San Diego, California – Beachgoers along La Jolla Shores are witnessing a vivid and unexpected arrival: violet sea snails, small and gleaming like polished gemstones, have made a rare appearance along the Southern California coastline. These dazzling marine drifters, known scientifically as Janthina janthina, are almost never seen this close to land. Their sudden presence has sparked awe, curiosity, and scientific intrigue in equal measure.
Typically found far offshore in tropical and subtropical waters, Janthina are pelagic snails that spend their lives floating at the ocean’s surface. Each snail secretes its own buoyant raft made of air bubbles encased in chitin—a structure that keeps it aloft and allows it to drift with the currents. Unlike the slow-crawling mollusks familiar to tidepool explorers, these snails are wanderers of the open sea, tethered not to rocks or reefs but to their delicate, self-made flotation devices.
Their shells, only about the size of marbles, shimmer in hues of deep violet and lavender, making them a stunning contrast against the muted tones of sand and surf. But the color isn’t just a striking visual feature. It serves as a key part of the snail’s survival. The darker upper side of the shell shields the animal from predators above, blending with the shadowed ocean below, while the paler underside helps it evade detection from the fish swimming beneath. The purple pigmentation also provides protection from the sun’s ultraviolet rays—a necessary adaptation for a life spent at the ocean’s sunlit surface…