A fast intertidal crab, brilliantly marked as an adult and near-black as a juvenile.
Intertidal, brilliantly marked, and photographed more than any other Galapagos invertebrate. Adults are red, orange and blue over a dark carapace; juveniles are almost black and cryptic against the lava, which is a straightforward ontogenetic change in a species whose predation risk falls sharply with size.
They are fast and hard to approach, moving over wet rock and across water surfaces. Split-level and over-under frames on the rock at the waterline are the usual approach; underwater sightings are incidental.
Not a Galapagos endemic — the species occurs down the Pacific coast of the Americas — but it is closely associated with the islands in most published material.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
