Two-spot Hermit Crab

Geographical Origin and Habitat: Indo-Pacific Ocean, distributed along the coasts of southern Japan, Indonesia, and Australia. Typically lives in areas rich in coral rocks and sheltered sandy crevices.

Taxonomy: Belongs to the family Diogenidae. Features a robust protective exoskeleton with claws developed for defense and burrowing. Size up to 2.5 cm.

Social Behavior: Predominantly solitary or gregarious depending on shelter availability. Plays a crucial ecological role as a herbivore.

Coloration and Sexual Dimorphism: Coloration varies from brown to bright red. Sexual dimorphism is not highly pronounced externally, except for abdomen shape or claw size.

Tank Setup: Requires a reef aquarium with plenty of live rock. For hermit crabs, it is essential to provide empty gastropod shells of various sizes to support growth.

Diet and Feeding: Herbivorous/Detritivorous. Consumes filamentous algae, diatoms, cyanobacteria, and food debris.

Water Quality: Standard marine values: temperature 20.0-26.0°C, pH 8.1-8.4, constant salinity, and absolute absence of copper in the aquarium.

Compatibility and Tankmates: 100% reef-safe. Compatible with almost all peaceful tankmates. Avoid predatory fish that feed on crustaceans (e.g. puffers or lionfish).

Aquarium Breeding: Sexually reproducing species. Larvae undergo pelagic zoeal stages and require phytoplankton.

Risks and Diseases: After molting, the exoskeleton is soft. The animal remains hidden under rocks for several days. High sensitivity to heavy metals (copper) and sudden osmotic shocks.