‘Trash’ on South Carolina beach turns out to be egg casings for cannibal snails

One of South Carolina’s popular coastal towns says pieces of “plastic” littering its beaches are actually egg casings for a large, predatory snail.

The casings look remarkably like the top of a plastic bottle, complete with decoratively fluting.

“If you’ve been on our beach lately, you will have seen a lot of these strange looking objects,” the Town of Kiawah Island, about 30 miles south of Charleston, posted on Facebook.

“At first glance, one might think they are pieces of plastic or trash. They are actually a moon snail’s egg casing or ‘sand collar.’”

The casings are not considered dangerous but could hurt if stepped on with a bare foot, experts say.

However, moon snails are “voracious predators” known to grab hapless clams, drag them beneath the sand and devour them with “seven rows of teeth,” according to the Slater Museum of Natural History.

“They are cannibals — which means they eat each other too,” Gulf of Maine Inc. reports. “Apparently, they follow each other down into the sandy mud and then sometimes cannot control themselves.”

The species lives by day “just below the surface of the sand” and pops up only at night — like vampires — to feed, according to a report by Friends of Island Beach State Park.

Commenters on the town’s Facebook post said they had seen the casings in the past week and believed they were garbage washed from the ocean.

“I thought it was some kind of litter coming from ships,” Gaye Stathis wrote.

This story was originally published January 21, 2020 at 2:49 PM.