Sea cherubs are washing up on Oregon beaches. Here's what we know about the 'specialized sea slugs'

PORTLAND, Ore. (KOIN) – Small, translucent creatures -- known as sea cherubs -- are washing up along Oregon beaches, and more sightings are occurring in 2025 than usual, according to Seaside Aquarium.

In a January 18 Facebook post, Seaside Aquarium announced they have been seeing and receiving reports of the “highly specialized sea slugs” washing up on Oregon beaches.

Sea cherubs spend their lives in the open ocean with “a pair of swing-like paddles which are used for swimming and are able to propel themselves quickly," Seaside Aquarium said. “While they may not look like it, they are voracious hunters and can take down prey three times their size.”

On Tuesday, Seaside Aquarium told KOIN 6 News they started getting reports of the sea slugs washing ashore around January 14 and are still seeing them on the tide line up and down the coast – including sightings in Seaside, Cannon Beach and Arcadia State Park.

“Sea cherubs are very delicate creatures and usually die quite quickly once on the beach," a spokesperson for the aquarium explained. “While they can swim, they cannot swim against the ocean's currents, so you can put them back in the water, but they are going to wash back in.”

The spokesperson said aquarium employees were able to collect a few sea cherubs that washed ashore and were still alive, noting they brought them back to the aquarium so they could educate visitors about them.

“They are not harmful to humans but like all things that wash up on the beach it is best to keep your dogs from eating them,” Seaside Aquarium said.

Sea cherub sightings are typical this time of year, the spokesperson said. However, “this year there seems to be more than usual, but we are also seeing one of their main food sources, sea butterflies, washing in in larger numbers as well.”

The spokesperson noted beachgoers do not need to report sea cherub sightings as organizations may not be studying the animals, adding, “We just happen to be invertebrate nerds and love to share what we find.”