Intertidal Invertebrates of the Monterey Bay Area, California

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

Description: Ground color varies from clear, light orange to darker orange, yellow brown, or yellow. In large individuals the dorsum bears numerous round to oval, pale blue to almost white spots, sometimes with more numerous small, dark brown dots. Pallial ridge bears 4-6 yellow to orange or vermilion, prolonged processes which bear small branches or tubercles, and may be white tipped; frontal veil bears 7-12 similar processes. Rhinophores bear 15-20 lamellae, colored as body or slightly darker. Branchial plumes 5-7, tripinnate, white to orange.
Size: Typically 20-30mm in length, but may exceed 180mm.
Notes: Feeds on several species of erect bryozoans such as: Bugula mollis, Caulibugula ciliata, Cauloramphus spiniferum, Crisia occidentalis, Membranipora membranacea, Scrupocellaria californica, & Tricellaria sp. Formerly, the large, lighter colored individuals, which were usually found on kelp, were thought to be a separate species: Triopha grandis.