Red Ridged Clinging Crab

Geographical Origin and Habitat: Common in the tropical and subtropical Western Atlantic, from North Carolina and Florida through the Gulf of Mexico to Brazil. Inhabits shallow coral reefs and rocky areas.

Taxonomy: Member of the family Mithracidae. Features a rounded, bumpy carapace measuring about 3-4 cm in width. Has strong legs and robust claws with spoon-like tips adapted for scraping algae.

Social Behavior: Generally peaceful and primarily nocturnal. Prefers to hide under live rock or inside crevices during the day. May show territorial aggression toward similar crabs.

Coloration and Sexual Dimorphism: Carapace and legs are solid reddish-brown, brick-red, orange-red, or purplish. Adult males develop significantly larger and more robust claws than females.

Tank Setup: Suitable for aquariums of 10-12 gallons or larger. Provide plenty of live rock with deep crevices and caves for day shelter. Does not require empty shells.

Diet and Feeding: Primarily herbivorous. One of the few predators of nuisance bubble algae (Valonia). Also consumes green hair algae, film algae, detritus, and sinking pellets.

Water Quality: Stable reef parameters: SG 1.020-1.025, pH 8.1-8.4, temperature 22-28°C. Highly sensitive to copper treatments and elevated nitrates.

Compatibility and Tankmates: Reef-safe. Compatible with peaceful reef fish and corals. May occasionally nip at small bottom-dwelling fish or corals if underfed.

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

Risks and Diseases: Molting failure due to calcium, magnesium, or iodine deficiencies. Underfed specimens may nip at LPS coral polyps or small invertebrates.