A drab, blotched fish that lies on its side under ledges by day. Its skin mucus is toxic and lathers in water, which is where the name comes from.
To about 33 cm, drab brown blotched with darker patches, with a projecting lower jaw and a habit of lying on its side under a ledge. It looks unwell and it is not; that is how it rests.
The skin produces a mucus containing grammistin, which lathers in water and gives the family its name. It is a chemical defence: the fish is unpleasant to take in the mouth, and a predator that has tried one does not try another. It irritates skin and eyes and it matters only if the fish is handled, which is another reason not to. It is nocturnal, and by day the way to find one is to look under ledges for a fish that appears to have given up.
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.
