#limacia cockerelli

Limacia cockerelli is a dorid nudibranch that grows to be about 2.5cm long and lives in intertidal and subtidal areas from Alaska to Mexico. Though the long papillae are similar to the cerata in aeolid nudibranchs, this species still has a tuft of gills on its back (not visible in the photo), characteristic of dorids.

Photo source - Ken-ichi Ueda