Another reefkeeping area with many myths, misconceptions and gotchas. Berghia are reported to be a natural predator of aiptasia.
Supposedly will not harm anything in tank. Only preys on aiptasia.
(2) physical threats
No real defined threats. However, always watch to see if fish or other reef life seem to be hunting the reef. They could possibly be hunting your Berghia.
(3) required number
Some sources recommend 8 Berghia per 100 gallons of water for a moderate to heavy aiptasia problem.
Berghia ONLY feed on aiptasia. Without aiptasia, they will starve.
Berghia are hermaphroditic. They have the potential to repopulate and expand there numbers quickly when the conditions are right.