Profile of the 711 Crab (Carpilus maculatus)

Crab (Carpilius maculatus) from National Museum, Prague, Czech Republic
Crab (Carpilius maculatus) from National Museum, Prague, Czech Republic. Karelj/Wikimedia Commons/CC0

Scientific Name

Carpilus maculatus (Linneaus, 1758)

Other Common Names

None Known


The body is an oval shape and of an orangish-light rust color. It has seven large dark reddish-maroon colored spots on its back. These spots can appear to look more of a dark brownish color at times. Its shell is extremely thick and heavy, but smooth and lacks spines.


Hawai'i and the Indo-Pacific area.


Like most crabs, the 7-11 is a scavenger and will eat just about anything! This crab has been observed in nature carrying sea urchins and cowrie shells, suggesting a possible food preference. It mostly comes out at night to feed, hiding during daylight hours.

Watch out, because this crab has VERY strong pinchers!! Once it clamps on to something, it is difficult to try and get it to let go or forcibly open the pincers.

The 7-11 Crab's great strength and strong armor make it quite a destructive animal in an aquarium. Not only does it act like a bulldozer moving rock scapes and corals around in an aquarium, but it will attack and eat other crustaceans and invertebrates, and if given the chance, grasp on to sleeping fish.

Care Rating

We suggest a Four Star Care Rating Level for this crab. As far as caring for this crab, that's the easy part. It adapts quickly to aquarium life. However, because of its destructive nature, it is not a crab we would recommend to keep in an aquarium, even if it does look cute and appealing when its small!