Blood-spotted ardeadoris
Ardeadoris cruenta, formerly Glossodoris cruenta: a pale chromodorid nudibranch with a frilled yellow border and a ring of blood-red spots.
Ardeadoris cruenta is a chromodorid nudibranch described by Bill Rudman in 1986 as Glossodoris cruenta, from Osprey Island on the Great Barrier Reef. Johnson and Gosliner moved it to Ardeadoris in 2012 on DNA evidence. The species name is Latin for stained with blood, and it refers to the red spots on the back. Animals reach at least 50 mm.
The body is a pale lemon or cream colour, and the frilled mantle and the edge of the foot are bordered with bright yellow and a line of white. The red spots sit in a loose ring on the back, just inside the pale band that runs along the mantle edge, and they are what separate it from Ardeadoris rubroannulata, a similar animal without them. The gill and rhinophores are the same pale colour as the body, although some variation between animals has been recorded. The mantle is thin and deeply folded, and in the animal photographed here it is curled into loops at the front and sides.
Like other chromodorids it feeds on sponges and stores the sponge’s chemical defences in glands along the mantle edge, and animals have been photographed releasing mucus from these glands. The red spots are generally read as warning colour. Records come from the Great Barrier Reef, the Philippines, the Lembeh Strait, East Timor and the Solomon Islands, and it is described as not common.
The Avern’s ardeadoris is white with a red border, and the egret nudibranch is white with a plain yellow border and no spots.
Where to find:
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.
