It took a little time to identify the first individual, spotted in 2016, as it turned out to be an unusual range extension. The waters off the Pacific West Coast were warmer than usual between 2014 & 2017 and this Blood-spot Aldisa, usually found no further north than Oregon, was discovered off of British Columbia.  Unlike its southern counterpart, it lacks the blood spots on its mantle, making identification that much more difficult. It may, at some time in the future, become its own special species.  These dorids can grow to 30 mm, much larger than the Rostanga pulchra that it is often mistaken for.  The Sea Slug Forum has a discussion about the complexity of identification and questions its presence in British Columbia as early as 2005.  Since finding the original animal in 2016, I have found several in varying colours off of Pender Island, B.C., so perhaps they are establishing themselves now — one of them was much more of a yellow-gold colour than orange, and they varied in size from 10 mm to 30 mm.