Xanthid Crabs are often colourful and usually poisonous to eat, if they are big enough. They are a more conventional looking type of crab.
You can often spot one of them on coral reef based dives with Chaloklum Diving.

Coral Crab; Cymo andreossyi

This small, furry crab is usually found in the branches of Acropora table corals.

9 Photos

Other Xanthid Crabs, Xanthidae

These normal looking crabs are reasonably common in our area.

8 Photos