As many marine aquarists know, Aiptasia or glass anemones, as some people like to refer to them, are an aquarium pest that we all dread seeing in our beloved aquariums. This article will explore some of the ins and outs of the different methods of
biologically/naturally removing aiptasia from the reef aquarium.
Berghia Nudibranch
Berghia eat Aiptasia. Aiptasia is all they eat. This is a plus but keep in mind they will starve off once the aiptasia is gone. The average life expectancy is 6-8 months but it's common for them to reproduce in captivity. Because berghia are nocturnal, you most most likely will not see them once they are introduced into your tank unless you like to stay up late at night and shine a flashlight into your tank to search for them. With berghia, patience is key. Berghia are not an overnight cure to eliminating aiptasia, and depending on the aquarium size and population of berghia to aiptasia it can take weeks or months for a herd of berghia to wipe out aiptasia in a reef aquarium. Important things to consider when buying berghia are acclimation, introducing them with the lights out, and turning off all the pumps for an hour or so.
Peppermint Shrimp (Lysmata seticaudata)
Aiptasia Eating Peppermint Shrimp are best known for their ability to manage nuisance Aiptasia but they will also eat fish food and other organics in the home aquarium. As a result of their less selective diet they don't die off if the aiptasia disappear from sight. The great thing about Peppermint Shrimp is that they eat aiptasia rapidly and they can easily clean up a tank in a few days to a couple of weeks. So the question presents itself, "Why doesn't everyone use these little guys instead of berghia?" For one, the problem lies with identification. Too often people pick up peppermint shrimp at the local fish store and they turn out to be the wrong ones (Rhynchocinetes durbanensis - Pacific Ocean). Unfortunately stores don't always get what they think they are getting and all too often the wrong shrimp are sold as a cure for aiptasia and then the aquarists feels jilted when the cure doesn't turn out to be a cure at all. Rhynchocinetes durbanensis don't recognize aiptasia as a potential food source since it's not indigenous to the habitat from where they are collected. So how can you tell the difference? It's pretty easy if you take you time and look closely at the "nose" of the shrimp. Rhynchocinetes durbanensis have a pointed nose and interspaced white stripes over it's body and Lysmata seticaudata does not. Another reason to consider berghia over Lysmata shrimp is that shrimp often can't physically get to the entire aiptasia polyp. Even if a little bit of the aiptasia tissue is left behind (a cell or 2) this tissue can regrow into to a new anemone after the peppermint shrimp have died off. Typically peppermint shrimp can't physically get to each and every single speck of aiptasia tissue on every aiptasia within an aquarium thus it's not uncommon for aiptasia to regrow once the shrimp are gone. Still, the right peppermint shrimp are a great way to manage aiptasia in a reef aquarium but don't be surprised if they return when the shrimp have died out.
Some Common fish that will eat Aiptasia
Kleini's Butterfly Fish (Chaetodon kleini)
Long Nosed Butterfly Fish (Forcipiger flavissimus)
Copper banded Butterfly Fish (Chelmon rostratus)
File Fish (Acreichthys tomentosus)
Of the fish listed above, which one would you choose? Well, for me, it would be the Klein's Butterfly fish but only if your aquarium is at least 120 gallons and you don't mind if the Klein can't eat every living cell of Aiptasia growing in your system. All of the Butterfly fish listed above are best suited for aquariums 120 gallons and larger so if your tank is smaller than 120 gallons then we don't recommend picking up one of these fish. Additionally, as touched on above, fish have a hard time getting to all of the aiptasia in an aquarium. If the fish dies or you decide to pull him/her out of the aquarium then chances are high that the aiptasia will come back. Fish behavior can very from fish to fish, even in the same species, so choosing a butterfly fish can sometimes be tricky. Like people, fish can behave very different from one another. Not to get side tracked but I once had a yellow tang about 15 years ago that would let me pet him like a dog while other yellow tangs would dart off every time I approached the tank. OK, back on track.. some butterfly fish may pick at and harm certain corals but I have kept at least 3 different Klein's in my personal reef tanks over the years and they have all been peaceful towards the corals. Aditionally they are fairly hardy, will easily accept various foods and they are realitively inexpensive for butterfly fish. Therefore, the Klein's is my top pick for butterfly fish that will eat aiptasia.
Ok so what about the tomentosus file fish? There has been a bit of a buzz lately about this species of file fish eating aiptasia so I decided to try one out about 6 months ago to see if the hype was real or perceived. Well, as it turns out they can tear through some aiptasia like a combine through corn field but that's not all they can munch on. These little fish are pretty sturdy but like the butterfly fish and peppermint shrimp, they can't get to the whole animal so expect aiptasia regrowth if the fish is removed or falls to Davy Jones's locker. Also, my short lived experience with these fish has shown that they also love the taste of zoas, palys and scolys once they run out of accessible aiptasia to eat. They are probably also fond of other fleshy LPS corals but I haven't personally tested this theory yet nor do I want to. We currently have one of the little monsters, and he's cute but don't plan on keeping the above corals in a tank with one of these little guys. As a result of adding this fish we had to remove all of the corals from the "file fish tank" with the exception of our chalice corals, cyphastrea and mushroom corals.
To sum things up, Berghia are host specific aiptasia predators and they will eat the entire aiptasia but they won't set any speed records in doing so. If patience is your virtue then berghias are the way to go. The forementioned fish and Lysmata seticaudata Peppermint Shrimp will quickly remove visible signs of aiptasia in areas where they can physically get to but expect aiptasia to return in the event that the shrimp or fish are removed from service in one way or another.
