How To Get Rid Of Bristle Worms: Guide | Aquascape Addiction

How To Get Rid Of Bristle Worms: Guide

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If you want to know how to get rid of bristle worms then this guide will help, it covers everything you need to know and more.

How To Get Rid Of Bristle Worms: Guide

Having an aquarium is without a doubt one of the best things to have in your home, with fish being some of the coolest pets you can possibly have. However, what happens when you have more creatures in your aquarium than you bargained for? One of the creatures that may appear in your aquarium, one that is totally undesirable to say the least, is the bristle worm and this post covers why they are bad, how to find them and most importantly how to get rid of bristle worms.

The bristle worm is a giant nuisance that many reef aquarists have to deal with and they are a big problem no doubt. These little buggers can cause some serious damage to your reef aquarium. So, let’s get to it and find out everything there is to know about these pests, and of course we are going to give you some foolproof methods for getting rid of them.

What Is A Bristle Worm?

The bristle worm has many different scientific names depending on the exact species in question, but the name is not all that important. For all intents and purposes you can just call it a nuisance, because there is probably no more of an accurate word to describe these pests than a nuisance.

Bristle worms are free-living segmented worms with long bodies, free-living meaning that they can technically be cut in half or multiple parts, and each of the parts could survive and grow on its own. The have long appendages at the front by their face, kind of like fangs on a spider, and their length is adorned with tufts of bristles. Don’t be fooled though, because while the bristles may look like the soft ones you would find on most caterpillars, the bristles on a bristle worm are hard and sharp, more like small porcupine quills than anything else.

The most common bristle worms that can be found in reef aquariums will be anywhere from 0.5 to 2 inches long and are usually pink in color. There are however larger ones out there, with the largest ones being able to reach 2 feet in length. Also, the larger bristle worms tend to be more reddish and brown than pink, or even gray too. These little buggers like to live in and under the substrate, or under rocks and other objects as well.

Why Are Bristle Worms Bad?

There are actually a few different reasons why you really do not want to have any bristle worms in your reef tank. The first reason why bristle worms are bad is because of the bristles themselves. The bristles are very hard, sharp, and fairly long. This means that any contact they make with other fish or creatures in your aquarium can result in disastrous consequences.

Cuts, scrapes, and bristles stuck in your fish are just the beginning. Fish are fairly sensitive to bacteria in the water, and once they have an open wound, like one caused by a bristle injury, developing illness is not far away.

Another reason why bristle worms are such a nuisance is because they can indeed be predatory, and they are also a formidable opponent for some smaller animals, especially the large bristle worms. That being said, bristle worms are usually not aggressive or predatory, but that is truer for the smaller ones than larger ones. Larger bristle worms have been known to be predatory and attack other animals. The result may be that a large bristle worm might try to kill everything in sight and take over the aquarium. Larger ones even have pretty big jaws that they can use to bite other fish and you.

Next, bristle worms are usually known to be scavengers and they will eat any foods missed by your fish. If your fish are slow eaters, the bristle worms may actually steal their food, thus leaving them underfed. Moreover, bristle worms also produce waste just like any other animal, and this means that the aquarium filter you have will need to be cleaned more often than without bristle worms.

Finally, these little pests can multiply very quickly. You might only have seen 1 or 2, but chances are that you have far more of them present. Also, you don’t want to be cleaning out your fish tank and feel a sharp pain either. The bristles on smaller bristle worms can get stuck in your skin and sting real bad, not to mention that larger ones can indeed bite you.

How Do They Get In?

The only real way that bristle worms get into your tank is when you buy plants, rocks, or coral and they are already on it. Therefore, a good way to prevent them from getting into your aquarium is to thoroughly check and rinse off anything that is to be put in your reef tank before putting it in.

Finding The Bristle Worms

You might have caught a glimpse of a bristle worm in your reef tank, but you just aren’t sure. This is of course because they don’t like light, they get scared of light and movement, and they like to live under things in general. There are however a couple methods you can use to see if there are any bristle worms in your reef tank, but they do take some time.

How To Catch A Bristle Worm

To be clear, bristle worms are nocturnal animals, so you probably won’t see them during the day anyway. Moreover, they are scared of light and quick movements, so simply waiting for nighttime and using a flashlight will only scare them away. The only thing that you can really do to make sure whether or not you have bristle worms is to close the curtains, turn the lights off, and wait. After a few hours of dark they should start to wander around your reef tank.

Of course it is now dark so you still won’t be able to see them. For one reason or another, they don’t seem to mind red light. So, get a flashlight, cover it with some thin red plastic to make the light red, move very slowly towards your aquarium, and use the red light to inspect it. This should reveal any bristle worms that are roaming around your reef tank.

How To Get Rid Of Bristle Worms

There are a few different methods that you can try in order to get rid of any bristle worms in your reef tank, so let’s go over the most effective ones for bristle worm removal.


One thing that you can do to get rid of bristle worms is to buy predators that will eat them. Both Coral Banded Shrimp and Arrow Crabs have been known to eat bristle worms, at least the smaller worms. Also, dottybacks, wrasses, goatfish, and several other fish are known to eat bristle worms. This is a good solution if you have a few smaller bristle worms, but will not work for larger ones as the table may turn and the worm may eat the shrimp and/or crabs. Also, keep in mind that getting predators to eat the bristle worms also means having a more diverse aquarium with more critters to care for.


Another way to get rid of bristle worms is to simply buy bristle worm traps at your local pet or fish store. Put the traps in the bottom of the tank, but some bait in them such as cooked shrimp, raw scallops, clams, and fish, and wait for the traps to fill. Wait for 24 to 48 hours and see if the trap has caught anything. You can then remove the bristle worms and dispose of them as you wish.

You can put them in a separate tank if you wish, donate them to a pet store, or if you really need to, killing them is always an option, but it really is a last resort. Keep in mind that it may take you a while and some trial and error to find a trap that works. You can always try making your own homemade traps, but that is difficult, and when you consider the time and materials needed to make a trap, you are probably better off buying one.

Hollow Rocks

Another method to get rid of bristle worms is to use a rock with a hollow on the bottom, place it on the substrate with some bait in the hollow, and just wait. Come back in the morning and quickly lift the rock. If you have bristle worms they should be in the hollow of the rock or just under the rock. This will take some skill because they are pretty agile, so you need to be ready with the net when you lift the rock or else they will get away and go hide somewhere else. Remember not to touch them with your hands because that will definitely not feel too nice.


Bristle worms are definitely a nuisance for any reef aquarium. They can cause a whole lot of trouble and they hurt to touch as well. However, with the above methods, or a combination of them, you really should have no trouble getting things under control.