Aiptasia Eating Filefish (acreichthys tomentosus)

Dear Debi:

Under the circumstances, I think you have the right idea to control the Aiptasia rock anemones biologically rather than chemically, Debi. Often the chemical treatments that can eliminate Aiptasia anemones have an unfortunate side effect – they trigger the anemones to release spores before they die, with the result that the Aiptasia eventually reappear with a vengeance in the weeks following the chemical treatments.

A bristle-tail file fish is one option for biological control you can consider, but it’s often not the best option for eradicating Aiptasia anemones in a dedicated seahorse setup, just as you surmised. I would prefer a small colony of decorative shrimp (e.g. Lysmata wurdemanni or Rhynchocinetes species) that will eat Aiptasia rock anemones (if it’s a light infestation) or a group of Berghia nudibranchs to control the Aiptasia if you have a heavy infestation of the anemones.

You can try a file fish of the right type to control Aiptasia rock anemones if you wish, Debi, but proceed with all due caution if you decide to go that route. There are a few things that you must keep in mind, if you do so, Debi.

First of all, not all file fish will browse on me Aiptasia rock anemones, but ALL file fish definitely do like the taste of the frozen Mysis that you will be feeding the seahorses, so there is bound to be some competition for food, but with one small file fish that should not be an insurmountable obstacle by any means. The bristle-tail file fish (Acreichthys tomentosus) that you mentioned in the subject line for this message is the only species I know of that definitely eats Aiptasia glass anemones, Debi, so make sure that you get the right file fish to do the job!

Secondly, although file fish sometimes do well with seahorses, they do often have a tendency to be fin nippers and there is a very definite possibility that your file fish might be one of those individuals that develops a bad habit of going after the dorsal fins of the seahorses. Because of this distinct possibility, if you do try a file fish to help get the Aiptasia rock anemones under control, it would probably be best not to plan on having the file fish be a permanent resident of the tank. By that you mean that I would relocate the file fish to one of your other aquariums (or return it to the pet store where you purchase it for store credit) once it has whittled down the Aiptasia population to manageable proportions. I would then install a small colony (3-5) of peppermint shrimp (Lysmata wurdemanni) or dancing shrimp (Rhynchocinetes durbanensis), both of which are outstanding Aiptasia predators that thrive in small groups and that do very well with seahorses, in order to keep the Aiptasia rock anemones under control from then on…

Thirdly, you’ll need to make certain that the file fish you obtain is 100% healthy before you introduce it to your seahorse tank to make sure that you won’t be exposing the ponies to any pathogens or parasites that the file fish may be carrying. Ideally, you would quarantine the file fish for 30 days to assure that it’s a healthy specimen, so proceed accordingly.

If you bear those precautions in mind, then a bristle-tail pipe fish could possibly be helpful for this problem, but you would be taking a chance…

Personally, I think I would go with the small colony of peppermint shrimp (Lysmata wurdemanni) or dancing shrimp (Rhynchocinetes sp.) right from the start for biological control of the Aiptasia if you are talking about a light to moderate infestation of anemones since you can be confident that, as invertebrates, the shrimp won’t be carrying any pathogens or parasites that might pose a risk to the seahorses.

Or, if you’re confronted with the heavy infestation of the anemones, then I would suggest that you acquire several of the small Berghia nudibranchs to control the Aiptasia instead. The Berghia nudibranchs are obligate predators of Aiptasia anemones, meaning that they are specialized feeders and that the Aiptasia anemones are the only thing that they will eat. If there are only a few Aiptasia anemones in your seahorse tank, that’s not enough to support Berghia nudibranchs which MUST have the Aiptasia available to feed upon or they will starve to death.

On the other hand, if they find abundant Aiptasia anemones, the Berghia nudibranchs will reproduce in the aquarium to deal with the abundance of food.

In your seahorse setup, a small group of peppermint shrimp (Lysmata wurdemanni) or dancing shrimp (Rhynchocinetes sp.) should be able to effectively eliminate a few stray rock anemones with no problems, so that would be my choice for your 20-gallon tank.

Also, Debi, I should mention that you don’t want to include both the predatory shrimp and the Berghia nudibranchs in the same tank, because the peppermint shrimp or dancing shrimp may feed on the nudibranchs as well as the anemones. So pick one or the other, depending on the type of infestation you are dealing with; for the heavy infestation in your seahorse tank, that’s an excellent situation for the Berghia nudibranchs to clean up, whereas for a light infestation of Aiptasia rock anemones, the peppermint shrimp or dancing shrimp are a better choice. (That’s because once the shrimp have taken care of all of the Aiptasia anemones, they will happily make a living by scavenging on leftover Mysis and other organic wastes, whereas the Berghia nudibranchs would simply starve to death.)

Read through the following article carefully, Debi – it will explain all about what make Berghia nudibranchs such effective Aiptasia Anemone predators as well as how to care for them and acclimate them to your aquarium properly:

http://www.saltyunderground.com/pages.php?pID=23

Okay, Debi, that’s the rundown on the Berghia nudibranchs.

If you haven’t already done so, be sure to check out the following online article as well, Debi, because it has some excellent suggestions for controlling Aiptasia glass anemones that you may find helpful:

http://animal-world.com/Aquarium-Coral-Reefs/Aiptasia-Pests

Best of luck getting your Aiptasia rock anemones problem under control.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support

Dear Debi:

Actually, I believe that your cleaner shrimp would not present a problem for a small colony of peppermint shrimp, Debi. I know a number of hobbyists who keep decorative shrimp – scarlet cleaner shrimp (Lysmata amboinensis) and/or fire/blood shrimp (Lysmata debelius) – together with the popular peppermint shrimp (Lysmata wurdemanni) in their seahorse tanks without any problem.

The reason they are normally able to coexist without any conflicts or aggression is that the shrimp divide up the available resources chronologically, with the cleaner shrimp being on the clock diurnally, manning the day shift, while the nocturnal peppermint shrimp take over after dark, working the graveyard shift. So you will find that your cleaner shrimp are out and about during the day, cleaning up leftover Mysis and scraps from the seahorses’ messy meals, Debi, while the peppermint shrimp are resting in their favorite hideouts, whereas the peppermint shrimp take over after dark (when the cleaner shrimp are no longer active), working the night shift.

So I think a small group of 3-5 peppermint shrimp (Lysmata wurdemanni) would do well in your seahorse tank together with the large cleaner shrimp, Debi. The cleaner shrimp would police the tank during the day, mopping up leftovers from your seahorses, and the peppermint shrimp will scour the tank after dark, chowing down on me Aiptasia rock anemones. That’s a good way for the shrimp to divide up the available resources because the cleaner shrimp will have no interest in the Aiptasia rock anemones, and even though there may be no leftover Mysis for the peppermint shrimp eat during the night, they will happily predate the Aiptasia rock anemones that are shunned by the cleaner shrimp.

The other discussion thread you found is largely correct about Aiptasia glass anemones not causing any harm in a fish-only tank, Debi. Aiptasia rock anemones and majano anemones are mainly a concern for reef keepers, who don’t want them to crowd out or out-compete their live corals. The Aiptasia and majano anemones are not typically a concern in fish-only aquariums (with the exception of seahorse tanks, of course) since the anemones do no harm at all to most fish and may even provide a welcome dietary supplement for butterflyfish and angelfish.

Of course, a dedicated seahorse tank is the exception to the rule that Aiptasia rock anemones are not harmful in fish-only aquarium systems, Debi. That’s because the seahorses face a much greater risk of being stung and suffering damage to their integument from anemones than free swimming fish such as tangs or damselfish or just about any marine tropical. The reason for this is that seahorses are demersal animals that orient to the substrate and habitually grasp convenient objects on the bottom with their prehensile tails. This is going to inevitably bring them in contact with any anemones or live corals or sessile invertebrates you keep in the aquarium, so it’s important to avoid anemones and to limit yourself to soft corals and certain select SPS corals or LPS corals that cannot harm the seahorses when they grasp the corals with their tails.

Seahorses are smart and they will learn to avoid an anemone or stinging coral once they’ve come in contact with it. The risk involved in keeping cnidarians with seahorses is therefore twofold, Debi: (1) the risk that they will be badly stung during that first contact before they realize the anemone is a danger, and that their injury may allow secondary infections to take hold where the integument has been damaged, and (2) the risk from pest anemones (Aiptasia or majano) becoming so numerous that they cannot easily be avoided and that the seahorses repeatedly blunder into them (perhaps after dark or when an unpredictable current whisks the seahorse against the nematocysts). So the greater the number of the anemones confined with the seahorses within a limited amount of space, the greater the risk that they will eventually be severely stung or repeatedly stung, to their detriment.

That’s where the other discussion thread you came across is dead wrong in my opinion, Debi. In my experience, the population of Aiptasia anemones in an aquarium is NOT self-regulating or self-limiting whatsoever. Quite the contrary – they grow like weeds, can reproduce asexually as well as sexually, and can quickly take over an aquarium by sheer numbers. They are not like hydroids, which only become pests in nursery tanks or dwarf seahorse tanks that are receiving daily feedings of newly hatched brine shrimp (Artemia nauplii) that are suitable for filter feeders. The Aiptasia anemones spread by fragmentation and can regenerate an entire individual from a single cell. Aiptasia anemone contain zooanthellae (symbiotic algae cells) and their tissue that give them the ability to produce food via photosynthesis, and they also capable of absorbing nutrients from the aquarium water. So please don’t rely on the Aiptasia anemones to control or limit their own population – that ain’t gonna happen, and if they have favorable conditions, they will quickly take over an aquarium.

In short, I would take some means to control the Aiptasia anemones in your seahorse setup as soon as possible, Debi, and I would favor biological controls over chemical controls in most every instance. In your case, I think the peppermint shrimp (Lysmata wurdemanni) would be a very good option. Your large cleaner shrimp, which are active during the day, will clean up all of the leftover Mysis so that your peppermint shrimp will not be able to satisfy their appetite with gourmet Mysis shrimp when they come out after dark to work the night shift for your cleanup crew. Deprived of juicy Mysis by the daylight scavenging on your cleaner shrimp, the nocturnal peppermint shrimp are bound to resort to chowing down on any of the smaller Aiptasia anemones in the tank, thereby helping to control them.

The peppermint shrimp will often avoid really large anemones – greater than an inch or two in the diameter of the oral disc – but you can take care of the biggest Aiptasia anemones yourself by administering lethal injections, Debi, and between you and the peppermint shrimp, you should to have the Aiptasia infestation under control.

Good luck!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support

Dear Debi:

Yeah, I’m beginning to think you may be talking about something other than Aiptasia rock anemones, Debi. If they are all so small that you need a magnifying glass to get a good look at them, they may well be something else altogether.

Aiptasia rock anemones are easily visible with the naked eye, and the larger specimens will have an oral disc with a diameter in excess of 1-2 inches. Likewise, the Majano pest anemones are even larger and more difficult to eradicate.

Judging from your description, it’s clear that your little pests with the retractable translucent stem and milky crown are cnidarians, and they are almost certainly hydrozoans of some sort, Debi. But their size suggest something other than Aiptasia glass anemones; if I had to make a guess, I would say you are most likely dealing with some sort of polypoid hydroids.

If that is indeed the case, it would be good news, Debi, since the hydroids are only problematic for the miniature seahorse species such as dwarf seahorses (Hippocampus zosterae). The dreaded ‘droids pose no threat to the larger seahorse species such as Ocean Rider Mustangs and Sunbursts (Hippocampus erectus) and, unlike Aiptasia anemones, hydroids should not undergo a population in a tank like yours.

Hydroids typically only get out of hand when they are in an aquarium that is receiving daily feedings of copepods or newly hatched baby brine shrimp (Artemia nauplii), which the hydroids require in order to thrive. Those are conditions that we normally only find in nursery tanks or dwarf seahorse tanks, so if you’re pests are hydroids, they should remain in small numbers and you needn’t worry about controlling them or eliminating them. But you should try to verify their identification, since there are so many different types of hydroids and they can appear vastly different depending on their stage of life and their diet.

The unexpected appearance of various crustaceans and microfauna in a SHOWLR tank is the very reason aquarists refer to these rocks as "live." It can be very difficult to accurately identify all of the mysterious life forms that may blossom from your live rock over the months and years, Debi, but 99% of them are harmless, benign, or beneficial to the aquarium and the pageant of life that appears in microcosm from the LR is fascinating to observe 100% of the time.

There are really only about four types of undesirable hitchhikers that sometimes sneak into our tanks concealed amidst the live rock or upon live sponges or live corals and which are problematic for large seahorses like Mustangs and Sunbursts, Debi, as outlined below:

(1) mantis shrimp;
(2) predatory crabs;
(3) fireworms and bristleworms;
(4) Aiptasia rock anemones, a.k.a. glass anemones.

With the exception of the four undesirable pests mentioned above, most anything else that emerges from your live rock or live sand will be benign or even beneficial for your aquarium, Debi, so you needn’t be too concerned at this point.

Reef Central (http://www.reefcentral.com/) is the place to go to identify all of the interesting critters that pop up from live rock or live sand or natural seawater. They have an excellent series of photo galleries on their site, including one devoted to Reef Tank Hitchhikers, so you might check in there and see if any of their photos look like the small anemone-like translucent white polyps you are worried about:

http://www.reefcentral.com/gallery/?s=a568b6f0af1e82b52aaa9cce5f4f27be&menu=5

Reef Central has a discussion forum devoted just to seahorses, so it’s a good place to visit from time to time anyway.

Also, if you copy and paste the following URL into the Web browser on your computer, it will take you to another site with lots of photographs of aquariums hitchhikers that may help you to identify your mysterious tiny white bugs:

http://www.chucksaddiction.com/hitchhikers.html

Let me know if you find any photos that look like your tiny milky white polyps with the translucent retractable steps to verify their identification, Debi (look closely at the photos of any hydroids anemones or polyps, in particular), and I will be happy to advise you whether they are harmless or should be removed from the aquarium.

Best of luck identifying your ministry hydrozoans, Debi!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support