GEOSESARMA (Vampire Crabs)
Table of Contents
Introduction
Physical Description
How Many Species are There??
Habitat and Distribution
Behavior and Diet
Species Highlights
Care in Captivity
Breeding
Conservation Status
Frequently Asked Questions (FAQs)
Introduction
Geosesarma crabs, often called Vampire Crabs because of their bright yellow eyes and intense colouration. They are small, semi-terrestrial freshwater crabs found primarily in Indonesia, Malaysia, Thailand, and the Philippines. Unlike many crab species that require brackish water, Geosesarma crabs only live in freshwater environments, which is why they have become extremely popular in the pet trade.
These crabs are mostly nocturnal, extremely shy, and very skittish, which is something a lot of people buying them as pets aren’t expecting.
Physical Description
Vampire Crabs typically measure about 2–3 cm (0.8–1.2 inches) in carapace width. They are known for:
Vibrant Colours: Bright purples, reds, oranges, yellows, and even blues, depending on the species. At the time of writing there are more than 75 different species known to science, though most aren’t yet officially described.
Distinctive Eyes: Often glowing red or orange, resembling vampire eyes.
Compact Size: Perfect for nano tanks and terrariums.
Strong Claws: Used for defense and feeding.
Their colouration and patterns are often unique to each species, making identification easier for hobbyists.
How Many Species are There?
At the time of writing, there are more than 75 different species of Geosesarma Vampire crab currently known to science. Most of which have yet to be officially described. You can find a full list of species with pictures here.
Habitat and Distribution
Geosesarma crabs are native to:
Southeast Asia: Including Indonesia (especially Java and Sumatra), Malaysia, Thailand, and the Philippines.
Environment: They inhabit freshwater streams, rivers, and forest floors with high humidity and plenty of leaf litter and rocks.
Unlike fully aquatic crabs, these species spend significant time out of water but still need access to freshwater to stay hydrated. When sitting up a tank to keep them in at home, it should be 80% land and 20% water.
Behaviour and Diet
Vampire Crabs are:
Nocturnal: Most active during night hours.
Social: Can live in groups, but territorial disputes may occur.
Omnivorous: Eat a varied diet including algae, decaying plants, small insects, and commercial crab food.
They are excellent scavengers, helping maintain the tank ecosystem clean.
Care in Captivity
For keeping Vampire Crabs healthy and happy:
Tank Size: Minimum 10 gallons for a small group.
Water: Freshwater with pH 6.5–7.5, temperature 22–26°C (72–79°F).
Substrate: Moist soil, sand, or coconut fiber to mimic forest floor.
Hiding Spots: Plenty of rocks, plants, and driftwood.
Diet: Commercial crab food supplemented with vegetables, algae, and protein sources.
Humidity: Maintain high humidity levels with misting or covered tanks.
Regular tank cleaning and water changes are essential.
Breeding
Breeding Geosesarma crabs in captivity is challenging but rewarding:
Mating usually occurs in moist terrestrial environments.
Females carry eggs under their abdomen.
Juveniles hatch as miniature crabs — no planktonic larval stage.
Provide hiding spots and soft substrate for juveniles.
Breeding success improves with stable water conditions and varied diet.
Conservation Status
Some Geosesarma species face habitat loss due to deforestation and pollution. Captive breeding programs help reduce wild collection pressures, but sustainable practices are vital to protect natural populations.
Frequently Asked Questions (FAQs)
Q: Are Vampire Crabs aggressive?
A: They can be territorial but generally peaceful if given enough space.
Q: Can Vampire Crabs live with fish?
A: Small, non-aggressive fish can cohabitate but monitor for signs of stress.
Q: How long do they live?
A: Typically 2–3 years in captivity with proper care.
Q: Do they need both water and land?
A: Yes, they are semi-terrestrial and require access to both.