Yellow & Blue Sheep

Costasiella sp. is a species of sacoglossan sea slug, a shell-less marine opisthobranch gastropod mollusk in the family Costasiellidae.

Description

It is characterized by an yellow-orange body with minute dark gray/black spots.The cerata are basally yellow-orange with minute gray/black spots, then yellow-orange band, then black band, then broad bright blue band, then black and yellow-orange bands again, the apices are dark blue to black.

The head is yellow-orange with two longitudinal black and blue patches. The rhinophores are black with a pale orange stripe, fading into black towards the tip. The eye spots close together between the rhinophores.

Distribution

Indo-West Pacific.

Habitat

It feeds on green algae.