Species Snapshot
- Species Name: Geosesarma sp.
- Common Names: Vampire crab
- Size: Up to 2 inches
- Lifespan: Up to 2 years
- Native Distribution: Southeast Asia
With their vibrant coloration and social behavior, vampire crabs (Geosesarma sp.) make fascinating pets. Despite their intimidating name, vampire crabs are not dangerous. They’re relatively low-maintenance pets as long as you have the right setup.
If you’re looking for a new challenge, consider building a vampire crab habitat. Below you’ll learn the basics about these beautiful crustaceans and how to care for them.
Anatomy and Appearance
Vampire crabs are small, semi-terrestrial crabs that can be found throughout Southeast Asia as well as the western Pacific and eastern Indian Ocean. The genus includes more than 50 recognized species, though only a few have become readily available to hobbyists.
The two most popular vampire crab species are:
- Bi-Color Vampire Crab (Geosesarma dennerle)
- Red Devil Vampire Crab (Geosesarma hagen)
Most vampire crabs reach a maximum size of around 2 inches, including their leg span. Like other crabs, they have ten legs including two large pincers. While larger crabs can do a lot of damage with their powerful claws, vampire crabs have relatively weak claws. They’re comparatively small and don’t open wide enough to make them dangerous to humans.
Vampire crab coloration varies across species and selectively bred color morphs are rising in popularity. These crabs typically exhibit a dark-colored body with lighter coloring on the legs and claws. Vampire crabs are often reddish-brown but can also be found in vibrant shades of purple, red, and orange. Most species have bright yellow eyes protruding from the top of the head.
Like other crabs, vampire crabs are sexually dimorphic—there are visible anatomical differences between males and females. Male vampire crabs have larger claws and their abdomens are more prominent than a female’s.
Ideal Tank Setup
As semi-terrestrial crustaceans, vampire crabs require access to both land and water. The ideal proportion is about 80% land to 20% water, and high humidity is a must.
Because they’re small, vampire crabs don’t require large enclosures. They do, however, need their tank to be decorated properly to enable them to utilize all the space available—this includes vertical space to climb. A minimum tank size of 5 gallons is recommended for a group of three vampire crabs, but larger tanks are usually better.
A vampire crab tank should provide the following:
- A soft substrate that can hold enough moisture to maintain high levels of humidity—sphagnum moss and coconut coir works well for the land portion of the tank.
- A wide variety of plants as hiding places for the crabs as well as branches they can climb. Both immersed and submersed plants are recommended.
- A consistent humidity level of 75% or higher—you can accomplish this by misting the tank daily or by installing a humidifier.
- In the water section, the temperature should be 71°F -82°F with a pH level between 7.5 and 8.0. To keep the water clean, you’ll need to install a filter or replace the water regularly.
It’s important to keep a lid on your vampire crab tank. Not only will it help maintain the optimal level of humidity, but it will prevent your crabs from escaping. They’re very good climbers!
Diet and Feeding
With a name like “vampire crab,” you might expect these crustaceans to drain their prey of blood. In truth, the origins of the name are unclear. Some theories suggest the name is a reference to the crabs’ nocturnal nature or inspired by their glowing yellow eyes. Others suggest it’s simply a catchy name.
The vampire crab’s diet is not significantly different from other crustaceans. They are omnivores, so they consume a wide variety of foods including insects, decaying plant matter, and other detritus.
In captivity, vampire crabs will eat most commercial foods, but variety is important. Offer your crabs a staple diet of commercial crab pellets, shrimp pellets, and blanched vegetables. They may also eat bloodworms, brine shrimp, live or frozen foods, fish flakes, and algae wafers. Make sure they have a good source of calcium in their diet to help maintain their exoskeletons.
Temperament and Tank Mates
Vampire crabs are nocturnal, so they will be most active at night. It’s important to provide hiding places where they can rest during the day, including soft substrate they can burrow into. Having hiding places available is also important if you plan to keep more than a few crabs together. Males tend to be territorial, so it’s wise to keep a ratio of one male per two females.
Generally speaking, vampire crabs are best kept in a species-only tank. Keeping different species together is likely to result in fights for territory and females. Different vampire crab species may also interbreed which can result in color dilution.
It may be possible to keep vampire crabs with shrimp or snails to help keep the water section of the enclosure clean. Vampire crabs will prey on small snails, however, and may prey on the shrimp as well. This could be a benefit for controlling populations, however, so it’s up to you to decide whether you’re willing to accept occasional losses of other tank inhabitants.
Vampire Crab Molting
Like shrimp and other crustaceans, vampire crabs molt throughout their lives. This is the process through which they shed their rigid exoskeleton to make room for new growth. Vampire crabs molt frequently during the first six months of life but will slow to about one molt per month in adulthood.
Because the crab’s body will be extremely vulnerable after a molt until the new exoskeleton hardens, it’s very important to provide hiding places for your crabs. This is another reason to exercise caution when keeping other inhabitants in your vampire crab tank.
Other Interesting Facts
- Vampire crabs are relatively easy to breed in captivity when kept in the proper conditions. Due to their sexual dimorphism, it’s not difficult to distinguish between males and females.
- Having the right substrate is important for breeding vampire crabs—the females lay their eggs in the substrate to be fertilized by the males. The substrate will help protect the eggs until they hatch.
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