Sally Lightfoot crab

About

The Sally Lightfoot crab (Percnon gibbesi) has a reputation that matches its name. This crab is genuinely fast, flattening itself against rock surfaces and darting between crevices with a speed that can catch you off guard when you first see it move. It's a broadly distributed species found across the tropical and subtropical Atlantic, including the Caribbean and the Canary Islands, typically living in the surge zone and shallow rocky areas where it grazes on algae and organic matter. That algae-eating habit is one reason hobbyists bring it into reef tanks, and it can do a solid job working over surfaces that other cleaners ignore. The flattened body shape isn't just for show. It's an adaptation for slipping into tight spaces and clinging to rocks in high-flow environments, and you'll often find yours tucked into a cave or pressed against the back wall of the tank. Care is rated intermediate for a reason. Larger specimens can develop a taste for things other than algae, including small fish, invertebrates, or coral tissue, so tankmate selection matters. Giving it plenty of rockwork to explore and a good natural food supply keeps it occupied and less likely to go looking for trouble elsewhere in the tank.