Watch as creature uses ruse to spray its larvae on unsuspecting fish in West Virginia

If a fish could turn itself inside out, the result would resemble a creature recently recorded on a stream bed in West Virginia.

The video, shared Aug. 4 on Facebook, shows what seems to be a glob of internal organs flapping in the current — including something like a brain.

Somewhere under all that flapping is a type of mollusk known as a plain pocketbook mussel, and it was “exhibiting a special behavior,” the West Virginia Division of Natural Resources said.

“This female is using her mantle as a ‘lure’ to attract a fish host. Note how much it resembles a minnow!” the division wrote.

“A predatory fish will eventually come along and fall for the mussel’s ruse, biting the lure prompting the mussel to release larval mussels called glochidia. The larvae will harmlessly attach to the fish until they transform into juvenile mussels and drop off to live in a new area.”

This elaborate display is necessary because the mussels don’t “swim or crawl, so hitching a ride on fish is the only way for them to spread throughout the watershed,” the division said.

Once the the mussel’s larvae latch onto a host, the fish’s tissue grows over them and they “transform into microscopic juveniles” in a matter of days or weeks, the U.S. Fish and Wildlife Service reports. “If by chance they settle into suitable habitat, a new mussel bed is created,” the service says.

Plain pocketbook mussels grow to a hefty seven inches and they are typically found in the “mud, sand and gravel” of lakes and streams, the service says.

West Virginia posted the video with a warning: While the mussels don’t sting or bite, they should be avoided at such moments.

“If you’re lucky enough to find a mussel displaying her lure, look but don’t touch!” the state wrote. “If something other than a fish disturbs her, she could have to wait more than a year to successfully reproduce.”

This story was originally published August 9, 2021 at 12:05 PM with the headline "Watch as creature uses ruse to spray its larvae on unsuspecting fish in West Virginia."