Mossy Chiton

How to Distinguish from Similar Species: The other Mopalia species with hairs on the girdle, such as Mopalia lignosa, have thinner, flexible hairs.

Biology/Natural History: Moves at night at high tides. This species homes to a special place on the rock after each trip. Home ranges of different individuals usually do not overlap. Permanently submerged individuals in tidepools may not home. Feeds primarily on the red alga Mastocarpus papillata and Endocladia muricata, green alga Cladophora. Larvae will settle on rocks or shells covered with an algal film.

On rocks, especially in areas of low to moderate surf. Also found in estuaries.

Geographical Range: Queen Charlotte Islands, Canada to Isla Cedros, Baja California

Depth Range: Middle and low intertidal

This chiton has a wide girdle covered by a thick mass of long, mossy , stiff, rubbery hairs. The girdle is about the same width all around, and no plate is dramatically larger than the others. The dorsal surface of the girdle, between the hairs, is not especially granular. Body to 9 cm long but more often is around 3 cm. Valves dull brown, dark olive, or gray; may be eroded or overgrown with algae. Barnacles may even settle on the plates.