Geosesarma hagen is a species of small land-living crabs which is found on Java, Indonesia. The crabs are dark brown with the chelae and parts of the carapace being bright orange on the adults.
Geosesarma hagen adult and young
It is popular in the aquarium trade, where it is sometimes called “Geosesarma red devil” or “Geosesarma sp ‘rot'” (“rot” means red in German). All species of Geosesarma crabs are often called “vampire crabs” in the aquarium trade.
The species is named after The Rolf C. Hagen Group of Companies, who supported work by Christian Lukhaup and Christoph D. Schubart, two of the authors of the describing article. source