Berghia Nudibranch (Berghia stephanieae)

The Berghia Nudibranch is the reef hobby's go-to natural weapon against Aiptasia, the stinging pest anemones that spread across rock and glass and torment nearby corals. This small sea slug — barely an inch long — eats nothing but Aiptasia, hunting them down after dark and clearing them out with no chemicals, injections, or scraping. It's completely reef safe, harmless to corals, other invertebrates, and fish, and works best added in a small group so they can find each other, breed, and stay ahead of the infestation. The one catch is their strict diet: once the Aiptasia are gone they'll need a fresh supply or a move to another infested tank, since they won't touch anything else. For a stubborn Aiptasia problem, a few Berghia are about the most elegant fix there is.

Care level: Easy · Reef safe: Yes · Diet: Aiptasia anemones only