Arrow Crab (Stenorhynchus seticornis)

Max Size: 10 inches
Diet: Carnivore
Temperament: Semi-Aggressive
Reef Compatible: With Caution. May eat soft polyp corals.
Minimum Tank Size: 30 gallon

The Arrow Crab, also referred to as the Spider Crab, is characterized by its elongated legs and arrow-shaped body and head. Its size varies with some individuals reaching up to 10 inches, while females may be much smaller. Different species of Arrow Crabs are found in various regions, including the Caribbean, Indo-Pacific, eastern Africa, and California. These crabs usually reside in parts of the reef that are associated with small caves or crevices.

Arrow Crabs are long-lived and robust invertebrates that can be housed in a reef aquarium. However, they have been known to attack Banded Coral Shrimp and small, slow-moving fish. Like all crabs, they are opportunistic feeders and will search for food by picking at mushrooms or polyps if insufficient food is present. Nonetheless, Arrow Crabs can be beneficial in the aquarium by eating smaller Bristle Worms that are often considered pests. Breeding Arrow Crabs in captivity is generally not successful, and their larvae are free-swimming and hatch after about two weeks. Arrow Crabs can be fed almost all types of meaty, flake, and tablet foods.