Mossy Chiton (Mopalia muscosa)

Description: Mossy chitons are masters of camouflage. Like all chitons, they have eight plates that are typically a tan, brown, or olive tone that blends in with the rocks and other tide pool creatures. Mossy chitons are named for the fuzzy moss-like hairs that cover their girdle (the flesh that wraps around the edge of their plates). They are usually between 3 to 10cm long and attach themselves to rocks in the intertidal zone. Although difficult to spot, this species is abundant at Haystack Rock. The mossy chiton and its close relative the hairy chiton (Mopalia ciliata) look very similar to each other. When identifying the mossy chiton, look for thick stiff hairs compared to the longer softer hair of the hairy chiton.

Habitat: Mossy chitons range from Alaska to Baja California, Mexico and prefer the lower intertidal zone of rocky beaches. At Haystack Rock mossy chitons are often found on the underside of large boulders.

Diet: Like other chitons, mossy chitons eat algae.

Tide Pool Tidbits:

• Mossy chitons will only move under certain conditions: while it is nighttime and while the chiton is wet or submerged underwater.

• The plates on a mossy chiton often have other organisms such as algae and barnacles growing on them.

• Mossy chitons each have their own “territory” that they occupy where they forage.

Reference: Biodiversity of the Central Coast