Zoanthids are quite popular in the hobby and for very good reasons. They have a variety of beautiful colors, relatively easy to care for, and look like little flowers. However, sometimes we notice our little gardens starting to wilt away. Trying to figure out what could be wrong, you check your water parameters. You then find out nothing is out of the ordinary. Next, you double check to make sure your fish and invertebrates in the tank are reef safe. So, what could be happening to your zoanthids? Well, there is one little pest who could be munching on your zoanthids known as the Sundial snail.

The Sundial snail, formally known as Heliacus variegatus, is a smaller snail that has distinctive black and white markings on its shell. Sometimes, these snails can have an orange tint to their shell as well. Furthermore, these snails have a rattlesnake-like tail coming out of their shell. To top things off, this snail stands out even more because of how it carries its shell. This snail’s shell stands perpendicular to the surface it’s on. In other words, imagine taking a nickel and having it stand on its side.

Even though these snails aren’t very discrete at all in appearance, why can’t we find them? The answer to that lies in their behavior. Sundial snails are nocturnal snails, so they only come out at night to feed. They can be seen every now and then during the day, but they try to avoid doing that because of potential predators. During the day, these snails will hide under the polyps of your zoanthids.

In the event you find these snails in your tank, there are a variety of ways to remove them. You can always remove them manually by plucking them out of your system. Another method would be to introduce some predators of snails like hermit crabs or pufferfish but do some research to make sure your new predator will get along with the coral and other fish in your tank. Also, you can dip your zoanthids to cull the population in your tank. The best option would be a combination of all these methods to get rid of these pests!