Chances are, if you’re reading this you’ve come across a vermetid snail in your time as an aquarist. These wormy fiends are one of the most dreaded pests in the saltwater community, and for good reason! Before you make an effort to remove these unassuming freeloaders, let’s understand what they are and where they may be coming from.
When adding new live rock and coral, it’s inevitable that you’re going to come across a hitchhiker or two. Hitchhikers are creatures that hitch a ride onto live rock or pieces of coral and remain unseen when added to your aquarium. While adding biodiversity into your ecosystem is beneficial, we have to remember that like all ecosystems, there are creatures that are more beneficial than others.
Understanding Vermetid Snails
Vermetid snails come from the Vermetidae family, but are commonly referred to as ‘worm snails’. Their nickname comes from their unusual shell that resembles a worm and their tendency to stay in crevices of rocks. The Vermetidae family houses over 160 species across temperate parts of the ocean where there's a steady food source of detritus and plankton. Wondering why you haven’t heard of such a populated species? That may be because they’re at their biggest at 4cm and extremely elusive, but don’t worry! They have a calling card.
These hide and seek pros are difficult to identify because of their calcified tubes and neutral coloring. Juvenile vermetid snails resemble tiny spiral shelled snails for a brief moment before finding a hard surface to call home. Adult vermetid snails look very similar to tubeworms, giving them their nickname ‘worm snail’. They’re unique in their ability to break themselves down to their shell, as it's part of their feeding structure, in case of competition for space or damage. The actual snail lives in the small hole where they attach to coral or other structures.
Call Sign
Odds are if you’re reading this, you know about mucus nets. It’s about as gross as it sounds. Because vermetid snails stay in one spot for the entirety of their life, they send out long nets of mucus to catch detritus and plankton (and even gametes and spermatophores) in the current before reeling it in. A tell tale sign of your aquarium inhabiting vermetid snails is long, stringy mucus nets covering your rocks and coral (think Spider-Man or silly string).
While these snails are relatively peaceful in nature, their tube shell stops coral from growing and nets of mucus smother inches of territory at a time, suffocating coral and stealing their food source. On top of all of this, they reproduce quickly and because of their inability to move, cover lots of space.
Mucus Begone!
So, you’re probably desperate for some good news. Luckily for you, we’ve got some: they don’t move, they leave tracks, and they’ve got predators. If your vermetid snails cast out nets, follow them to their source. Their calcified shell allows you to pluck them off with bone cutters or a pick, just remember to take the entire object they’re latched onto before attempting so they don’t fall back in and cut from the latching point. If you want a less invasive option, use reef safe superglue and seal off that mucus entrance to cut off their food source. If these options aren’t paying off, emerald crabs, yellow coris wrasses, coral crabs, and bumblebee snails love to snack on them. If you’re at a loss and need a last-resort option, you may need to turn to hydrochloric acid. It is vital to do extensive research on this before executing for both you and your aquarium’s health.
Prevention
Like everything else in the aquarium hobby, patience is key. The best way to stop these pests from infiltrating your underwater paradise is to quarantine any new rock or coral and pick them off prematurely. Already smothered in mucus nets? Give us a call and we’ll give you a lift!