Temperature Range:  68 – 82 F.
Humidity: 75% +
Diet:   Omnivore
Habitat:   Freshwater
Life Span:   1 - 2 years
Species:  Geosesarma sp. borneo
Size:  up to 1 ½”

Orange Arm Crab History
Orange arm crabs originate from one of the largest islands in Indonesia, Java Island, just south of Borneo.  They are freshwater crabs, and can typically be found in swamps or marshes. In an aquarium setting, they need equal parts land and water.  The bodies and carapace of the orange arm crab are dark brown to black. Only its scissors are orange, which of course is how it gets its name. Orange arm crabs have black eyes. Males have hair on the last third of their claws.

Orange Arm Crab Care
Orange arm crabs are easy to care for, and it is not difficult to get them to reproduce in captivity. Their aquarium should be layered, with a large area of freshwater as well as plenty of terrain for them also. They will frequently sit above the water and dangle their legs in the water. The water temperature should be in the range from 68 to 82F, and the tank environment should be humid.  You should change their water once or twice a week so that it will remain clean and fresh. They will do well with other orange arm crabs in the same tank, but you shouldn’t put them with aggressive fish or larger crabs that might eat them.

Orange Arm Crab Diet
Orange arm crabs are omnivores. They eat meat, such as brine shrimp, mosquito larvae, Cyclops, and pieces of earth worms. They will also eat fresh vegetables and apples, pears, bananas, etc. You can feed orange arm crabs a wide range of packaged foods, such as algae flakes, shrimp pellets, and fish flakes. You can also give orange arm crabs extra calcium in the form of eggshells, cuttlebone, or cuttlefish. They will eat their own discarded exoskeletons for calcium as well.

Orange Arm crab Reproduction
Orange arm crabs reproduce in fresh water. The female carries several eggs under her apron, although in captivity the exact number varies. When the eggs hatch, the emerging offspring appear as miniature adults rather than larvae. The larvae will have all dark coloring; their claws will not appear orange until they mature. Care should be taken to protect the offspring from predators while they are very small and vulnerable.

Orange Arm crab Behavior
Orange arm crabs are sociable, so they don’t like to be alone, and they will do well with other orange arm crabs.  However, they are small and somewhat vulnerable to predators. They will spend some of their time in their water, but more often they will sit above the water with only their legs resting in it. It is important that they have room to do this.

Special Notes
Orange arm crabs relatively easy to keep, provided you keep their water clean and keep them away from predators. They are not the most active species of crab, but they are attractive and make a good aquarium crab because of the relative ease of maintaining them.