non Bergh, 1888 Phyllidiopsis xishaensis is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Phyllidiidae.

[2] Frequently misidentified as Phyllidiopsis striata but that species has been shown to be a completely different animal, a Phyllidiella.

It has been reported from South Africa, Réunion, the Maldives, Malaysia, the Philippines and the Great Barrier Reef, Australia.

[5] This nudibranch has a blue-white dorsum with four longitudinal black lines interspersed with raised ridges.

It is similar to Phyllidiopsis annae except for the colour of the rhinophores, which are black in that species.