcification process. Polyp bailout occurs usually in response to disease or stress, and correction of the cause is necessary to halt the progression of the bailout. Settlement of the loose polyps is more likely to occur in a stable aquarium without a lot of circulation.
***My question: is there a way to tell whether the coral in question has undergone decalcification vs. polyp bailout?
