Space Marine Crab (Tiwaripotamon caeruleum) Care Guide

We gave this crab the name “Space Marine Crab” since this is the first time they have entered the hobby and they don’t really have a common name, the exoskeleton coloration on many individuals really resembles Space Marine armor.

They are found around limestone mountains in Vietnam, where they are also sometimes collected by local people for food. This is a freshwater crab that needs access to both land and water, but the water portion is more important. The land area can be as simple as a few large rocks sticking above the water.

Because they molt underwater and come from limestone environments, we recommend keeping them in harder, higher-pH water. This is easy to recreate by using crushed coral or limestone in the water. Many experienced Asian keepers use limestone in their setups and have had good results. Avoid putting a lot of leaf litter, moss, or other acidic organic material directly into the water, since it can lower the pH over time.

Temperature should not go below 68°F (20°C) or above 82°F (28°C). Avoid direct sunlight. These crabs can become stressed very quickly when exposed to it, and any exposure may cause serious problems.

For food, they seem to enjoy catching insects on land, so live crickets and roaches are good options. They will also eat fish pellets, and we recommend offering them from time to time to give them a more varied and balanced diet.

There are currently two main ways people keep them, and since this species is still very new to the hobby, we don’t have enough experience yet to say that one method is definitely better.

The first is a mostly terrestrial setup with a separate water container deep enough for the crab to fully submerge and molt. For the land area, maintaining a higher pH should also be a priority. We recommend using mostly large rocks with a thin layer of substrate, such as crushed coral/limestone, or a mix of the two. If using this setup, keep the humidity in the enclosure as high as possible.

The second method, and the one that currently seems to have more documented success, is a mostly aquatic setup. This can be very simple: a layer of crushed coral with some limestone, water deep enough for the crab to completely submerge, and a few large rocks extending above the surface so the crab can come onto land whenever it wants.

Since this species is still very new to the hobby, please do not treat this as an absolute care guide. We expect to learn much more about their care as more people gain experience with them, and we also hope to stay in communication with our customers and learn from their long-term experiences with this species.

Terrestrial Setup

Aquatic Setup