Spurilla croisicensisSpurilla croisicensis is a species of sea slug, an aeolid nudibranch. It is a shell-less marine gastropod mollusc in the family Aeolidiidae.DistributionThis species was described as common at Le Croisic, France. It was redescribed under the name Spurilla onubensis.DescriptionSpurilla croisicensis is variable in colour, with this variation being correlated with age.