Trapania pallida is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.
[2] This species was first described from Plymouth, England and it is found as far north as western Scotland.
[3] It has subsequently been reported from Atlantic coasts as far south as Portugal and in the Mediterranean Sea as far east as Cagnes-sur-Mer.
There is a white stripe along the tail, starting somewhere behind the gills and running to the tip.
Trapania pallida feeds on Entoprocta which often grow on sponges and other living substrata.