Noticing some jelly-like, blue blobs on San Diego beaches lately? Those are none other than Velella velella, also known as "by-the-wind sailors" or "little sails."
First things first — better to not touch them! Their stings are not strong enough for human skin, but these jellyfish-like creatures are more closely related to the dangerous Portuguese man o' war than to the ethereal moon jellies — so if you do stick a finger out, you might easily touch the wrong creature.
Velella velellas are gelatinous-looking blue discs with clear "sail-like" tops, which they use to move themselves across the surface of the ocean.
Long piles of Velella velella could be seen on Del Mar Dog Beach, in Imperial Beach and across the border on the beaches in Tijuana and Rosarito on Tuesday.
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While it may seem like a lot, current numbers are not outside of what has been documented in the past, said Linsey Sala, Senior Museum Scientist and Collections Manager of the Pelagic Invertebrate Collection at University of California, San Diego.
Why are we seeing them on our shores lately?
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During sunny seasons like spring and summer, the Velella velellas head to the water's surface because there's more food there, said Sala.
These animals have no other way of moving than by wind and tides. They have two main food sources: eating tiny beings that live near the water's surface and the sun. Yes, you read that right.
They also possess symbionts that can photosynthesize — similar to hard corals, which are using sunlight to create energy. By being at the surface and using their sails to move, they are able to obtain both sources of energy, Sala said.
However, they are also at the whim of the tides and winds. The tides will push them out to shore, where they can accumulate in long piles or "strandings," as Sala calls them. This is where you will probably see them in San Diego.
In April of 2023, Pacific Beach visitors also reported noticing the unusual-looking things in the sand.
Once they end up on our shores, they may never return to where they came from.
"So once they are up on the high tide line, then that's usually where they'll remain, unless of course the next tide comes in and takes them back out. But usually a day in the sun up on the sand will probably be their end," Sala said.
By the time they're drying out in the sun, they might not die right away, but they will likely have begun degrading, Sala said. Even so, it's safer not to touch or let your pets touch them.
"It usually isn't a problem like other jellies in terms of packing a painful sting for us. Of course, we do have a few other jellies here in Southern California that have a purplish color to them that could sting," Sala said.
"Even things like Portuguese man o' war, once they're up on the shoreline, they can still pack a mean sting. And if you don't know how to tell them apart, then maybe you just want to look at them, take a picture with them, and be on your way," Sala said.
Velella velella do have stinging cells like many other true jellies and other gelatinous cnidarians (the family jellyfish are in), but their stings are targeting really small crustaceans, larvae and other such tasty creatures (for them).
The "sails" on these creatures make them unique in the animal world. Another animal that uses wind to move is a snail called "Janthina Janthina," Sala said.
"It's called the bubble snail because it blows a bubble raft and floats along the surface of the ocean on that bubble raft and lives in that pleustonic layer [the top layer of the ocean]. And 'pleuston' actually comes from the Greek root meaning 'to float," Sala said.
Last year, NBC 7 spoke with Ben Frable, a collections manager at the Scripps Institution of Oceanography, who said the Velella velellas are commonly seen off the coast of California and sometimes up in Oregon and Washington state.
