Goniobranchus family

A bunch of different Chromodoris Nudibranchs got moved to the Goniobranchus family as a result of recent scientific research.

The faithful Goniobranchus is an interesting name for a nudibranch; to what (or whom) is it faithful?

Thank you Thomas, for this rare sighting from Koh Tao.

Thank you Lawrence for the incisive identication, as there are a few similar looking species.

Seen at a few locations around Koh Phangan, and nowhere else so far.