Vermetid Snails 101: Everything You Need to Know About These Coral Killing Worms and How to Eradicate Them

| Updated: July 13, 2023
Vermetid snails pest in saltwater coral reef aquarium tank.

Hey there, fellow reefers! Let’s discuss one of the most annoying and destructive pests that can plague your coral tank: vermetid snails. You may have seen these little buggers in your tank, or maybe you haven’t, and you should count yourself lucky. They look like tiny tubes or worms sticking out of your rocks or corals, and they shoot out sticky webs of mucous to catch their food. Sounds gross, right? Well, it gets worse.

These vermetid snails can also harm your corals by smothering them, competing with them for space and nutrients, and blocking their light and water flow. Not cool, vermetids, not cool at all.

So how do you get rid of these pesky pests? And, more importantly, how do you prevent them from entering your tank in the first place? That’s what I’m going to show you in this article. I’ll teach you how to recognize vermetid snails, how to remove them safely and effectively, and how to keep them away from your beautiful corals. Trust me; you don’t want to miss this. Vermetid snails are no joke, and they can ruin your reef if you let them. So let’s get started and learn how to deal with these wormy invaders!

How to Recognize Vermetid Snails

One of the first steps to dealing with vermetid snails is to know how to spot them. These snails are sneaky and can blend in with your rocks or corals (when small), so you may have to look closely. Vermetid snails have irregular tubular shells that can be straight, curved, or coiled. They can be white, brown, gray, or even purple, depending on the type of substrate they attach to. They usually grow in clusters or colonies, and they can reach up to an inch in length.

But the most distinctive feature of vermetid snails is the web-like mucous nets that they use to catch their food. These nets are sticky and can cover a large area around the snail’s opening, which is usually facing upward. You may see these nets floating in the water or attached to your corals or other tank inhabitants. If you see these nets, you can be sure that you have vermetid snails in your tank.

Don’t confuse vermetid snails with other similar-looking organisms, such as worm tubes or other snail families. Worm tubes are dull inside and have only two shell layers, while vermetid shells are shiny inside and have three shell layers. Other snail families have more regular coiled shells and don’t produce mucous nets. Here are some examples of images of vermetid snails in different habitats and situations:

How to Remove Vermetid Snails

Once you have identified vermetid snails in your tank, you need to act fast and remove them before they cause more damage to your corals and other tank inhabitants. There are many methods of vermetid snail removal, but not all of them are equally effective or safe. Here are some of the pros and cons of various methods of vermetid snail removal:

Manual Removal

This is the most hands-on method since you’re actively getting rid of each snail yourself, but it is also the most tedious and time-consuming. You need to use gloves, tweezers, or coral cutters to carefully pull out or cut off each snail from its substrate, making sure not to damage your corals or other tank inhabitants. This method is best for small infestations or isolated areas.


Though this is another manual method, it requires much less effort. Sometimes referred to as the lancing method, this involves using a sharp object like a needle or a toothpick to puncture the shell of each snail, killing it instantly. You don’t need to remove the dead snails from their substrate, as they will eventually decompose or be eaten by scavengers. Depending on the size of your tank and your bio-filter, you may want to remove them to prevent raising your nitrates or phosphates. This method is best for hard-to-reach areas or large infestations.


This is quite a simple method that involves using super glue or epoxy to seal off the opening of each snail, preventing it from feeding. You don’t need to remove the glued snails from their substrate (unless they bother you), as they will eventually die and decompose or be eaten by scavengers. This method is best for small infestations or areas where puncturing is not possible.


This is a natural method that involves introducing fish, crabs, shrimp, or other organisms that can eat vermetid snails into your tank. Some examples of vermetid snail predators are pufferfish, triggerfish, wrasse, and bumblebee snails. However, not all predators will eat vermetid snails consistently or exclusively, and some predators may also harm your corals or other tank inhabitants. For example, many Yellow Coris Wrasse are known to eat vermetid snails, but just as often, you’ll get one that has little to no interest in them. You do need to choose your predators carefully and monitor their behavior and compatibility with your tank. This method is best for moderate infestations or as a supplement to other methods.

Chemical Treatments

This is a drastic method that involves using chemicals like hydrogen peroxide, sulfuric acid, vinegar, or bleach to kill vermetid snails outside of your tank. You will need to remove the infested rock and administer chemicals in a separate container like a bucket. These types of chemicals will kill not only the vermetid snails but also everything else, including coral and any beneficial bacteria living on the rock. In most cases, I’d recommend removing the coral and just getting a new rock. Sometimes though, there is some sentimentality to rock because of its shape or the way you’ve designed your rockscape, so I get the occasional need to clean and reuse a particular one.

Tank Breakdown

This is the most extreme method that involves taking apart your entire tank and cleaning or replacing everything. You need to remove all your rocks, corals, and other tank inhabitants and place them in a quarantine tank. You need to scrub, dip, or bleach your rocks to get rid of any vermetid snails or eggs. You need to replace your sand, water, and filter media to eliminate any traces of vermetid snails. You need to reassemble your tank and cycle it again before reintroducing your tank inhabitants. This method is very labor-intensive, extremely time-consuming, and stressful for you and your tank inhabitants. You need to use this method only if nothing else works and you have a severe infestation.

As you can see, there is no perfect method of vermetid snail removal. Each method has its advantages and disadvantages, and you need to weigh them carefully before choosing one. The best method for you depends on the size and severity of your infestation, the type and condition of your tank inhabitants, and your personal preference and budget. The most important thing is to act quickly and remove vermetid snails as soon as you notice them in your tank. The longer you wait, the harder it will be to get rid of them.

How to Prevent Vermetid Snails

Now that you know how to remove vermetid snails from your tank, you may be wondering how to prevent them from coming back. After all, prevention is better than cure, right? Well, the bad news is that there is no foolproof way to keep vermetid snails out of your tank forever. These snails are sneaky and resilient, and they can hitchhike on almost anything that you introduce into your tank. The good news is that there are some preventive measures that you can take to reduce the chances of vermetid snail introduction and infestation. Here are some of them:

Quarantine New Arrivals

The best way to avoid introducing pests such as vermetid snails is to quarantine everything that you add to your tank. This includes live rock, coral frags, fish, invertebrates, and even plants. Quarantining means keeping them in a separate tank for at least a month and observing them for any signs of disease or parasites. You can also inspect and clean them before adding them to your display tank. This way, you can catch any vermetid snails or eggs that may be hiding on them and prevent them from spreading to your main tank.

Regular Tank Maintenance

The last preventive measure that you can take is to perform regular tank maintenance. By this, I mean the basics, such as; water testing, water changes, filter cleaning, substrate vacuuming, and algae scraping. But also simply inspect your tank on a regular basis for any pests or other undesirables, like these vermetid worms. Keeping up on your maintenance can help keep your water quality high and your nutrient levels low, which discourages the growth and reproduction of vermetid snails. They also help you monitor and control vermetid snail populations by allowing you to spot and remove any snails that may have slipped through your quarantine.

By following any or all of these preventive measures, you can greatly reduce the risk of vermetid snail introduction and infestation in your tank. However, you should always be vigilant and check your tank regularly for any signs of these pests. If you see any vermetid snails or their mucous nets, don’t hesitate to remove them as soon as possible!


Well, there you have it, folks. Everything you need to know about vermetid snails and how to deal with them. These snails are nasty and destructive pests that can ruin your reef tank if you let them. But you don’t have to let them.

You can recognize them by their worm-like shells and their sticky mucous nets. You can remove them by using various methods, such as manual removal, puncture, glue, predators, chemical treatments, or tank breakdown. And you can prevent them by quarantining new arrivals and regular tank maintenance. By following these tips and tricks, you can keep your tank healthy and pest-free. And that’s what we all want, right? A beautiful and thriving reef tank that we can enjoy and be proud of.

So don’t let vermetid snails get you down. You have the power and the knowledge to fight them off. And I’m here to help you along the way. If you have any questions or comments about vermetid snails or anything else related to reef keeping, feel free to leave them below. I’d love to hear from you and share my experience and expertise. And if you liked this article, please share it with your fellow reefers and spread the word. Together, we can make the reef hobby better and more fun for everyone. Thanks for reading, and happy reefing!

Q: What are vermetid snails?

A: Vermetid snails are a family of marine gastropods that have irregular tubular shells that look like worms. They are usually found cemented to rocks or other surfaces or living in colonies. They are considered pests by many aquarists because they can harm corals by feeding on their mucus and blocking their polyps with their sticky webs.

Q: How do vermetid snails feed?

A: Vermetid snails feed by extending a long mucous thread from their shell opening and capturing plankton and organic matter from the water. They then retract the thread and consume the trapped food. This feeding method can interfere with the feeding and respiration of corals and other sessile organisms nearby.

Q: How do vermetid snails spawn?

A: Vermetid snails spawn by releasing eggs and sperm into the water column, where they fertilize and develop into planktonic larvae. The larvae then settle on suitable substrates and start building their shells. Vermetid snails can spawn multiple times a year and produce large numbers of offspring, making them difficult to control.

Q: Why are vermetid snails a problem?

A: Vermetid snails are a problem for reef aquariums because they can cause significant damage to corals and other invertebrates. Their mucous threads can irritate and smother coral polyps, reducing their growth and health. Their shells can also compete for space and light with corals and encrust over them.

Q: How to remove vermetid snails?

A: There are several methods that can be used to remove vermetid snails from an aquarium, depending on the severity of the infestation and the preference of the aquarist. Some of the most common methods are: crushing, gluing the tube shut, and occasionally adding a predatory wrasse.

Here are 5 FAQs about vermetid snails:

  • Manual removal: This involves physically removing each snail from the surface or breaking off their shells with tweezers or a knife. This method is effective but time-consuming and may damage the substrate or corals.
  • Puncture: This involves piercing the shell of each snail with a needle or a toothpick, causing them to die. This method is less invasive but may leave dead snails in the aquarium, which can decay and pollute the water.
  • Glue: This involves covering the shell opening of each snail with super glue or epoxy, preventing them from feeding and breathing. This method is simple but may not kill all the snails, as some may have multiple openings or escape before being glued.
  • Predators: This involves introducing natural predators of vermetid snails into the aquarium, such as wrasses, crabs, shrimps, or nudibranchs. This method is natural but may not be selective, as some predators may also eat beneficial organisms or become pests themselves.
  • Chemicals: This involves using chemicals that kill vermetid snails, such as hydrogen peroxide, vinegar, or potassium permanganate. This method is drastic but may be effective for severe infestations. However, it may also harm other organisms in the aquarium and alter the water chemistry.
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