This is identified as Goniobranchus sp. 1 in Gosliner et al (2018). I've always thought its external surface reminded me more of some Verconia or Mexichromis. I wonder where the molecular data falls. Several have observed on sponges near Tulamben.
An egg mass of this nudibranch is at upper left.
Created 20 May 2019
Updated 17 December 2022