How To Kill Aiptasia

By: Chewy EditorialPublished:

How To Kill Aiptasia

Aiptasia anemones (Aiptasia spp.) are not to be taken lightly. Aiptasia have managed to spread from the ocean to many marine aquariums. This is because it only takes a single cell for this anemone to turn into a polyp and then quickly turn into five, 20 and so on. If not dealt with immediately, they can and will completely take over your reef tank in very little time. Once aiptasia gain a foothold, it can be almost impossible to remove them; this is a big reason why aiptasia is considered one of the most prolific and nettlesome fish aquarium pests facing marine hobbyists. If you are an experienced hobbyist, chances are you have already dealt with this pest; if you are a newcomer, you will sooner or later. Many novice marine aquarists, already awestruck by all the new life blooming in their created ecosystems, often overlooked or misidentified aiptasia until it’s too late.

There are many different species of aiptasia, the most common being Aiptasia pallida and A. pulchella. To identify them look for a light brown transparent polyp with long brown tentacles. The tentacles stretch out from the oral plate connected to a long body column down to the pedal. Given the right environment, I’ve seen aiptasia reach up to 4 inches long and 21/2 inches wide. They are equipped with one of the most powerful stings (delivered by structures called nematocysts), which they use to kill other corals (they can kill clams, too) and take over real estate.

Aiptasia are Stealthy Stowaways

Aiptasia is a known hitchhiker. Aiptasia enter the hobby by trading between hobbyists or even purchasing corals from your local pet store. Aiptasia can gain entry into our aquariums via rocks, frags, plumbing, water or any other matter from an infected tank. Generally, aiptasia doesn’t ride in on healthy corals, but if a specimen has any dead tissue, watch out! These “dead zones” have the potential to pick up and carry aiptasia into our aquariums. Preventing them from getting into your tank in the first place may seem almost impossible. They can sneak past even the closest eye or remain dormant on corals or live rock for months in quarantine, only to proliferate once they become established in a display.

There is even a decent chance that some of the tanks in the local fish store (LFS) you buy from could be infected with aiptasia. They should already be using biological controls, but if they aren’t, they are putting the you and their other customers at risk. To find out if aiptasia are present at your LFS, ask to check their sumps or overflow boxes; these areas receive the least amount of maintenance and so have a higher chance of aiptasia lurking within. If you find out after the fact that your LFS has aiptasia, it’s not the end of the world! Just be ready for their debut in your reef tank and for the battle to come.

Aiptasia Pedigree
Phylum: Cnidaria
Class: Anthozoa
Subclass: Hexacorallia
Order: Actiniaria
Family: Aiptasiidae
Genus: Aiptasia

Aiptasia Prevention

Unfortunately, there is no overnight cure for eradicating aiptasia. And depending on the size, it can take months to kill an aiptasia infestation. There is no dip you can use when dipping coral or live rock that will just kill aiptasia. Most people just “juice” (see “Chemical Removal” section) on a regular basis. I will get into juicing later when I cover the eradication process.

When starting a new tank or rebuilding, aiptasia-tested hobbyists will often start with dry rock, which they seed with specific bacteria and coralline algae. This has great advantages, but it can limit the tank as to what you put in it. Ocean-propagated (maricultured) corals are those least likely to have aiptasia on them. Keeping the coral or rock from transhipping (moving from one tank to the next in the chain of custody) makes it less likely for these corals to pick up hitchhikers. The downside to this is that it takes away a lot of the fun since you can’t trade with other hobbyists or club members. Why let aiptasia, or any other pest for that matter, ruin our fun? With some of the cures for eradication, these extreme measures don’t necessarily need to be applied.

Aiptasia Life Cycle and Lifestyle

Glass anemones (another common name for these pests) can reproduce both asexually and sexually, and they clone by pedal laceration. Pedal laceration is how they spread so quickly. Aiptasia do this by breaking off a piece of the pedal disc (the base or foot), which quickly turns into a polyp. When spawning, aiptasia release gametes by the millions. Once the gametes are fertilized, they become individual planula. Planulae settle on hard substrates and undergo metamorphosis into polyps. Aiptasia can also reproduce by sporing gametes or planulae while under attack. Also, a messy eater will scatter bits of aiptasia, which can lead to aiptasia blooms once the fish or shrimp is no longer in the environment.

Temperature has an effect on the sex of aiptasia. In the aquarium, they can become hermaphroditic — something not found in the wild. Temperature and light cycles affect their rate of reproduction. For aiptasia from more temperate seas, winter is their least active time, and summer is their most active time. You can reduce aiptasia breeding by almost 50 percent by lowering the temperature and reducing the lighting to reflect wintertime conditions for both variables (for some rules of thumb on keeping aiptasia in check, see the sidebar “Reining In Aiptasia”). If you choose this option, make sure all your fish and corals can survive under the desired conditions. Under laboratory conditions, a single aiptasia polyp has been shown to produce up to 5,000 clones of itself in a year!

They feed through a symbiotic relationship with zooxanthellae housed within their tissue; through photosynthesis the zooxanthellae create sugars and amino acids that provide energy for their aiptasia host. Aiptasia are also able to filter-feed by scooping up organic nutrients out of the water column with their tentacles.

They move around when they are starved of nutrition and stressed, leaving behind a piece of pedal to ensure species survival. Aiptasia can slide across substrates with their pedal or can completely detach to find more suitable living conditions. The aiptasia like to protect the pedal and will find holes and crevices on any porous parts of the rock they can quickly retract into. Great — now they’re smart! This makes it impossible for fish and shrimp to remove all of the pedal. If part of the pedal is left, the aiptasia is not dead. Aiptasia are made to survive — plain and simple.

Controlling Aiptasia

Adjusting a couple of parameters can slow the spread of aiptasia in your system, thereby making an assault on the problem more manageable. Begin by taking a tally of the numbers of aiptasia in your tank every two weeks. If the numbers remain constant over a month, temperature and lighting adjustments aren’t necessary. But if with each count the tally increases by five to 10 large aiptasia, with a lot of tiny ones besides, you may want to make some adjustments.
If you are running your tank at 78 degrees Fahrenheit with the lights on for 12 hours a day, try reducing light by two to three minutes a day and adjust the water temperature by half of a degree per week. Keep adjusting until you see a reduction in the appearance of new aiptasia. Keep in mind that if your tank is running at around 74 to 75 degrees, you can adjust the light to no less than six hours per day. Remember that this is a temporary fix to slow down the rate of aiptasia and not a permanent solution.

Get Rid of Aiptasia

Frustrated with aiptasia and with the supposed cures that don’t work and products that make it worse? You’re not the only one. Patience, my fellow reefers. Here’s the key to killing aiptasia: You must kill or remove every part of the pedal and every cell of aiptasia. You now know how and when they breed, plus what they are eating in your tank, as well as the places they like to hide. Keep trades to a minimum. Know the tank they are coming from and keep an eye out for any hitchhiking glass anemones. And practice kill at first sight. Keep nutrients down in the tank, and avoid scraping aiptasia off of your live rock, should you find it there.

Kalkwasser as Aiptasia Killer

Chemical removal. Now for the fun part: killing them. The first methods most people turn to are chemical removal (aka juicing). There are at least six products on the market that are mainly calcium hydroxide (kalkwasser). All of these work with limited success when the aiptasia is on a completely flat surface, though it is not likely you’ll find many flat surfaces in the standard reef tank. In small aquariums, these products can change water parameters by raising pH and alkalinity. All six of these products are caustic and will burn corals on contact, and if they are administered incorrectly, you risk a high probability of them not only coming back but bringing along “friends.” The problem is that aiptasia will retract to protect its pedal. And if it retracts into a hole, you most likely didn’t kill it.

You can make your own kalk paste and administer it the exact same way as the products on the market. Mix kalk with reverse-osmosis (RO) water until it has a pastelike consistency like Elmer’s glue, and then you’re ready to juice. Use a pipette or syringe to apply the paste. The best course of action is to inject the kalkwasser directly into the column of the nem. Warning: Be sure to use eye and skin protection when mixing!

Lime Juice or Hydrogen Peroxide as Aiptasia killer

Here are a few more aiptasia-killing methods to consider (there are even more on the Internet). Lime juice or hydrogen peroxide can be injected into an aiptasia’s body column with a syringe. There’s an aiptasia zapper (there are DIY and commercial versions; unless you absolutely know what you’re doing, you run the risk of electrocution with any DIY zapper) that through a reaction between saltwater and electricity creates hydrogen; when the zapper tip touches an aiptasia, it essentially turns the water in the anemone’s cells into hydrogen and effectively vaporizes the anemone. Keep in mind that whichever method or methods you decide to adopt will need to be incorporated into your regular reef maintenance and be repeated on a regular basis. If it’s one aiptasia you’re after and it’s not too big, glue it in and completely cover it with frag glue or marine epoxy.
Natural removal. Boiling hot RO water administered with a turkey baster is a “natural” aiptasia removal method. Simply fill the baster with boiling water, inject it onto the aiptasia and then suck up all the remnants in one swift motion. This boiling water method will need to be repeated on a regular basis.

Lasers are back but are not likely to be a useful tool in the removal of aiptasia. They’re not the safest for inhabitants or humans, for that matter. I tried using a 250-MW green wicked laser for five minutes with no success.

Fish and shrimp may or may not work, and if you decide to go this route there is the risk that they may have an appetite for commercial foods or your precious corals instead of aiptasia, as well as the risk that once they are no longer in your system, there will be a recurrence of aiptasia like you’ve never seen before. Fish and shrimp simply cannot get all of the aiptasia out of the porous parts of the live rock. Fish that eat aiptasia are merely controlling it. Fish and shrimp that are reluctant aiptasia eaters can be conditioned by placing them in a quarantine tank for a few weeks with aiptasia as the primary food.

Berghia Nudibranchs as Aiptasia Killers

The absolute best way to end your aiptasia troubles without adding chemicals is the “berghia” nudibranch (Aeolidiella stephanieae). (What is often sold for aiptasia control as “Berghia verrucicornis” is actually A. stephanieae.) This little guy will eat only aiptasia and hunt them down to the very last cell. Berghia use sensors on their heads called rhinophores to hunt aiptasia.

Berghia nudibranchs do their hunting at night, making them hard to see, although you can spot them using a blue LED flashlight. Like aiptasia, Berghia are asexual, so it only takes one or two of these guys to create an aiptasia-eating army. Once the white spiral egg strands hatch after about 15 days, you will have a lot of tiny aiptasia eaters. These micro berghia can and will get into the porous parts of the rock. Their life span is extremely short at only six to eight months. And once the food is all gone, the berghia die in five to eight days without aiptasia.

Berghia will not harm corals or other nems in the tank. There are a few things in the reef, however, that will prey on berghia. The number one berghia in-tank predator that may make your aiptasia eradication with berghia unsuccessful are amphipods; these will prey on freshly hatched berghia larvae. But once the berghia larvae have eaten aiptasia, these amphipods are no longer a threat. This is because the berghia co-opt aiptasia nematocysts and make them their own by incorporating them into structures on their bodies called cerata. The tip of each cerata contains a sack called a cnidosac; these hold the former aiptasia nemacysts for use on predators that might attack the berghia. When the cerata are bitten, they rupture and release the nematocysts to the surprise and discomfort of would-be predators, which in this case are amphipods. As the berghia reach full size, the threat comes from aiptasia-eating fish and shrimp. Larval berghia are too small and often inaccessible on the bottom of rocks, etc., for larger predatory fish and shrimp.

The Aiptasia Experiment

The owner of a 250-gallon tank with 300 pounds of live rock purchased an additional piece of live rock through Craigslist. Unbeknownst to him, this chunk of rock harbored aiptasia. After introduction, this infested rock eventually led to a full infestation, meaning one to five aiptasia per square inch of rock in the tank. Some of the usual name-brand aiptasia cures were employed, but these only made it worse. The tank is lit with two 400-watt radiums and eight 45-watt T5s.

Over the next few months, a raccoon butterflyfish (Chaetodon lunula) was added. It appeared that the C. lunula was successful in removing all of the aiptasia — or so it seemed. After the raccoon did its job, it was sold, and my hobbyist friend began rebuilding his reef. But one month later the aiptasia came back so thick that my friend was at his wits’ end and began tearing down his reef a second time (both times he just removed the corals).

I heard of this reef hobbyist’s troubles through the grapevine, and I decided to do some bartering with him for some of his aiptasia in return for a few berghia. I spent two days scraping as much aiptasia off the rock, glass and sand in his setup as possible before introducing the berghia. While I was scraping, I noticed the amphipod population was a little thick, so I recommended doing an Interceptor treatment before adding the berghia. The Interceptor wiped out all the pods and other inverts, making it safe for berghia to breed. The coral and fish were removed for ease of access to the aiptasia and for their own well-being (not having to deal with the ongoing aiptasia culling and removal process). When administered correctly, Interceptor (commonly used to get rid of another reef pest — red bugs) will not harm corals or fish. This process only took a month: two weeks for the Interceptor and two weeks to change out all the water. Next we added seven berghia on February 19, 2011, as all other remedies had proven fruitless. Two weeks passed with no notable changes.

Glass Anemone Eaters

Butterflyfish: Auriga, raccoon, Klein’s, longnose, teardrop and copperband are some species known to eat aiptasia and corals.

Filefish: The bristletail filefish is the only filefish known to eat aiptasia. It is not reef-safe.
Peppermint shrimp: While they eat aiptasia, they also steal food from corals and pick at zoanthids. There is a look-alike on the market called the camel shrimp that will not eat aiptasia.

The owner was flustered with the slow speed of the berghia; I told him this was no overnight cure but that we could increase the number of berghia to speed up the process. I added 23 more berghia on March 5, 2011, for a grand total of 30. Two more weeks passed, and there was little to no change in the tank. The owner was disappointed and ready to tear down the reef completely and start over. I convinced him to wait two more weeks. On March 22, I received a call telling me there was an aiptasia missing, and I told him to look around to see if any more were missing. Since he looked at the tank daily, it made it hard to spot progress. I had inspected the tank and added 14 more berghia on March 19, 2011. There had been a noticeable improvement since the initial introduction of berghia one month prior. I kept in close contact with the owner over the next few weeks.

By April 16, 2011, the aiptasia population had been reduced by half, and the owner was becoming optimistic; it seemed as if a weight had been lifted off his shoulders. The hatch rate of the berghia must have been phenomenal, as 16 days later (May 2, 2011) there was no sign of aiptasia, and berghia scoured the glass after lights out. I went over to his house for a BBQ and collected as many berghia as I could to find new homes for them.

The owner and I are fairly close friends now. I see his tank on a regular basis — it remains aiptasia free.

By: Chewy Editorial

Featured Image: Via Matthew and Jessica Reed, Reef Pest Solutions



By: Chewy EditorialPublished:

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