Thousands of little blue creatures are washing up on California beaches

One of thousands of creatures known as “by-the-wind sailors” that have been washing ashore on Southern California beaches in April.

Allen J. Schaben/Los Angeles Times via Getty Images

The Velella velella, a name so nice you gotta say it twice.

Who are they? The tiny disc-like critters are colonial hydrozoans, classified under the phylum of cnidaria, and their eponymous genus of Velella (not a Game of Thrones reference).

• Formally titled the Velella velella (say that five times fast) you may know them as by-the-wind sailors.   
• The sailors are a couple of inches long, and vary in striking shades of cobalt and baby blue while they’re alive.
• They have a similar build to jellyfish, but have a small sail protruding from their bell, explaining the name and their migratory patterns.

What’s the big deal? California beachgoers have reported seeing thousands of the Velella velella along the shoreline recently, though they typically live far offshore.

• And their sails can explain it! They rely completely on the wind and ocean currents to move around, and when the conditions are just right, like with recent storms, they can get pushed up onto shore. 
• They also lose that beautiful blue hue once they leave the embrace of ocean waters and die onshore, typically becoming grayish or transparent. And with no exoskeleton to keep their shape propped up, they shrivel up to resemble plastic. 

• Their top predators include gloriously hued sea slugs and a special breed of predatory snail.  

Want more on oceans? Listen to the Consider This episode on why melting ice in Antarctica is a big problem for coastal Texas.