|Image: Pablo Bou|
The Yellow Umbrella Slug is a gastropod from the Mediterranean Sea and nearby parts of the Atlantic Ocean. It usually reaches about 4 cm (1.6 in) long.
Their weird umbrella-shell is reminiscent of the kind of thing limpets use to brave the crashing waves as they cling fast to rocks on the shore. Umbrella Slugs aren't what you might call "true limpets", though; they're just one of a whole host of snails who took to wearing their shell like one of those cool, Asian hats.
|Image: Géry Parent|
As it turns out, we needn't worry for the Yellow Umbrella Slug. They have a few tricks up their sleeve. And under their hat.
For one, it may be surprising to know that their vibrant yellow colour is great camouflage!
Yellow Umbrella Slugs are almost always found on one particular - extremely yellow - sponge called Aplysina aerophoba. They eat it...
|Image: Philippe Guillaume|
And where do you think the slug's yellow colour came from in the first place? It's from a pigment they "borrow" from the sponge.
But that's not all they get from their food. They also incorporate alkaloids which help deter predators! Granted the sponge was using it to deter its own predators before it got preyed upon, but still...
Forget umbrellas. Real security is a sponge.