Trapania palmula is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.
It is also found in Indonesia and southern Japan.
[2] This species of Trapania is unusual in having raised rounded tubercles all over the body.
The lateral papillae have a patch of white surrounding a blue diagonal streak.
[2] Trapania palmula feeds on Entoprocta which often grow on sponges and other living substrata.