Nudibranch - Doriprismatica sedna (ID updated to Chromolaichma sedna)

On a dive trip focused more on looking for the big stuff such as Sharks, Mantas and Dolphins, it was a nice surprised to be shown this small sized Nudibranch of around 1.5 cm in size by our dive guide. It was also a challenge to take pics of it as close on the walls, we get hit by big swells.

This species was previously known as Glossodoris sedna and was later reclassified to Doriprismatica sedna in 2012.
(Further update, reclassified to new Genus Chromolaichma, new ID should be Chromolaichma sedna)