Grey Side-gilled Sea Slug

Pleurobranchaea maculata - Pleurobranchaea is a genus of sea slugs, specifically sidegill slugs or notaspideans. These are marine gastropod molluscs in the family Pleurobranchaeidae. The genus is differentiated from other sidegill slugs by its rhinophores, which are well separated, rather than being joined under the notum. This genus has recently been coined sea owls which is the common name in Japanese for Pleurobranchaea japonica.