well in the book Aquarium Corals: Selection, Husbandry, and Natural History by Eric Bornemanon-page 309 under the special inforamation (under the euphyllia sp.) it says as follows:
"It has been reported on several occasions that sweeper tentacle tips of E. ancora may sometimes stick to substrate and break off, where they can then form new colonies. If this is true, it would be a totally novel and hither to undocumented form of asexual reproduction or a generalized defense mechanism. Tentacle tips with swollen acrospheres are more likely to become detached, and the drifting tips, completely sealed like neutrally buoyant water balloons, stick onto virtually any surface they encounter."
Kelly