Lybia tessellata

Identification: trapezoid carapace about 2.5 cm wide, divided by dark lines into differently coloured plates like stained glass; walking legs with dark bands and white speckles, much larger than the slender claws. The body is drab (brown, beige or pale orange) and the colourful anemones are what catch the eye.

In the wild it lives in shallow tropical waters from the Red Sea and East Africa to Indonesia and New Guinea, at 1 to 20 m, on sand and gravel bottoms where it is well camouflaged and on live corals it clings to. The anemones are usually Bunodeopsis or Triactis producta. Facing a predator, it brandishes its anemones, whose stinging cells defend it.

Reproduction: females carry red eggs under the abdomen. In a related Red Sea species, Lybia leptochelis, experiments showed that a crab deprived of one anemone tears the remaining one in two, both regenerating into complete anemones, and that a crab without anemones steals one from another crab (Schnytzer et al., 2017).

Status: the species has not been evaluated by the IUCN and is not listed by CITES; it is rarely collected for the aquarium trade.