Hairy Chiton (Mopalia ciliata)

Other Names: Northern hairy chiton, hairy Mopalia

Description: Hairy chitons have a very similar appearance to mossy chitons (Mopalia mucosa). They can grow up to 7.5 cm long, have eight distinctive plates with a fuzzy girdle around the edge of their oval bodies. Hairy chitons can be distinguished from mossy chitons by the hairs on their girdle and their colors. Coming in a broad range of shades, the hairy chiton can have an orange, green, white, or gray tinted plates and mantle. The hairs on a hairy chiton’s mantel is typically thinner compared to a mossy chiton.

Habitat: The hairy chiton ranges from the Aleutian Islands in Alaska to Baja California, Mexico. They prefer mid to low intertidal rocky environments. At Haystack Rock it is easiest to spot them on boulders on the South side of the rock or near the needles.

Diet: Like other species of chiton, hairy chiton scrape algae off the rocks where they live. They are also known to eat hydroids, sponges, and bryozoans.

Tide Pool Tidbits:

• At just 16 days old a hairy chiton will resemble a tiny version of an adult.

• The interior side of a hairy chiton’s plates often have a pink and/or blue color to them.

• Hairy chitons are generally nocturnal grazers but they will occasionally feed on days when it is overcast.

Reference: Walla Walla University