@dejongha posted this special photo of a ‘Blue Sea Dragon’ spotted at Stilbaai.

Here are some more information: Glaucus atlanticus, more commonly called the “blue dragon,” the “blue angel,” the “sea swallow,” or the “blue sea slug,” is an unusual mollusk devoid of a shell. The brilliant blue and silver markings provide contrasting camouflage for the creature through counter-shading, allowing the Blue Dragon to be camouflaged both above and below. The vivid colors also warn of its extremely venomous nature. Common for slugs, the Blue Dragon has a singular muscular foot and rhinopores that provide sensation. It spends most of its life floating upside-down on the surface of the water due to a gas-filled sac in its stomach. These tiny nudibranchs can have up to three sets of long, black cerata (appendages on either side of its body) which can be utilized for respiration, digestion, and protection from predators by storing venom.
Typically only an inch long in length, the miniature creature has never been documented to grow more than 1.2 inches and is usually very slim and sleek. They reproduce as hermaphrodites, as they all have both female and male reproductive parts, and both mating partners will produce egg strings. These eggs are typically laid on drift wood or the carcasses of their parents’ kills where they grow and develop air sacs of their own. The Blue Dragon is in no danger of extinction as the population thrives in every location. Accustomed to tropical, warm waters, the Blue Dragon can be found along the coasts of South Africa, Australia, and parts of Europe. This tiny sea slug is well-known among divers, swimmers, and surfers in those regions because while small, it packs a mean punch. (www.reefnation.com)