Red armed giant crab (Discoplax magna)

Common Name: Red Armed Giant Crab / Orange-legged Land Crab
Scientific Name: Discoplax magna 

Adult Size: Up to 10.5cm carapace width
Native Range: Eastern Indian Ocean

Enclosure: Terrestrial vivarium/paludarium with lots of floor space; deep, diggable substrate plus multiple tight hides
Heating: Tropical terrestrial species; avoid chilling

Humidity: Provide damp/moist substrate zones with strong ventilation (not stagnant)

Diet: Mixed plant matter (leaf litter/greens/veg) plus animal proteins in rotation

Water: Freshwater dish large enough for dipping; keep clean and easy to access

ABOUT THIS SPECIES

Discoplax magna is a large, fully terrestrial gecarcinid land crab best known in the hobby for its chunky build and bold contrast dark to brownish carapace with orange to red chelae in many adults.

In the wild it’s associated with well-forested karst habitats and can be found surprisingly far inland, sometimes a kilometre or more from the sea, as long as the ground stays damp. It spends daylight hours tucked away, then emerges to forage, with a strong tendency to dig burrows beside trees and rocks, especially where there’s moist soil and rotting vegetation to work into.

In captivity that usually translates to a crab that values cover and substrate depth above “open display” space, and will settle best when it can disappear into tight retreats and excavate its own hideouts.