Often difficult to find in the tank, these crabs can climb almost anything and have been known to leave the tank! (Click photo for source)

Kingdom: Animalia

Common Name:
Red-Clawed Crab

Scientific Name: Sesarma bidens

Taxonomy:
Kingdom: Animalia
Phylum: Arthropoda
Class:
Malacostraca
Order:
Decapoda
Family:
Grapsidae
Genus:
Sesarma
Species:
bidens

Natural Range
This crab is originally from Thailand, Hong Kong, and Singapore. They mostly live in freshwater tanks.

Interesting Facts
They are mostly harmless, though they are aggressive towards their own kind. They will rip claws and legs off until dead. They are best kept with middle or top fish to avoid any pinching, though none usually occur.

Links
Find out more here:

 

The Red-Clawed Crab and CLHS

The freshwater tank in the science lab has two red-clawed crabs. They will hide for days at a time, then reappear in most unusual places—even on top of the tank!