This Petrolisthes eriomerus (Flattop Crab) measured about 2" across its carapace.
This poor Petrolisthes eriomerus (Flattop Crab) has only one pincer. The blue line along the edge is something I haven't seen before on this species.
Specimen #: BBEL_0061, Collection Event #: BLIZ_005, Common Name: porcelain crab, Scientific Name: Petrolisthes sp., Magnification: 1.5x, Location: Smithsonian Institution's Field Station on Carrie Bow Cay, Belize
Apparently the hairs on all legs, red spot between fingers, and greenish tint are typical of cabrilloi.
Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They are typically less than 15 mm (0.6 in) wide, and have flattened bodies as an adaptation for living in rock crevices. They are delicate, readily losing limbs when attacked, and use their large claws for maintaining territories.