Photographer: Paul Osmond
(see this users gallery)
The distinctively colored Chromodorididae Nudibranch (Chromodoris kunei) moves across the rich ocean sands at the Tulamben Slopes dive site in Tulamben Bay in Bali, Indonesia. As this nudibranch moves, the mantle skirt undulates as shown here, and this makes it one of the more active and attractive of nudibranch species.
Tulamben Slopes is one of the premier muck diving sites in the world, featuring black sand slopes that are some of the richest in the world.