Intertidal Invertebrates of the Monterey Bay Area, California

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

Description: Ground color pale greyish, with longitudinal black lines of various widths on dorsum and sides. Oblong spots of yellowish-orange occur everywhere between the back lines, which may branch somewhat. Frontal veil bears 4-8 tapered, pointed processes which are orange-yellow medially. Rhinophores bear 8-12 lamellae, and are translucent greyish-white, with a slightly dusky gray hue, each bear a subterminal band of orange-yellow on clavus, and a large triangular spot of like color on in inner surface of shaft near base. Branchial plumes 7-11, unipinnate, dusky greyish, each with an orange spot distally on outer face, a larger spot proximally, and a pale orange spot at base of inner face. There are usually 2-4 extra-branchial appendages which are yellow-orange with greyish-white tips.
Size: Typically about 20mm in length, but may reach at least 38mm.
Notes: Feeds on arborescent bryozoans such as Bugula pacifica; also reported to eat the encrusting bryozoan Membranipora membranacea. Typically found in bays and estuaries rather than in open coast areas.