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It was originally misidentified and posted at these websites as Kaloplocamus ramosus (Cantraine, 1835) [Doris], which has the same body colour, but differs by relatively short lateral and velar appendages, which are only moderately branched.
Kaloplocamus ramosus was initially described from the Mediterranean Sea, and has since been reported from South Africa, West Africa, Japan, Eastern Australia, New Zealand, and Hawai'i.
Let me quote IPN at page 106: "This widespread species needs further study to determine whether it is a single species or a complex of several distinct ones."
Gosliner, Terrence M., David W. Behrens & Ángel Valdés. 2008. Indo-Pacific Nudibranchs and Sea Slugs. Sea Challengers Natural History Books.
Gig Harbor, Washington. 426 pp.