TankBud

Purple vampire crab

Geosesarma dennerle

Also known as Vampire crab

FreshwaterCrab

Purple vampire crab (Geosesarma dennerle)
AverageWalrus · CC BY-SA 4.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
7.5–8.0
Adult size
1 in
2.5 cm
Minimum tank
10 gal
38 L
Temperament
Mostly peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Difficulty
Medium
Breeding
Medium
Rarity
Very common
Family
Sesarmidae
Origin
Central Java, Indonesia

Overview

Keep them as a species setup, several females per male, in a paludarium of 38 liters or larger with mostly land. They are bottom dwellers that spend their time on the substrate and climbing bark and plants, and they are aggressive and territorial. They are predatory toward other species and cannibalistic toward their own young, so do not mix them with fish, shrimp, or other crabs. Hold the water warm at 24 to 28 C, hard, and alkaline at pH 7.5 to 8. Feed a mix of dried foods, blanched vegetables, and protein like bloodworms or small bits of fish, and offer cuttlebone or another calcium source for molting.

In the wild

Purple vampire crabs come from Central Java, Indonesia, where they live along stream banks and damp forest floor more than in the water itself. They are semi-terrestrial, so set them up in a paludarium that is roughly 80 percent land with a shallow water area, not a normal aquarium. Give them fine sand for burrowing, dense plants, and bark hides, plus high humidity and a tight lid to hold it in. The water stays warm at 24 to 28 C and should be hard and alkaline, with a pH of 7.5 to 8. Plan for a footprint of at least 38 liters.

Good to know

This is Geosesarma dennerle, a small land crab in the family Sesarmidae. The body reaches about 2.5 cm, with a legspan of 4 to 5 cm. Unusually for a crab, it breeds in fresh water and releases fully formed young, skipping the ocean-going larval stage that most marine and brackish crabs depend on. Most stock in the trade is wild collected.

Did you know

Most crabs have to release their larvae into salt water, where the babies drift as plankton before settling. Vampire crabs skip all of that. Females hold a small clutch of eggs and release tiny, fully formed crabs straight into fresh water, which is why a colony can keep breeding in a tank with no ocean access at all.

Common questions

What size tank does a Purple vampire crab need?

A Purple vampire crab needs at least 10 gal (38 L). It spends most of its time in the bottom.

What temperature and pH does a Purple vampire crab need?

A Purple vampire crab is comfortable at 75–82°F (24–28°C) with a pH of 7.5–8.0.

How big does a Purple vampire crab get?

An adult Purple vampire crab reaches about 1 in (2.5 cm).

Related species