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Blue Dragon Sea Slug

Blue Dragon Sea Slug: The Tiny Dragon That Eats Jellyfish

Glaucus atlanticus

Tiny, gorgeous and armed with stolen venom

It looks like a Pokémon and fits on your fingertip. The blue dragon is a sea slug that floats upside down on the open ocean, eats venomous Portuguese man o’ wars and keeps their stingers for itself. Pretty. Do not touch.

Blue Dragon vs. you

Your height cm170 cm

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Why is this animal unusual?

The blue dragon eats animals most predators avoid, and then recycles their weapons. It moves the man o’ war’s stinging cells, unfired, into the tips of its own finger-like limbs – and packs them so tightly that its sting can hurt more than the original.

Why does it look like that?

It floats belly-up, held at the surface by an air bubble it swallows. The blue side faces the sky and blends with the sea. The silvery side faces down and blends with the bright surface. Camouflage in both directions.

Strangest biological feature

Stolen weapons. The stingers it collects aren’t its own – yet they still fire when something touches it.

Why is it strange?

Every blue dragon is both male and female. After two of them mate, both lay eggs. They have also been known to eat each other.

Interesting behavioral facts

It can’t really swim – it drifts wherever wind and currents push it. That’s why whole “blue fleets” sometimes wash up on beaches together.

Blue Dragon Sea Slug

Know someone who needs to see this?

Send them the Blue Dragon. They'll thank you. Probably.