Low tide at Bunche Beach is always a treasure hunt, but this particular morning felt especially magical. It was a chilly early December day, and we were out with a group of adults attending our Florida Master Naturalist program. We were tracing the delicate track of a juvenile horseshoe crab across a shallow tide pool, hoping for a glimpse of the little explorer who left it behind. As we gently scooped through the soft sand, something unexpected surfaced — a tiny cone no more than a few inches long.

“At first glance, I thought we had uncovered a tusk shell. But when I looked closer, something didn’t add up.” Shared Shannon Rivard, Sanibel Sea School Director. “The cone wasn’t smooth at all. It was textured — almost pebbly. Then it hit me: the entire structure was made of individual grains of sand, each one carefully glued into place.”

We had found a trumpet worm, also known as an ice cream cone worm! “I could hardly contain my excitement. I’ve never seen a live one before,” said Rivard. “Any day I meet a new creature is a very good day, and discoveries like this remind me that the coast always has surprises tucked just below the surface.”

No matter how much we explore, there’s always something new waiting.

What is a Trumpet Worm?

The cone we uncovered wasn’t a shell at all — it was the tube home of a trumpet worm (likely Pectinaria gouldii), a small but fascinating resident of the Gulf’s intertidal and shallow zones.

Trumpet worms build their tubes grain by grain, using a natural protein “glue” they secrete to cement each piece of sand in place. The result is a fragile, one-grain-thick structure that can grow up to about 7.5 cm (3 inches) long. Narrow at one end and wider at the other, the tubes are sometimes called sand castles — a fitting name for such delicate architecture.

These worms settle into fine-grained sediment, orienting themselves vertically with the wide end (the head end) down in the sand. Only the narrow end sticks slightly above the surface. They use sturdy golden bristles called setae to dig, then rely on small tentacles to sort edible particles from the sediment. Trumpet worms are detritivores, which means they feed on tiny bits of organic material mixed into the sand. As they process sediment, they play a small but important role in recycling nutrients in coastal ecosystems.

Finding this little “ice cream cone” in a tide pool was a beautiful reminder that the shoreline is full of surprises. Whether it’s a well-hidden worm or an unexpected track in the sand, the coast always rewards curiosity.

Contributing Author: Shannon Rivard

Sources:

https://txmarspecies.tamug.edu/otherdetails.cfm?scinameID=trumpet%20worm

https://www.inaturalist.org/taxa/194009-Pectinariidae