Hairy Hermit Crab

Geographical Origin and Habitat: Widely distributed in the tropical Indo-Pacific, from the Red Sea and East Africa to Hawaii and Polynesia. Inhabits shallow outer reef slopes and sandy lagoons.

Taxonomy: Member of the family Diogenidae. A large hermit crab species reaching up to 8-10 cm in total length. Legs and claws are massive, covered in dense bristles. Grows to 8-10 cm.

Social Behavior: Highly active, strong, and destructive. Capable of knocking over unsecured rockwork or corals. Shows a territorial and somewhat aggressive temperament compared to dwarf species.

Coloration and Sexual Dimorphism: Bright red or reddish-orange body coloration. Covered in prominent, dense golden-brown sensory bristles. Eyes are dark on red-and-white striped stalks. No visible sexual dimorphism.

Tank Setup: Requires a large tank of 40-50 gallons or more. Rockwork must be very stable and secure. Provide a deep sandy substrate and plenty of open walking space.

Diet and Feeding: Voracious omnivore. Consumes frozen mysis, krill, chopped mussels, clams, and fresh fish chunks. Readily accepts large sinking pellets and seaweed sheets.

Water Quality: Reef parameters. Salinity SG 1.021-1.025, pH 8.1-8.4, temperature 22-28°C. Highly sensitive to copper treatments and elevated nitrates.

Compatibility and Tankmates: Not reef-safe with small invertebrates. May prey on large live snails, starfish, and small sleeping fish. Keep only with large, robust fish.

Aquarium Breeding: Microscopic larval stages are pelagic and complex, and do not survive standard home aquarium filtration systems.

Risks and Diseases: Low iodine or calcium leading to failed molts. Lack of suitable large replacement shells (e.g. Turbo or Conus) causes high stress.