It seems ironic that a creature that spends its day licking the mud can look so elegant. But, that is the case for the humble brown mud snail. This plain little gastropod blends in perfectly with its mucky surroundings so well that it often looks more like a series of little dots on the mud than anything living.

While periwinkles, their smaller and neater little cousins that are found on rocks and on seaweed, are typically shy and take some coaxing to emerge from their shells, mud snails readily wiggle their gooey bodies right out of their shells. That’s when their beauty shines – and they perform according to their other common name – Spanish dancer. Their bodies come so far out of their shells that it seems impossible they could still be attached. But somehow they are able to fit their long, serpentine bodies inside shells that are no more than half an inch long.

The body of a mud snail looks gooey and soft, but it is actually very strong. This is what allows it to twist and turn itself to wriggle out of its shell. It also helps the snail to carry its shell across the mud while traveling on its giant “foot”. Because snails get their food by slithering along on top of their food, they have evolved to have their stomachs right inside their feet. Snails are gastropods, which literally means “stomach foot”. They are omnivores and eat tiny bits of anything plant or animal found on the surface of the mud. In another display of their unexpected elegance, as they feed, they leave a series of mucus-y trails along the surface of the mud that interweave into a pattern that looks like lace.

The other part of a mud snail’s body that is super-specialized is its siphon. This is the long noodle-like organ that comes out of a little slot in its shell and helps it to find food. It pumps water in through the siphon and over an odd chemo-sensitive organ called an osphradium that can detect prey. Osphra means “smell” in Greek. This is helpful since snails don’t have eyes. They do have an eyespot on one pair of their antennae that can detect the difference between light and dark. They use another pair of antennae to find their way around and detect scent.

The other amazing thing a mud snail’s foot helps it do is to dig down into the mud. This is important for escaping from predators. Even though they are well camouflaged, mud snails are easy snacks for birds and small fish. Their shells help to protect them to a certain degree, but getting down beneath the surface is the best strategy. For savvy human hunters, however, they are easy to find if you look for the tiny holes they make in the mud as reach up to the surface with their siphons to filter out water.

Mud snails are critical parts of the mud-flat food chain that help to recycle little tidbits of plants and animals into useful nutrients. They lay their eggs on another one of the critical components in this ecosystem – eelgrass. I recently came across a frond of eelgrass that was covered in tiny little translucent dots and did some research to find out that these are the eggs of mud snails. It seems fitting that they would start out life attached to the same plant life that will later decompose into the

tiny bits of matter they will eat as adults. And that, as adults, the mud snails will return nutrients to the water that the eelgrass will need to grow each spring.

These little gastropods are just one of the many creatures that are often overlooked on the mudflats because they appear mucky and plain. But, they are full of bizarre and beautiful adaptations that help them to survive and contribute to this important coastal ecosystem.