Berghia Nudibranch

Berghia stephanieae

Origin	Tropical Western Atlantic (aquacultured for the trade)
Maximum Length	0.75–1 inch
Minimum Tank Size	10 gallons
Reef Compatibility	Yes — beneficial; completely reef safe

Behavior

The Berghia Nudibranch is one of the most useful invertebrates in the reef hobby — it is the premier natural solution for eradicating Aiptasia, the pest anemones that plague many reef tanks. Small, white-to-cream colored with feathery cerata along its back, the Berghia hunts exclusively at night, gliding across rock to seek out and devour Aiptasia of all sizes. They are almost always aquacultured (captive-bred), making them a sustainable choice. Because they are nocturnal and cryptic, they are rarely seen once added — but their effect on an Aiptasia infestation becomes obvious within weeks. Best added in groups of several for effective control.

Diet & Feeding

Obligate Aiptasia predator. Berghia eat only Aiptasia anemones and nothing else — no other food is accepted or needed. Once all Aiptasia in the tank is consumed they will starve, so plan to move them to another infested tank, sell them back, or accept the population will decline as the pest is eliminated. Add enough to match the size of the infestation (typically 1 per 10 gallons, more for heavy infestations).

Cautions

Will starve once all Aiptasia is gone — they eat nothing else. Add only after confirming an Aiptasia problem. Vulnerable to being eaten by wrasses, peppermint shrimp, crabs, and many fish — best in tanks without predators, or add extra to offset losses. Keep away from unguarded powerhead intakes; they are tiny and soft-bodied. Sensitive to copper and poor water quality. Nocturnal and cryptic — do not expect to see them often.

Dealing with pests? See our guide: How to Get Rid of Aiptasia