Scaphella Junonia

By Claire Ferguson

Junonia shell at the beach (Amanda Collett).

The junonia shell is considered by many shell enthusiasts to be the holy grail of shelling. Some shellers spend a lifetime searching for the rare, coveted gem, flocking to the beaches of Sanibel and Ten Thousand Islands in Florida hoping to discover this infamous beauty. But what about the creature that once lived inside of it? Residing in the deep waters of the Gulf Coast, information about the animal inside the shell can be just as elusive as the shell itself, although there have been some recent discoveries.

Junonia shell finds (Amanda Collett).

The species is called Scaphella junonia, a large sea snail named after the Roman goddess, Juno, a powerful and fierce warrior, majestic in size and beauty. The striking spindle-shaped shells are cream-colored with rows of contrasting dark-brown dots that decorate the exterior. The shell swirls itself into a point with an aperture about three-quarters of the length. Adult shells typically grow to about three or four inches, although the largest ever recorded junonia shell measured over six inches and was found in 1972 in Mexico. So far, two other Junonia subspecies have been found. The Scaphella junonia butleri found off the Yucatán Peninsula (Mexico, Belize, and Guatemala) is slightly lighter in color with faded spots. And the Scaphella junonia johnstoneae found in Alabama’s waters appears almost striped due to the spots being darker and closer together. Additional subspecies could be waiting to be discovered.

Junonia shells and fragments as found on the beach (Meredith Blain). 

The mollusks are gastropods, which means they move with a singular, muscled “foot,” able to flap, swim, climb, and burrow into the sand, which is how they spend most of their time. Junonias live miles offshore and deep underwater, from 90 to 425 feet below the surface, which makes the shells difficult to find. It takes powerful wave action to wash the empty shells up to shore, and if they do withstand the rough, tumbling waters they are often damaged or found in pieces. “I know many avid shellers who have shelled 50 years or more and have never even seen a piece of a junonia shell,” says collector Amanda Collett. “Shellers who do find whole perfect junonias are most definitely the lucky ones.” Shellers recommend searching the beach after a big storm or hurricane for a better chance of finding a junonia shell, as heavy winds tend to stir up deeper ocean material.

Live Scaphella junonia snails (Rebecca Mensch, Bailey-Matthews National Shell Museum).

Because so little is known about the Scaphella junonia, marine biologist Rebecca Mensch from The Bailey-Matthews National Shell Museum decided to pursue further research on the species. In 2018, she joined Dr. Gregory Herbert from University of South Florida, Tampa, and his research crew on an expedition to the Gulf of Mexico. Using a dredge box, they were able to find three live male junonia snails, which Dr. Herbert agreed to loan to the museum for further study. The snails are currently on display in the Living Gallery at the museum, offering a glimpse of the stunning, yellow-and-black-spotted body of the snail. At the front of the soft “foot,” you can make out a distinct face with tentacles sticking out like a mustache. Although cute, don’t let these charming little critters fool you—they are powerful, deadly, self-sufficient predators.

Researchers at the museum observed that the junonias prefer to dine on the lettered olive, a slightly smaller gastropod mollusk. What’s interesting about the junonia is its uncommon feeding style. Captured on video, the junonia strikes the lettered olive from the side with a retracting proboscis that has a mouth on the end, causing the olive to recoil abruptly. Initially, it appears the lettered olive is dead, but it is likely immobilized by a sort of muscle relaxer. Mensch observed one lettered olive being stunned and then moving around again 15 minutes later, before eventually being eaten by the junonia overnight. A cloudy milky white substance was released upon attack indicating a possible salivary venom, but further research is needed to be certain. Photographs also captured a green film around the junonia engulfing the lettered olive with its foot, perhaps excreted from one of the animals.

While much has been discovered about this remarkable species, many mysteries remain. The scientists at Bailey-Matthews are hoping to answer more questions about the reproduction, growth, and lifespan of the junonia. “When and if you find a special shell like the junonia, you will never forget the experience of that magical moment,” says Amanda.

View the live junonia snails at the Bailey-Matthews National Shell Museum or watch them on YouTube at youtu.be/I9A5UAL5G8A. Read about and see photos of the junonia feeding on the lettered olive: Leal, José H, and Rebecca A Mensch. “Swift Strike by the Gastropod Scaphella Junonia on Its Gastropod Prey Americoliva Sayana.” Bulletin of Marine Science 95.1 27–28.

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This article appeared in the Beachcombing Magazine March/April 2022 issue.