Lamarck's Pebble Crab

Geographical Origin and Habitat: Widely distributed throughout the tropical Indo-Pacific, from East Africa and the Red Sea to Australia, southern Japan, and Polynesia. Settles on shallow rocky reefs and coral rubble.

Taxonomy: Member of the family Xanthidae. Features a smooth, rounded, and slightly flattened carapace measuring about 2-3 cm in width. Claws are short, thick, and symmetrical with dark tips. Grows to 2.5 cm.

Social Behavior: Peaceful, shy, and primarily nocturnal. Spends the daytime hidden under live rocks or inside dead coral branch crevices. Harmless to peaceful tankmates.

Coloration and Sexual Dimorphism: Carapace color varies from light brown, beige, or cream to reddish or pale orange with irregular darker brown mottling. Claws have distinct dark brown or black tips. No visible sexual dimorphism.

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

Diet and Feeding: Omnivorous scavenger and detritivore. Consumes microalgae, organic detritus, small worms, and leftover fish food. Accepts sinking pellets and chopped frozen foods.

Water Quality: Stable marine 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: 100% reef-safe. Great clean-up crew member. Compatible with peaceful reef fish and corals. Avoid keeping with large predatory fish.

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. Highly sensitive to copper treatments and sudden osmotic shocks.