Pleurobranchoidea

Pleurobranchoidea
This is a group that is commonly referred to as the “side-gilled slugs” because of the single, plume-like gill located down along the right side between the mantle and the foot. These are soft, plump bodied sea slugs. The shell is never external, and may or may not be present internally. The oral veil is trapezoidal in shape and bears rolled oral tentacles at the lateral edges. They are carnivorous, feeding upon sponges and ascidians. Many are nocturnal feeders.