Nothing else on shallow silt carries the branched papillae that give it its outline.
A sea hare to about 12 cm with no visible shell, the whole body covered in long branched papillae that give it a shaggy, ragged outline. Colour is grey-green to olive-brown with dark mottling and scattered small iridescent blue spots. Dolabella auricularia, the other common sea hare on these sites, is a smooth wedge-shaped lump by comparison, and nothing else on silty sand carries papillae like these.
Grazes the surface film of diatoms and cyanobacteria on shallow silt, and often occurs in aggregations of many animals over a small patch of ground, so numbers vary a great deal from one visit to the next. A disturbed animal releases purple ink. It is a warm-water cosmopolitan, recorded from the Indo-Pacific, the tropical Atlantic and the Mediterranean, where it is a comparatively recent arrival.
Recorded from the intertidal to about 12 m on sheltered silt and weed.
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.
