This past summer, a San Diego, California, resident named Anya Stajner was taking an evening stroll down the beach in La Jolla when she spotted something purple in the sand. As she looked more closely, she realized it was a little snail.
If anyone else had spotted the purple snail, they might have admired it for a second and moved on. But Stajner isn’t your average beach stroller — she happens to be a PhD candidate at the Scripps Institution of Oceanography.
Stajner quickly identified the animal as a Janthina, a snail typically found only in warm tropical waters. Stajner was shocked — she’d never seen a Janthina in California before.
“I’m … overjoyed that my knowledge about marine zooplankton led me to immediately recognize these specimens as Janthina and to understand how rare it would be to stumble across them on the beach in San Diego,” Stajner wrote on Instagram.
While most marine snails live on the sea floor, Janthina actually live in the open ocean. They use a special mucus bubble raft to help them float upside down on the water’s surface, where they feed on invertebrates like Portuguese man o’ war. Even their bright coloring helps them thrive in their unique habitat.
“It’s believed that their violet shells have their vibrant color because it protects the Janthina from the harsh UV rays it’s exposed to at the surface,” Stajner wrote on Instagram.
Stajner transported a few of the snails she’d found on the beach back to a lab at Scripps Institution of Oceanography to have a closer look at them. There, she confirmed with her fellow oceanographers that there hadn’t been a documented Janthina spotting in San Diego for ten years.
So what were these Janthina doing so far from home? No one knows for sure, but it’s most likely related to changing ocean temperatures. On the day Stajner found the Janthina, she’d noticed that the water had felt unusually hot.
“[T]heir stranding along the Southern California coast is often linked to warmer offshore waters flowing toward the shore,” Scripps Institution of Oceanography wrote on Instagram.
Only time will tell whether Stajner’s Janthina sighting was a fluke or a sign of their habitat range shifting. Either way, Stajner is glad to have encountered the fascinating animals.
“I feel so lucky to have stumbled upon these striking ocean creatures who live such a unique lifestyle,” Stajner wrote.
