Red apple crab

Care at a glance

Overview

This small, color-changing crab is semi-terrestrial, so it needs a paludarium with both land and shallow water rather than a full aquarium. A group lives together peacefully when there is enough room, humidity, and hiding space, so provide plenty of cork bark, wood, and leaf litter for cover, especially at molting time when a soft-shelled crab is vulnerable. Keep the land area planted and damp, with easy exits from the water so they can climb out to bask. Feed an omnivore mix of blanched vegetables, dried foods, and occasional protein such as bloodworm. A setup of around 40 liters or more houses a small group.

In the wild

The red apple crab comes from damp coastal forests in Indonesia and the Philippines, living on the moist forest floor at the edge of fresh water rather than submerged in it. Recreate that with a land-and-water paludarium: a humid, planted land section over hard, alkaline water. Keep it warm at 24 to 28 C with a pH of 7.5 to 8.2, and cover the tank, as these crabs climb and will find any gap.

Good to know

Metasesarma aubryi is a sesarmid crab, family Sesarmidae, only a few centimeters across the shell. It is known for changing color with mood and molt cycle, shifting from deep apple red through orange to near black. Breeding is hard in captivity because the larvae need brackish or salt water to develop, so raising young from a home paludarium is rarely achieved.

Did you know

The same crab can look bright scarlet in the morning and slate gray by evening, which is why it is also sold as the chameleon crab. The color tracks its mood and molt cycle, not its species or its health.

Common questions

Related species

• 

  Red vampire crab

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• Blue-leg vampire crab

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• Orange vampire crab

  Geosesarma tiomanicum

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• 

  Purple vampire crab

  Geosesarma dennerle

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  1 in (2.5 cm)10 gal (38 L)75–82°F (24–28°C)
• Pom Pom Crab

  Ptychognathus barbatus

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  1.6 in (4 cm)5 gal (20 L)72–82°F (22–28°C)
• White claw Towuti crab

  Syntripsa flavichela

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  3.1 in (8 cm)20 gal (75 L)79–86°F (26–30°C)