Once fully grown though they are primarily carnivorous, hunting nocturnally and preying on a variety of organisms.

M. novaezelandieae hunts by using its powerful chelae to catch, kill, crush and access its prey, then feeds using its mouthparts.

[3] New Zealand Maori have historically eaten crabs as part of their kai moana (food from the ocean) diet.

Crabs were an easy resource to gather as they are often found in coastal shallows, making them easily accessible sea food.

M. novaezelandieae is most likely among the many species of crabs the Maori ate, as it grows to a size large enough to be considered for eating, as well as being found throughout New Zealand.