Written 2020, Last updated 03/10/2024

Natural habitat and enclosure design- 

Vampire Crabs are native to Southeast Asia, including many of the islands of Indonesia. In the wild, many members of the Geosesarma genus will be found alongside tropical forest streams. Here they seek shelter beneath dense foliage, leaf litter, rocks, and down burrows, before emerging to feed as night draws in. Whilst these crabs are unusual in their terrestrial nature, they are still heavily reliant upon water for survival- it is in water they will moult, feed, and reproduce. Providing the perfect balance of these areas is vital in a captive environment. 

For your crabs to thrive, a paludarium setup should be used. This is a type of enclosure which uses the fundamental principles of terrarium and aquarium design to create a naturalistic ‘shoreline’ habitat. In this case, our ‘terrarium’ section will be inspired by the thick undergrowth of the Indonesian forests, whilst the ‘aquarium’ section will replicate the tropical freshwater streams of the area. 

A terrarium- such as those manufactured by Exo Terra- or a repurposed aquarium are great ways to start your build. Just ensure that the base of the terrarium will allow enough depth for your water area, at least 10cm before substrate. A tight-fitting lid is also a vital consideration, as these crabs are known to be daring escape artists and are capable of climbing almost any vertical surface! Care should also be taken to ensure that any holes for wires, or large air vents, are appropriately escape-proofed, whilst still allowing adequate air flow. 

A group of 4 crabs (1 male: 3 females) can be housed in a tank as small as 60x30x30cm, however larger groups, and breeding populations, will require larger accommodation. My own paludarium is 100x50x50cm and now houses 3 adults and multiple clutches of their offspring. 

As mentioned, Vampire Crabs are secretive, and spend much of the day concealed, whether beneath objects in their environment, down burrows, or amongst dense foliage. To ensure these natural behaviours can be carried out in captivity, there are some essential habitat requirements: 

• Deep substrate- a deep layer of substrate in the terrestrial section will enable crabs to burrow. It will also help to keep humidity levels at the desired level and support the growth of live plants. Various tropical forest substrates are available commercially; however, keepers often opt to create there own mixes, utilising materials such as coco fibre, sand, orchid bark, and carbon. To ensure that the land area does not become waterlogged, use a drainage layer (such as clay balls) in the tank. You’ll also want to keep this area separate from the water using either a divider or by creating a false bottom. As the land area approaches the water, you may wish to add stone to the substrate to replicate the natural features of Indonesian stream banks. 

• Decor items- items such as rocks, branches and cork bark will add clutter to the tank, making the inhabitants feel secure and dividing territories. Smaller decor items, such as seed pods, leaf litter, and other botanicals, can also be used as refuges. These are ideal for younger crabs, but also break down over time, nourishing the substrate. This helps to maintain the natural cycle of nutrients in a bioactive enclosure. 

• Live plants- foliage plants, such as ferns and creeping fig, are well-suited to the Vampire Crab’s natural habitat, and are native to Southeast Asia. Foliage not only livens the space, making it aesthetically pleasing for the keeper, but also helps to maintain the health of the tank and its residents. Live plants will be used as a food source and a place to seek shelter by the crabs, whilst increasing humidity levels in the tank. 

Between 20% and 40% of the enclosure’s surface area should be made up of water. Although much of their time is spent on land, these crabs are still reliant on water bodies for survival. Whilst a small bowl or tub of water can be used to satisfy this requirement, I would always recommend a full paludarium style setup, as discussed above. 

As with the terrestrial portion of the enclosure, there are certain essential features: 

• Substrate- to create a natural environment, substrate is vital. Any aquarium sand or gravel could be used, but I would suggest the use of fine sand. This is representative of the species’ natural habitat and will allow easy movement and natural foraging behaviours. Crabs may find it difficult to move across gravel or a bare-bottom tank. 

• Access- whilst Vampire Crabs are capable climbers, it is important to consider access points into and out of the water. This is particularly important for tanks housing juvenile crabs, which could otherwise drown. In my own tank I use several natural features to fulfil this purpose. Pebbles, slate pieces, and coarse stone chippings are arranged along the bank of the ‘stream’ in step-like formations, whilst various plants, branches, and logs overhang the water’s edge to assist the crabs in climbing out. 

• Parameters- the water must also be heated and filtered to ensure the crabs remain healthy. The specification of this equipment will be heavily dependent upon the size of your tank and the volume of the water area. This is covered further in the next section. 

Environmental conditions and water chemistry- 

Vampire Crabs hail from the tropical regions of Southeast Asia, very close to the equator. As a result, they are used to warmer temperatures than those here in the UK! Average daytime temperatures in Java, one of the warmest Indonesian islands, are 32 degrees Celsius, with nighttime lows of a toasty 24 degrees Celsius.  

I have found that heating the water area to 26 degrees Celsius with a small submersible heater helps to maintain an appropriate air temperature of 24 degrees Celsius, provided the temperature of the room does not dip too low. If your temperatures remain too low, a thermostatically controlled heat mat should be used to help raise the ambient air temperature- this should be situated on one side of the tank. Overhead heating equipment is likely to dry out the tank too quickly, leading to difficulty maintaining the high humidity levels these creatures need to thrive.

Lighting should be used to create a regular day-night cycle. As the species resides near the equator, day length fluctuates only very slightly throughout the entire year. Usually there is a difference of less than an hour between the length of the area’s longest and shortest days, with an average day length of around 12 hours. This can be controlled using an automated plug-in wall timer. 

Various lighting methods are available, from daylight bulbs to LEDS and UVB. Full-spectrum LED lighting will aid plant growth and create effective day-night cycles. Some products can now even simulate the sunrise and sunset for a more natural lighting cycle. UVB lighting is another main option, typically associated with reptile care. Whilst studies are still exploring the use of UVB lighting for invertebrates, it is likely that it will still benefit health and behaviour, as it does with many other species. On the other hand, as these crabs are most active at night, they may not benefit from UV lighting in the same way as diurnal or basking animals. 

Humidity is another important parameter. To maintain appropriate humidity levels, regular misting will be required. Humidity levels can be increased by more regular misting, the use of an automated misting system, live plants, or by covering part of the mesh roof (if using a conventional terrarium). Care should be taken to ensure that in increasing humidity, ventilation is not restricted, as this may cause unhealthy stagnation. In the wild, humidity levels remain high year-round, with an average of 87%. This increases with the heavier rainfall in February. Keepers should monitor the humidity levels in their enclosure using a digital hydrometer. 

As mentioned in the previous section, the aquatic portion of the setup must be filtered to maintain the appropriate water chemistry values. Live aquatic plants could also be used to help clean the water. The ideal water chemistry values are: 

• pH: 7.5 to 8.0 

• Hardness: 0-10KH, 4-16GH 

• Salinity: 0ppm (freshwater) 

• Ammonia: 0ppm 

• Nitrite: 0ppm 

• Nitrate: 20ppm 

• Temperature: 26 degrees Celsius 

These values can be tested regularly using a simple dip stick test, following the manufacturer's instructions. Water changes should be carried out regularly to maintain good water quality. The use of RO (reverse osmosis) or dechlorinated water is also recommended for the health of your crabs. 

Diet and captive feeding- 

Wild crabs are omnivorous, feeding off both plant and animal matter. They will eat almost anything they can scavenge or catch! This includes terrestrial inverts, shrimp, small fish, vegetation, algae and much more. Some species are more adept at capturing live prey than others, but all will appreciate a varied diet. 

Especially for breeding crabs, protein and calcium are vitally important. As a result, I feed a wide variety of feed items to provide a close alternative to their wild diet: 

• Small crickets  

• Mealworms 

• Isopods 

• Bloodworm (live or frozen) 

• Brine shrimp   

• Copepods  

• Dried fish 

• Dried shrimp 

• Other small feeder inverts, for land or water  

• High protein fish flakes/crushed pellets  

• High calcium vegetables such as kale, spinach, and broccoli  

• Old moults (crabs moult their exoskeletons to grow, and will often eat parts of this- I usually remove it from the water to prevent it causing bad water quality, but place it on the land to be consumed) 

• Leaf litter and debris  

• Algae (this often grows naturally in the water area as part of a healthy ecosystem)  

• Other veg such as cucumber  

• Commercially available crab food 

As the crabs will scavenge for extended periods throughout the night using their claws and mouthparts, I like to ensure that food is constantly available and scattered right across the tank. This will promote natural foraging behaviours and reduce conflict. In a live planted or bioactive setup, Vampire Crabs can almost become self-sufficient, feeding from live plants, old botanicals, and the bioactive clean-up crew (isopods, springtails, etc.). 

Wild behaviour and enrichment- 

Throughout this guide we’ve explored many of the natural behaviours of this terrestrial crustacean. They spend much of their time on land, and emerge at night to feed, breed and moult, when the forest is most safe. Provided the enclosure is setup in a natural and enriching way, your Vampire Crabs will thrive, showing off their natural behaviour. 

Varying the feed types and scattering feeds- including live invertebrates- will also help to keep the species active and using their natural instincts. 

One thing we have yet to touch on is their social requirements. Whilst Vampire Crabs can be territorial (especially males) they do benefit from the company of their own kind and should be kept in groups. It is important to house an appropriate sex ratio and avoid housing too many males in a small enclosure, as they can kill each other. The typical recommendation is to keep 1 male to every 3 females. It is also vital that different species are housed separately as conflict can often occur between them- despite this many pet shops house various types together. 

Health and disease prevention- 

Vampire Crabs are relatively hardy, especially those born in captivity. For this reason, there are rarely too many health concerns to deal with, and with good husbandry you are unlikely to encounter any issues. 

Keeping the habitat clean will ensure that disease risk is reduced. This is important in the aquatic area, which should be cleaned, including a water change, regularly. This will reduce the likelihood of bacterial infection, which may be caused by poor water quality. Food waste should be removed from the land and water areas, although this can be left on the land in bioactive habitats as the clean-up crew will help to control waste levels. 

Wild caught individuals can sometimes arrive worse for wear, carrying disease or parasites, and missing one or more of their limbs. For this reason, captive bred crabs should be purchased wherever possible. 

Other sources- 

Ali’s Menagerie was delighted to have an article featured in the February 2024 issue of Exotics Keeper magazine. The piece, titled ‘Breeding the Bloodthirsty: Vampire Crab care and breeding’ covers all aspects of their care, and includes further information on how to successfully breed these enchanting crustaceans. 

Looking to buy Vampire Crabs? 

Ali’s Menagerie breeds limited numbers of Vampire Crabs in our own collection. UK residents are welcome to contact us for more information, and to check our current availability.