Blue Leg Hermit

The blue leg hermit crab, scientifically known as Clibanarius tricolor, is a tiny marine decapod crustacean native to the shallow, tropical intertidal waters of the Caribbean, Florida Keys, and Gulf of Mexico. Reaching an average adult size of only 0.5 to 1 inch (1.2 to 2.5 centimeters) in length, it is one of the smallest and most popular hermit species in the marine aquarium trade. It is easily distinguished by its striking royal blue legs, which are accented with tiny red bands near the joints and bright orange antennae. These miniature scavengers are widely utilized as foundational clean-up crew members due to their tireless foraging and ability to squeeze into tight rock crevices that larger scavengers cannot reach. They actively pick at nuisance green hair algae, film algae, cyanobacteria, detritus, and uneaten fish food resting on live rock and substrate. Because of their tiny stature, they are completely safe around living corals, clams, and sessile invertebrates, making them ideal for reef systems of any size.

In a home saltwater aquarium, Clibanarius tricolor is peaceful and very easy to care for, thriving in groups where they continuously work over live rock structures. However, as they grow, they must molt and find larger housing; aquarists should scatter various empty micro-snail shells across the sand bed. Failing to provide adequate replacement shells may occasionally prompt these small hermits to attack small herbivorous snails, such as Cerith or Nerite snails, to take their shells.