A visitor at the Cape Lookout National Seashore in North Carolina who came across a “weird” white, prickly object along the ocean banks has left park staff “stumped” as to what the bizarre thing might be.

A close-up photo shows dozens of white, bone-like structures in the shape of wishbones attached to what appears to be one long, grey object. Facebook users rolled out a number of ideas ranging from pufferfish spines to eel vertebras in the comments section. According to Molly Zaleski, a marine biologist based in Alaska, she thinks the strange object could be “some sort of porcupinefish’s spines.”

“I would think they’re clumped like that on dried skin of a dead fish,” Zaleski explained, citing a 2015 blog post by marine author Susan Scott. In it, Scott writes that similar white spikes in all stages of decay are so common on Baja’s desert beaches that she often wears shoes to protect her feet.

“From the first picture, I almost feel like I can see a fish eye on the bottom left of the dried area with a few stripes leading to it, similar to what you might see on a striped burrfish, but it's hard to draw conclusions without it in hand,” said Zaleski.

Porcupine and pufferfish get their name from the unique ability to inflate their bodies with water and stick out sharp spines in an attempt to ward off would-be predators, according to the Atlantic City Aquarium.

“When a predator attacks the porcupine fish, it inflates its body by inhaling air or water which makes it grow larger in size and makes its spine protrude from its body. Other fish cannot grip or bite the inflated body of the pufferfish and hence, it is protected from its enemy,” wrote the aquarium. Other comments mention the structure could be that of a striped burrfish, which Zaleski confirms is found off of the Atlantic coast and a member of the porcupinefish family.

The park service adds another theory to the pot: a plumed worm case that was created using the white, bony structures as part of its case.

“It could be possible that the plumed worm decorated itself with the bones of a porcupinefish, but I’m leaning towards just the bones on the dried remains of the fish itself,” said Zaleski. “I’m sure the park service ecologists will be able to tell if that inner connection is a tube or a dried fish body with a little dissection detection.”

Update: Following the publication of this article, Cape Lookout National Seashore provided the below information. 

"Fisheries scientists at the Virginia Institute of Marine Science, as well as many others, have identified our weird object as the remains of a striped burrfish (Chilomycterus shoepfi). The bony structures are the fish's defensive spines. Apparently, these remains can even show up in the fossil record and are known to paleontologists. So no tube worm case decorations this time."