Giant pacific chiton, gumboot chiton, giant red chiton, moccasin chiton, butterfly shells • Cryptochiton stelleri • Heiltsuk/Haíɫzaqv - ƛ̓íx̌ac̓i
Top left: photo by Sara Wickham. Note how the shell plates are not visible, as they are completely covered by the red girdle. Top right: giant Pacific chiton underwater, photographed by Mike Munroe. Bottom: underside of a giant Pacific chiton. Photos by Kira Hoffman (left) and Josh Silberg.
Identification
The giant pacific chiton is the largest chiton in the world, reaching up to 33 cm long. It is an elongated oval shape, and brown or reddish-brown colour with occasional lighter patches. This colour is from the approximately 20 species of red algae that live on the chiton, and also from the red algae on which the chiton grazes. The girdle has a bumpy texture and completely covers the shell plates, a feature which is unique to this species. The chiton's underside is yellow or orange. Juveniles under 1 cm are yellow all over, with some exposed plates. Adult shell plates can be quite large, are light blue or white and butterfly-shaped, and can sometime be found washed up on shore.
Click here to watch a short video of a grazing giant pacific chiton. You'll be surprised how flexible these creatures are, and how quickly they can move. Compared to some chitons that have been recorded in the same spot for up to 25 years, this one is a speed demon!
Habitat & Range
This chiton is found in intertidal areas and kelp forests to a depth of 20 m. It has been found all along coastlines of the northern Pacific: from Japan to Kamchatka in Russia, along the Aleutian Islands and south to the Channel Islands in California.
Human Uses
Shell plates from this species are commonly found in First Nations middens, as it was a traditional food source. As well, the Haida have a traditional name for large giant pacific chiton individuals, which is sgiidaa and means "lying face down forever."
The giant pacific chiton is the largest chiton in the world, reaching up to 33 cm long. It is an elongated oval shape, and brown or reddish-brown colour with occasional lighter patches. This colour is from the approximately 20 species of red algae that live on the chiton, and also from the red algae on which the chiton grazes. The girdle has a bumpy texture and completely covers the shell plates, a feature which is unique to this species. The chiton's underside is yellow or orange. Juveniles under 1 cm are yellow all over, with some exposed plates. Adult shell plates can be quite large, are light blue or white and butterfly-shaped, and can sometime be found washed up on shore.
Click here to watch a short video of a grazing giant pacific chiton. You'll be surprised how flexible these creatures are, and how quickly they can move. Compared to some chitons that have been recorded in the same spot for up to 25 years, this one is a speed demon!
Habitat & Range
This chiton is found in intertidal areas and kelp forests to a depth of 20 m. It has been found all along coastlines of the northern Pacific: from Japan to Kamchatka in Russia, along the Aleutian Islands and south to the Channel Islands in California.
Human Uses
Shell plates from this species are commonly found in First Nations middens, as it was a traditional food source. As well, the Haida have a traditional name for large giant pacific chiton individuals, which is sgiidaa and means "lying face down forever."
Intriguing Info
The gumboot chiton's girdle may be marked with yellow pits, which are made by a sea snail, the lurid rock snail, which is this chiton's only predator. As well, some marine worms (Arctonoe spp.) and the pea crab Opisthopus transversus can sometimes be found in the grooves between the chiton's foot and mantle. This chiton's radula are covered in magnetite, a hard magnetic material. |
Photos by Jenn Burt: ventral view (left) and dorsal view (right)
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References
Cowles, D. (2005). Cryptochiton stelleri Middendorff, 1847. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 08/06/2013
Harbo, R. M. (1999). Whelks to whales: Coastal marine life of the Pacific Northwest. Madeira Park, BC: Harbour Publishing. P. 125
Gumboot chiton. Monterey Bay Aquarium. Monterey Bay Aquarium Foundation. Accessed 22/06/2013.
Authors and editors of page
Kelly Fretwell and Brian Starzomski (2013).
Cowles, D. (2005). Cryptochiton stelleri Middendorff, 1847. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 08/06/2013
Harbo, R. M. (1999). Whelks to whales: Coastal marine life of the Pacific Northwest. Madeira Park, BC: Harbour Publishing. P. 125
Gumboot chiton. Monterey Bay Aquarium. Monterey Bay Aquarium Foundation. Accessed 22/06/2013.
Authors and editors of page
Kelly Fretwell and Brian Starzomski (2013).