Claire Corlett

Fish Food, Fish Tanks, and More
Top 5 Pests in Reef Aquariums

Top 5 Pests in Reef Aquariums


What’s up everyone, this video is all about
hitchhikers… mainly the top five that suck. Hitchhikers make their way into home aquariums
by stowing away on pieces of live rock and coral. Some are relatively benign such as
the occasional feather duster worm. There are even highly sought after hitchhikers such
as commensal hermit crabs that live in some stony corals. This video however is not about
those types of hitchhikers. In this article we will discuss my top five most problematic
pests. Before addressing my top five, there are pests
that are going to be noticeably absent, so let’s go ahead and give out some honorable
mention awards. These pests can be annoying and prevalent but just didn’t quite make
the cut for one reason or another. First on the list of honorable mentions is
Aiptasia. If you’ve never had them before, don’t worry, it’s just a matter of time.
They are extremely prevalent in the hobby and are a huge nuisance mainly because they
have great survival skills and they like to sting nearby corals. Aiptasia didn’t quite
make the top 5 because they can be managed effectively by the introduction of certain
fish such as copper band butterflies, peppermint shrimp, or Berghia nudibranchs. Their predators
are so effective at eliminating Aiptasia the concern quickly turns to whether they might
starve once the job is done. Also, while they pack a potent sting and can stress nearby
corals, the damage they cause is relatively tame compared to the pests that actively feed
on the corals in the aquarium. Similarly, Majano anemones don’t quite make
the cut because it is possible to eliminate them entirely if caught early by manual removal.
They do not have a particularly tight grip on their substrate and can be worked off the
rocks and siphoned out. In tanks with medium sized populations, one can remove the rock
work entirely and sit the rocks outside for a week or so to kill all the anemones. The last honorable mention award goes to bristle
worms. They get a bad wrap most of which is pretty unfair. Bristle worms are a diverse
group of invertebrates. Many are harmless and even make amazing detritivores that help
the reef aquarium process uneaten food. It is for this reason that bristle worms are
not in the top five. It is only a small minority that can cause trouble, and those can be found
and removed, especially if we are talking about a large predator like a hobbit worm
for example. If you do this hobby for long enough, it becomes
routine to manage the low level pests that show up here and there. Over time, you learn
new techniques to help mitigate the risk of hitchhikers, and sometimes a new product comes
on the market that helps with a particular pest. All that is great! After a while though,
something happens that I like to refer to as the Batman problem. Bear with me for a
second. A long running theme in the Batman story line is the question whether Batman
is actually good for Gotham City. On one hand, he cleans up the street by fighting crime,
but that in turn creates a vacuum that draws in even more dangerous criminals. As time
goes on, only the most violent and most deranged super criminals are left. That’s kind of
what we do here. We eliminate the gangsters and petty criminals in our tanks and then
comes the Joker, and now we have some serious problems the might take some extreme measures
to handle. So after all that hype, let’s take a look at the top five! Number five… Red Bugs. “Red Bugs” are
small crustaceans that infest Acropora colonies. I liken them to fleas that irritate the coral
and eventually causes polyps to stop extending fully. A greater concern is the potential
for die-off which can lead to the loss of the whole colony. Acropora are a sensitive
species and the colony can go down hill in a hurry. Red bug issues are difficult to diagnose because
of their size. It is very difficult to see one of these specimens unless you know what
to look for. They appear as small red dots on the skin of the Acropora colony. One trick
to seeing them is to stare at a small portion of the Acropora and just pay attention to
anything moving on the smooth surfaces. It gets easier to see them with some practice. Red bugs are resistant to many of the commercially
available coral dips on the market, which is odd because dips in general seem highly
effective against most other crustaceans. Some hobbyists report having success using
a dip in either Interceptor, a prescription pill for heart worm disease in cats and dogs
or Bayer Advanced Insect Killer which you can find at a hardware store. This dip is great when you can remove the
infected colony from the tank however in some cases the colony is too large to remove safely
or has grown onto the rocks. In this case, you might consider using a product called
levamisole, a commercial pig dewormer on the entire aquarium. Remember when we talked about
drastic measures? This is a drastic measure. It is absolutely brutal on many of the tank’s
inhabitants. It will kill all the beneficial inverts in the aquarium and it is going to
stress out fish like you wouldn’t believe. It may be a good idea even to try and catch
all the fish and inverts and relocating them to a quarantine system for a few days. Luckily, there is another method of dealing
with red bugs in an established tank where the Acropora cannot be removed. Dragonface
Pipe Fish are a close relative of sea horses and act as a natural predator of the crustaceans.
They are surprisingly adept swimmers and constantly pick off microorganisms. Ok, let’s move on to #4… Sticking with
Acropora pests, we have Acropora eating flatworms. These guys can be tricky to see, so often
it’s not possible to catch the problem early. One day, you might see these white speckles
show up on Acropora and then you know you have an infestation. Those white speckles
are the bite marks from where the flatworms were eating the coral, and there is a good
likelihood that they are all over the coral. There is some good news and some bad news.
The good news is, these flat worms can be removed by dipping. The flatworms let go of
the host coral. In some particularly bad cases of flatworm infestation, what you thought
was a brownish-tan colored Acropora was actually a white Acropora that was covered with hundreds
of flatworms. Yeah… that was the good news. The bad news is, removing the adults probably
won’t eliminate the infestation because they lay eggs and those eggs survive almost
every dip. It may take weeks of diligent dipping to fully cure a colony. Let’s move on to #2. Zoanthids on one hand
are one of the easiest corals to keep in the reef keeping hobby. On the other hand, they
are also one of the most susceptible to a wide range of pests. One such pest is the
Zoanthid Eating Nudibranch. This variety of Nudibranch was particularly well disguised
because as they eat the Zoanthids, they take on the color and fluorescence of the polyps.
After a while, they look just like another head in the colony. Here is one that’s been isolated. These
nudibranchs can be removed by dipping in commercially available dips but like the Acropora eating
flat worms, their eggs survive and can be very difficult to remove. The eggs form a
spiral pattern and have a thick gel coat making them difficult to remove with metal scrapers
and brushes. What seems to work better is a dry paper towel. The paper towel dries out
the gel coat and are coarse enough to pull them off the polyp. Despite the effectiveness of dipping to kill
the adults and physical removal of the eggs, an infestation of Zoanthid Eating Nudibranchs
is still difficult to manage because unlike many pests that only stick to the coral, these
pests are perfectly comfortably roaming the tank looking for new colonies to eat. Even
if the hobbyist was diligent and purified every single zoanthid colony, it is likely
these sea slugs are still hiding somewhere in the rock work and can reemerge later. Ok Number Two! If the nudibranchs weren’t
bad enough there is a second pest that plague Zoanthids and is the stuff of nightmares.
There is a variety of sea spider gobbles up Zoanthid colonies. If you are familiar with
the Alien movie franchise, these sea spiders are the face hugger aliens of the reef aquarium
hobby. They latch on to the Zoanthids at the mouth of the polyp and lay eggs inside the
polyp. Later as the spiderlings hatch the polyp disintegrates in to a grey mess. I’ve isolated one that I found a long time
ago. They are super creepy and can cause wide spread damage so if you see your zoanthids
staying closed for extended periods of time and turn to mush, take a close look for these
guys. These sea spiders can be physically removed
with tweezers and dental tools. Commercially available pest control dips are also effective
at killing them if given enough time in the bath. The eggs however are completely unaffected
by either method of removal because they reside deep within the tissue of the polyp. It takes
several rounds of removal to get rid of a spider infestation and can be a frustrating
process especially because during this whole time the Zoanthid collection looks like it
is dissolving before your very eyes. It’s time for number one. It’s the Montipora
Eating Nudibranch and the bane of my existence. They are one of the most difficult pests to
manage and are frequently imported on wild colonies. They are so bad in fact that I now
consider discarding a coral infested with them rather than trying to eradicate the nudibranchs.
The Montipora Eating Nudibranch is white in color and tiny compared to the Zoanthid-eating
variety. They can be difficult to spot at first because they tend to start working on
the bottom of the colony. Removal of this variety of nudibranch is more
challenging than any other I have had the displeasure of dealing with. First off, they
are resistant to dipping. The adults do succumb in time to an aggressive dose but can shrug
off most regular concentrations of coral dip. The eggs are difficult to remove and require
scraping of the coral’s skeleton to dislodge. Even with careful extraction of the eggs,
they are small enough that many go undetected only to hatch later. This past year, we attempted sequential dips
to where we dipped certain corals over 50 times. In the end, the nudis seemed to disappear
but then once summer came along they reappeared suddenly. Given their persistence and considerable
damage they are capable of, the Montipora Eating Nudibranch is a top tier pest in the
hobby today. Hitchhiker pests unfortunately are a reality
in the reef keeping hobby. As a conscientious hobbyist, one can never ever assume that a
coral or rock is clean because it comes from a seemingly good system. Developing a systematic
approach to new coral introduction is worth its weight in gold if it successfully prevents
just one outbreak. Some combination of preventative dips and quarantine will help immensely as
will purchasing from aquacultures sources as those corals are more likely to have undergone
dipping themselves. Ok, that in a nutshell is my top five list of horrible pests. Let
me know if you agree or disagree and list your worst in the comments below.

100 comments on “Top 5 Pests in Reef Aquariums

  1. At 11:42 what are those white little egg things moving? Are those harmful because i have them in my reef and been noticing some of my zoas disappearing. Please respond because i haven't found any info about them till i was your video.

  2. And this is why if I do decide to get tropical reef tank I'm going to use fake corals instead of the real thing. That way I won't have to deal with these pests.

  3. I have a long big white flat – worm, just discovered it, trying to figure out what it is and how to remove. I don't have any corals but I plan on getting some. I also have aiptasia and bristle worms. All in one rock.

  4. I found out about zoanthid eating nudibranchs the hard way. Then I dipped my colonies and bought a yellow Coris wrasse. Haven't seen any since, and the zoanthids so far (knock wood) look good.

  5. I use to think sea slug are cute little critter.
    Until i see this video and realize they eat poly……………

  6. What is your take on Hydroid Jellyfish? I have them completely covering my glass. I scrape them off, and they land on corals, and irritate them.. They have been growing in number for about a month.

    Ideas?

  7. I just found a white slug With blue line down the belly and Bluetip. With some where looking feathered legs and feathered antenna. Anybody know what it is?

  8. That Bobbit worm you mentioned sends chills up my spine. I hope I never cross paths with the liking of them. Bubble algae are the biggest pain. I've been fighting an infestation for almost 3 months now and they just won't go away. Any tips? I do manual removal and I have hermit and Emerald crabs that are helpings, but at the end of the day they turn to eating whatever is left of the fish feed.

  9. I just started my tank a week ago and today after the water change I found some kinda sea slug thing that I do not know if it's a pest or not.

  10. I've recently gone bare bottom an removed all the sand. It has made a world of difference. All pests are down and no more spikes. Most uneaten food a debris is now sucked up and removed by the filter.

  11. I found these things that look like individual white air algae with a white tip. Later learnt these are hydroids. Help me!!!!

  12. Nudibranchs seem to need extra time in a dip to kill! What has worked for me is 1. Dipping 2. Manual removal! Use tweezers and really look hard using bright light and even magnifying glasses. 3. Remove eggs!!!! This is the most important step. Do this every week for a few weeks and then again a couple weeks after that just to check again. Then AGAIN in a month. I've wiped mine out this way and never saw them again.

  13. where can i buy a zoanthid eating nudibranch, and how large a zoanthid colony would i need for a nudibranch/zoanthid tank? i think they are cute

  14. ill be starting several types of tanks soon after i move. A nudibranch tank (1) a coral reef (2) and food breeding tanks for the things i can aquaculture for my aquariums. so i was just wondering

  15. Levanmasol is used alot to deworm fish by putting it in their food. Its heavy duty stuff. Are these red bugs crustaceans or worms? Would shrimp eat them, since certain cleaner shrimp will actually eat parasites off coral and fish?

    Also what about temperature control? With certain freshwater parasites raising or lowering the temps to certain extremes can "Assist" in eradicating the parasites while only stressing the host. Has anything every been done with this in marine, with things like the spiders or slugs? Im just getting into marine from fresh so I find this interesting.

  16. I had a seemingly rare infestation of acropora and porites eating sea spiders (and probably montipora eating too). At night, if a flashlight was shined in the tank, they could be seen covering every single sps coral remaining. Only thing that killed them was direct exposure to ozone, but that killed many corals too.
    Ended up taking my purple monster acro, so they are forever my enemy.

  17. No hard corals for me!! I would freak out seeing any type of bug. I am not new to fish keeping, but I AM new to the saltwater hobby. Just watching this has me itching. ewwwwww

  18. I am just looking for a couple opinions, do u think that I can get away with a powder blue tang in a 4foot long tank?

  19. That's bad! When you spend hundreds if not thousands of dollars invested into some corals that you take so much pride in only to have them killed by some pests. And the eggs survive any commercially available dips so basically you can't do anything to avoid it?

  20. I really wish you would do a video on Vermetid snails. I recently had 1 head on my frogspawn shrink to almost nothing then I noticed a vermetid on it….. I removed the snail and the head has recovered almost fully. I cannot find much info on this pest and I'm sure you have the knowledge! you rock Than

  21. well this is good to know i just started a tank and one of these aptasia i know im butchering the name but one of them came in on my live rock that i bought

  22. This is why I make my own live rock. With rocks from outside! I only use live sand. And I get free Caribbean shells with my sand!

  23. I was so enthusiastic about getting a saltwater aquarium. Now after watching this video I feel like I don't want it anymore.

  24. When I first got my tank, I noticed a white aphasia on one of my live rocks, it hasn’t moved or done anything so I’m just going to keep it there. Hasn’t moved in atleast 3 years

  25. These arent exactly reef pests, more like pests that are associated with only 2 types of coral, neither of which are in my tank so from what I gather, these top 5 will never be in my tank? Is that right or am I missing something?

  26. I’m surprised that vermited snails didn’t make the list, any recommendations on getting rid of these or anything that will eat them?

  27. OK long shot but does anyone know the name of the Acro at 4:05 – 4:12, I just bought an unnamed frag that looks just like it, thank's.

  28. Just got Monti eating nudis in my tank ….haven't added anything new in like a year so these are decent sized colonys of many variety….thinking Bayer but idk ….he says just toss the coral ….that'd be half my tank

  29. I have some bristle worms in my aquarium and I love them they are great scavengers people should research them before judging them.

  30. "Let me know" — but who is "me"? If you make the video anonymously without introducing yourself for privacy reasons to avoid publicity, it is better to not use personal pronouns. Otherwise, the video is great.

  31. How could anyone give any of your videos a thumbs down. You are a scientist with this stuff! Talk about an expert!

  32. Angelfish can eat nudibranchs just wondering would be a good choice to keep that pest in checked also what would eat the spider pest thanks keep the videos going i am learning so much from them

  33. I found a worm in my rocks and I freaked out and pulled the whole rock out and got it out and now I feel bad?!!! Wtf

  34. Lol i got some live rock from petco, brought it home and rinsed it thoroughly. Quarantined it for a while. Finally put it in my tanks and guess what? Random bristle worms that are way too hardy apparently survived and i found 2 😂 ah well

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