This is one of
the larger nudibranchs seen at Julian Rocks and it has six gills on
its back. Once you have seen this nudibranch swimming it is clear
where its common name comes from as it mantle margins wave up and
down like the skirts of a Spanish Dancer.
The egg ribbons (photo on the right) are very easily recognised by
the pink/orangy colouring.
Note: please don't try and pull this nudibranch off the substrate
it is resting on in order to make it swim as you can injure or even
kill it by doing so.