A flat mottled dorid that sheds pieces of its own mantle margin when it is disturbed.
A broad flat dorid to about 10 cm, the mantle firm and granular and mottled in brown, cream, grey and black in a pattern that reads as blotches rather than as lines or spots. The mantle skirt extends well beyond the foot on all sides, so the animal lies almost flush with the ground, and the gill plume folds down into a pocket and disappears when the slug is touched or lit hard.
The defence is worth knowing because it is visible. Disturbed animals autotomise the outer part of the mantle margin, shedding fragments that continue to twitch on the bottom while the slug moves off, and a specimen with a ragged, unevenly edged skirt has usually done this before. The shed tissue is thought to be distasteful, and the margin regrows.
It is a night animal for the most part, found on rubble, sand and sponge-covered rock, and its colouring against that ground is good enough that it is normally spotted moving. Several similar flat brown dorids share the habitat and are not separable in a photograph with any confidence. Recorded from about 3 to 30 m.
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.
