Watch Ghostly 'Sea Angels' Swim Through the Depths

Some are called sea angels, others sea butterflies. Whatever you call them, the pteropods are really, really cool.

You might not know it to look at them, but the pteropod is a type of snail. Where other snails have a single, solid foot for scooting along the sea floor, the pteropod’s feet have split into wings, allowing the eyeless, translucent snail to to “fly” underwater.

They may look lovely, but their eating habits are … less so. Some pteropods are active hunters who will eat other pteropods when they find them. But others go fishing: They deploy a big, slimy net of mucus, then drift through the water, collecting the disgusting detritus known as marine snow.

And as they eat, so are they eaten. Pteropods are really important to the food chain. Some scientists call pteropods the “potato chips of the sea,” because just about everyone eats them.

Stephanie Bush (script writer and narrator of this video) is a postdoctoral fellow at the Monterey Bay Aquarium Research Institute. You can read more about her pteropod research here.

Header image via YouTube // MBARI