Dirona picta

Dirona picta, common name colorful dirona, is a species of sea slug, an Eastern Pacific Ocean nudibranch, a marine, opisthobranch gastropod mollusk in the family Dironidae.

[1] This marine species occurs from Northern Oregon, USA to Baja California Sur, Mexico.

Also reported from Japan.

[2]

Dirona picta from Santa Cruz, California head-on view