Rainbow land crab

Care at a glance

Overview

Keep one crab on its own, since they are solitary and aggressive, and two adults will fight to the death in the same enclosure. They live on the bottom and along the land, burrowing into the moist sand and coming out to forage. Give them at least 90 liters, water from 24 to 29 C, and a pH of 7 to 8 on the slightly brackish side. Fit a tight, heavy lid because they are strong escape artists that will climb out of any gap. Feed a mixed diet of vegetables, fruit, and protein like fish or shrimp, and keep them with no other animals, since they will catch and eat small fish.

In the wild

Rainbow land crabs come from brackish river deltas along the west coast of Africa, where they spend most of their time on land near the water rather than fully submerged. They are semi-terrestrial, so they need a paludarium, not a fish tank, with roughly half land and half water. Build a deep, moist sand bed they can burrow into and keep the water side slightly brackish to suit them best. Aim for at least 90 liters of floor space, water from 24 to 29 C, and a pH between 7 and 8.

Good to know

This is a true land crab in the family Gecarcinidae, reaching about 12 cm across the shell as an adult. It cannot be bred at home because the larvae need full saltwater to develop, so nearly all of them in the trade are wild-caught. They can live several years when kept well. There is no captive-bred line to choose from.

Did you know

Despite living mostly on land, this crab still breathes through gills and has to keep them damp, which is why it never strays far from water. The bright orange, purple, and cream colors fade and brighten depending on its molt cycle and condition, so a freshly molted crab looks at its boldest.