This beautiful mollusk has a gentle neon glow.
Donald Quintana photographed this otherworldly sea creature in a tide pool in Cayucos, California. It's called an opalescent nudibranch, a type of mullusk that sheds its shell after its larval stage.
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Update: If you want to see videos of this beautiful creature, here they are: 4 videos of the beautifully strange opalescent nudibranch (aka colorful alien-looking sea slug)