Chitons: Colorful and Unique Sea Creatures

What are chitons? Have you seen one? Are there some good things we need to learn about these creatures? Are there some useful things we need to know about them?

Well, these beautiful and colorful sea creatures called 'chitons', pronounce as kai-tnz, are small to large, primitive mollusks. There are 900 to 1,000 extant species of chitons. Other common names for these creatures are sea cradles and coat-of-mail shells. Chitons have a shell which is composed of eight separate shell plates or valves.

Here are some notable and colorful species of chitons.

Lined Chiton (Tonicella lineata)

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Lined Chiton is a very colorful species, having blue, purple or black straight or zigzag lines on each of the eight valves. The background color of the valves is often brown or red, but can also be bright blue or yellow to orange. The girdle is hairless and brown to red or pink, often with regular yellow or white patches. This species grows to 5 cm in length.

Their natural range stretches from the Aleutian Islands of Alaska to San Miguel Island of California, as well as the Sea of Okhotsk of Russia and northern Japan. This species has also been found in Puget Sound, Washington on floats. It has been recorded from a depth of 30 m to 90 m (100 - 300 feet).

Blue-lined Chiton (Tonicella undocaerulea)

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The beautiful Blue Lined Chiton has a head plate with zigzag white concentric lines without a dark border. It commonly has bright electric blue stripes and flecks. The girdle is hairless and brown to red or pink, often with yellow or white mottling. Its natural range stretches from Kodiak, Alaska to Point Conception, California. This chiton grazes on corralline algae.

Flame-lined Chiton (Tonicella lokii)

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Flame-lined Chiton is also commonly called Loki's Chiton. Like most chitons, Loki's Chiton has blue, white, purple or black zigzag lines on each of the eight valves. The background color of the valves is often brown or red, but can also be bright blue or yellow to orange. The girdle is hairless and brown to red or pink. It has radiating bands and often bears a yellow or white broken concentric line, alternating with radiating bands.

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Lined Chiton is extremely similar but does not have radiating bands on the girdle. Blue-lined Chiton is also very similar but does not have the radiating bands on the girdle and also lacks a dark border to the concentric blue lines on the anterior plate.

Red-flecked Mopalia (Mopalia spectabilis)

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The Red-flecked Mopalia is a chiton that has a central area of plates 2-7 pitted in longitudinal rows. The girdle commonly banded light orange and brown. This species nearly always exhibits bright turquoise zigzag markings. The girdle bears prominent hairs that are plumed and are said to look like small "bottle brushes".

Its natural range stretches from Kodiak Island, Alaska to Baja California. It is commonly found under ledges and on the bottoms of rocks in intertidal waters to a depth of 10 m (33 feet)

Butterfly Chiton (Chyptoconchus porosus)

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The brightly colored Butterfly Chiton is a species of large chiton or "coat of mail shell" that has a peculiar physical appearance compared to other species of chiton. Its valves are completely covered by the mantle.

Magnificent Chiton (Chiton magnificus)

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Chiton magnificus is a species of edible chiton. Chiton magnificus' distribution ranges from the Galapagos Islands at the equator to Cape Horn at 55º south. This species is found intertidally.

Fuzzy Chiton (Acanthopleura granulata)

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West Indian Fuzzy Chiton is a medium-sized species common within its range in the tropical Western Atlantic, but it is often not noticed, because its color and texture are similar to the rocks on which it lives. It grows to be about 7 cm (3 inches) in length. The girdle is densely spiky and usually has a few black bands. The surface of the valves (or plates) in this species is almost always quite heavily eroded, but when not eroded, the valve surface is granulated. The valves are thick and heavy. This chiton occurs from southern Florida to Mexico, south to Panama, and in the West Indies. This species lives on rocks very high in the intertidal zone. It can tolerate a lot of sun.

Australian Chiton (Ischnochiton australis)

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This Australian Chiton is found near Clydes Island, Tasmania. This species ranges from 70-90mm and they are usually found under stones on the lower shore.

Gumboot Chiton (Cryptochiton stelleri)

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Another species of chiton with a peculiar physical appearance compared to other chitons is the Gumboot Chiton. Unlike most chitons, the gumboot's valves are completely hidden by its leathery upper skin or girdle, which is usually reddish-brown or brown in color, or occasionally orange. It is also known as the Giant Pacific Chiton and it is considered the largest of the chitons growing up to 33 cm or 13 inches. It is found along the shores of the northern Pacific Ocean from Central California to Alaska, across the Aleutian Islands to the Kamchatka Peninsula and south to Japan.

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It's belly-up at low tide and it is about a foot long.

More species, photos and tidbits:

Suck-rock Chiton (Chiton tuberculatus)

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A chiton creeps along slowly on a muscular foot, and can cling to rocks very powerfully, like a limpet.

Mossy Chiton (Mopalia muscosa)

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The foot of the chiton is prepared in a manner similar to abalone.

Rosy Slender Chiton (Stenoplax fallax)

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Chitons are eaten in Tobago and were eaten by Native Americans of the Pacific coasts of both North and South America.

Conspicuous Chiton (Stenoplax conspicua)

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Some chitons exhibit homing behavior, returning to the same spot for the daylight hours and roaming around at night to feed.

Woody Chiton (Mopalia lignosa)

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Chitons as a molluscan class are exclusively and fully marine animals.

Veiled Chitons (Placiphorella velata)

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Chitons are found in all the oceans of the world. They live in cold water and in the tropics.

Hope you enjoyed this. Thank you!

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