Intertidal Invertebrates of the Monterey Bay Area, California

Compiled & photographed by Gary McDonald, Long Marine Laboratory, University of California, Santa Cruz

Description: Ground color highly variable, most commonly white to brownish, but individuals which are dull grey, mauve, rose, or pink have been observed. The somewhat flattened cerata extend anterior of the rhinophores, and densely cover the dorsum except in the cardiac region; core of cerata usually brownish to mauve or umber, but quite variable. Area between oral tentacles and rhinophores with a triangular to crescentic patch of encrusting white to cream, which may be prolonged onto dorsal surface of oral tentacles; area of similar pigment occurs posterior of rhinophores and extends to cardiac region.
Size: Typically about 20-30mm in length, but may exceed 100mm in length.
Notes: Feeds on various species of sea anemones, such as (but not limited to): Anthopleura artemisia, Anthopleura elegantissima, Anthopleura xanthogrammica, Epiactis prolifera, Metridium senile, Tealia crassicornis.