A large sand-dwelling sea slug with orange-tipped papillae, out on open ground at night.
A large sea slug, commonly 8 to 12 cm and recorded to about 15, translucent white to pale grey with a broad orange to yellow margin and rows of tall papillae along the back and around the edge, each tipped in orange or violet. The head carries a wide fringed oral veil and the rhinophores sit well forward. Nothing else of this size on open sand looks like it, and the combination of the fringed veil and the papillate margin is enough on its own.
It lives on and in soft sediment rather than on hard ground, and is usually found ploughing across open sand with the front of the body partly buried. Published feeding records are of burrowing brittle stars, taken below the surface. Lifted off the bottom by surge or by a diver’s wash it swims, flexing the whole body from side to side, and it can cover several metres that way before settling again.
Most sightings are on night dives, and the animal is not reliably present at any depth or season: a run of dives can pass without one and then produce two on the same stretch of sand. Recorded from about 5 to 30 m on sand and silt.
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.
