Trapania graeffei is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.[1]
This species was described from Tergeste, Italy. It does not seem to have been seen since 1879.
This goniodorid nudibranch is translucent white with a rose-red tint and a scattering of brown spots all over the body. The rhinophores and gills are rose-red. "Color pellucide et clare rosaceus, supra punctis et maculis minutis fuscis ubique sparsis; appendices rhinophoriales et branchiales rosaceae."
Like other species in this genus Trapania graeffei probably feeds on Entoprocta, which often grow on sponges and other living substrata.