Hypselodoris bullockii is a species of colourful sea slug or dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.

Hypselodoris bullockii is quite pale purple in colour. It has been mistaken for a number of other species. These include the closely related species Hypselodoris variobranchia and Hypselodoris violacea as well as the unrelated species Hypselodoris iba. Hypselodoris apolegma, which looks similar to this species (and is distinguished by a reticulate pattern gradually merging in to the pinkish purple ), was previously assumed to be possibly a different colour form of H. bullockii. However, molecular phylogenetic data confirm the distinction of the many species.

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