About Hermissenda crassicornis (Eschscholtz, 1831)
This species of nudibranch, Hermissenda crassicornis, reaches a maximum length of around 50 mm, which equals approximately 2 inches or 5.08 cm. The body color of this sea slug varies between different localities, but it can always be easily identified by an orange stripe running along its head region, white stripes on its cerata, and additional white stripes that run down its mantle. This nudibranch occurs in the marine region from Kodiak Island, Alaska, down to Northern California. South of Northern California, this species is replaced by the related species Hermissenda opalescens. Hermissenda crassicornis can be found in a wide range of different marine habitats, including the intertidal zone of rocky shores, and it also lives in bays and estuaries.
