Glossodoris rufomarginata, commonly called white-margin sea slug or caramel nudibranch,[2] is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.

[2][4] The background colouration of the entire body is whitish with the foot and the dorsal surface speckled with a dense coat of tiny red to orange-brown dots that give the impression at first glance that the animal is brown.

The edge of the mantle is well developed and wavy with a broad white band with a red to orange-brown outer border.

The rhinophores and branchial plume are retractable[2] with a red to orange-brown colouration, a white median line on the rhinophores and a white highlight on the gill axes.

[5] Glossodoris rufomarginata is active in the daytime[5] and can be easily met on or in close proximity to its favourite food source which are some black sponges of the family Thorectidae,[2][6]