Gumboot Chiton

Authors:  Adam Kitzler and Niko Kruzel

Common Names:  Gumboot chiton, giant Pacific chiton, giant red chiton, the wandering meatloaf

Scientific Name: Cryptochiton stelleri

Size Range: Up to 13 inches (33cm) in length

Identifying features:  Gumboot chitons have an orange to yellow underside and their skin is normally a dark orange to reddish brown. Unlike normal chitons the eight bony plates on its back are concealed under tissue (girdle).  The gumboot chiton is the largest chiton in the world and has no eyes or tentacles; but sensory cells to help it navigate.  It is very slow.

Habitat: Gumboot chitons may be found up to 65ft (20m) deep but can also be found on the beach during a very low tide.  They stick onto rocks using there large foot so they don’t get swept off by the tide or large waves.  They exist from the central coast of California up to Alaska, across the Aleutian Islands and down to southern Japan.

Food: Gumboot chiton are herbivores and eat red algae and other seaweeds.  They feed nocturnally with a radula.  The radula contains two rows of magnetite-tipped teeth that scrape algae off the surface of rocks.  The radula resembles a sort of zipper and the teeth of the radula are one of the hardest known materials produced by a living creature.

The mouth of Cryptochiton stelleri showing the teeth of the radula

Photos and video by D. Young

Thanks to Brent Gowan of the University of Victoria, British Columbia for permitting us to use his Scanning Electron Microscope (SEM) images of the gumboot chiton radula.