It's not just hordes of anchovies attacking the California coastline this summer, as a small, jellyfish-like creature with a cool blue hue has been washing up by the millions along shores up and down the state's coast since the middle of July.
The beach-crashing creature's full name is Velella velella (not a typo; it's the only species in its genus), sometimes referred to as "by-the-wind sailors," because they live on the surface of the water and are at the mercy of the winds for all of their travel plans.
As befits their nickname, velella have a kind of sail affixed to their tops, which is what allows them their out-of-control seafaring. They have few predators, although some sea slugs and water-bound snails will eat them.
It's not unprecedented for the creatures -- just a couple of inches long -- to be swept ashore in mass die-offs, but it's a bit late in the summer season for the mass strandings to occur. The reason for the tardy appearance remains a mystery.
The vellella isn't specific to California coastal waters but is happy in the warmer parts of oceans the world over. Despite this ubiquity, scientists still don't know a whole lot about their lives.