Phylliroidae

Phylliroidae is a family of nudibranchs, shell-less marine gastropod molluscs or sea slugs, in the superfamily Dendronotoidea. They are highly adapted to a pelagic lifestyle and occur in tropical surface waters around the globe. The two genera assigned to this family, Phylliroe and Cephalopyge, are relatively small in size (up to ), slender and highly transparent. They swim by undulating their whole body. Their foot is very small, which helps to reduce drag. They are carnivores that prey on planktonic jelly fish.