The Goniobranchus albopunctatus or White Spotted Nudibranch is not commonly seen by snorkelers or divers.  The individuals  photographed below differ significantly in colour, and their bodies can indeed vary from yellowish to reddish — the lighter ones sometimes being mistaken initially as Imperial Nudibranchs, and the darker ones as Red   Both individuals documenter here were both found in North Kihei Maui. Approximately 2″ (50 mm) but can be up to 2.5 inches. For more information on their taxonomic history, see Sea Slugs of Hawaii.