The vampire crab has recently found its way into the aquarium hobby and has enjoyed some popularity. This crab has much to recommend it. Unlike many freshwater crabs that can barely survive without brackish water, this species can actually thrive with only freshwater. Additionally, they breed in captivity without a fragile larval state, making it easier for them to reproduce in a home aquarium.
You should keep your vampire crabs in groups of two to six individuals. Unlike some freshwater crabs, they generally do not pick on each other, so a little colony will get along just fine. A colony of this size can comfortably live together in a standard 10-gallon aquarium. However, the aquarium needs to have some special accommodations for the crab; a regular fish tank setup will not suit them.
Decorations and Setup
Vampire crabs need access to both land and water. Technically, this would make the setup a vivarium or paludarium instead of an aquarium. The crabs spend at least half of their time on dry ground. Also, use a sandy substrate, since these crustaceans like to burrow. Keep their water clean, filtered and heated to around 70 degrees Fahrenheit. Make sure both their land and water includes hiding places. Java moss makes a great decoration, since it can adapt to both the land and water, and the crabs may browse on it.
Vampire crabs can share their enclosure with some other invertebrates. For example, they will not harm larger snails. Additionally, they are reported to get along with most ornamental aquarium shrimp. However, fish make a dicey proposition. While the crabs may not harm fish, most fish cannot thrive in the tiny water volume of a small vivarium. The small size of the vivarium would likely exclude fish.
To keep your vampire crabs thriving, you will need to accommodate their diet. Vampire crabs are omnivores and will eat most foods offered. You can use fish flakes or crustacean food -- available at pet shops -- as their main staple. However, they treat small crickets as a treat. To ensure the crickets are pesticide-free, you can purchase them at pet shops, either alive or dead.