Interesting Inverts - Mandarin Vampire Crabs

Mandarin Vampire Crabs (Geosesarma notophorum) are an intruiging species to keep in the home paludarium. They are semi to mostly terrestrial crabs native to the stream side forests of Indonesia. The males of the species will be larger and have exaggerated claws when compared to the females; when small these differences can be hard to quantify. In the wild, they exist on filamentous algae, forest floor detritus, and decomposing plants etc. They are a very small crab reaching a max size of only 2.5 inches or so but average closer to 2 inches at adulthood.

Because of their diminutive size, these crabs do not need a huge amount of space, though they do have other fairly specific requirements. As a communal species, they should be kept at least in pairs, and better yet is small groups. Keep these groups to their species as while they get along well with other Vampires, they will likely be aggressive with other crabs.

Displays should be carefully planned; while they will spend most of their time on land, they do need some freshwater as they will submerge themselves frequently, and in addition, need it to molt. Ensure the transition from water to land is climbable for the crabs or they can get stuck in the water and drown. They also like quite a bit of cover, and are notorious climbers so we recommend adding scape for them to climb, but also a lid to keep them from escaping (which they will do.) In larger displays they seem to do well with live plants, and do little to them. They will clean up around the plants and pull dead leaves etc. In smaller displays this clean up seems to be too impactful for some plants, which suffer as a result of the intense scrutiny of the crab. Ideally the paludarium should be humid and warm 75 to 82 degrees and over 75% humidity. A small display for a couple specimens could be 5-10 gallons, 40 gallon breeder tanks make great displays for larger paludariums because of their long footprint.

Feeding is very easy as they are used to looking at just about anything for food. They are omnivorous scavengers (and like most opportunistic scavengers, will hunt as well). As such, they do an excellent job cleaning up the tank, but in addition, like all “cleaners”, they need supplemental food. Feed them a mix of high quality crab / freshwater fish foods, as well as fresh (or not quite so fresh) vegetables, insects, worms etc. While they will eat old fruit, it seems to decompose to fast in the paludarium, making a bigger mess than it is worth (plus fruit flies are a pain to get rid of).

With a little planning Vampire Crabs make an excellent addition to the right display. They are easy to care for, are very colorful and have interesting behaviors to watch. A small group of them could easily be the central feature of a paludarium, or a pair could be an added interest to a display with fish.