Red-spotted Guard Crab

Image: Mark Rosenstein
Trapezia tigrina

Don't mess with the Red-spotted Guard Crab. You might catch something.

This small, Indo-Pacific species is well named; it's a crab, it has red spots and it's constantly on guard duty. And what does it guard, you ask? It guards its home, its food, its friend. In short... its coral.

Red-spotted Guard Crabs spend their lives among the complicated branches and passageways of cauliflower and staghorn corals. They feed on the sweet, sweet nectar exuded from the very walls of their castle. By which I mean they eat mucus produced by the coral polyps. That's one way of dealing with rising damp.

Image: Steve Childs
MY house

The corals mostly like their mucus to stay where it is, but having it scratched away and eaten by a small, unassuming crab is a small price to pay for what the plucky crustacean does in return.

Having settled in their illustrious, candy-coloured fortress, Guard Crabs aren't about to watch it get eaten by some languid itinerant! Coral-eating fiends like the Crown of Thorns Starfish are viciously attacked, pinched to high-heaven by those mighty pincers. Or at least pinched until they go next door. Same difference, right?

And if that doesn't work then I THINK I'm right in saying that the chicken pox will.