Chitons - Schizoplacidae, Tonicellidae

Schizoplacidae

preserved specimen found intertidally

Schizoplax brandtii (Middendorff, 1847)
very low intertidal to 40m size to 2cm
central BC to Alaska, Bering Sea & Sea of Japan
This is rarely seen intertidally. It is most common in oyster beds and among growths of algae. It has brown striping over a blue background. The plates are split down the mid-line by cartilage-like tissue which is best seen under magnification.

all photographed intertidally
Cyanoplax dentiens (Gould, 1846)
Gould's Baby Chiton *
intertidal to 6m northern Mexico to southern Alaska size to 2.7cm
This is a common intertidal species although often hard to spot due to its small size. It is variable in color
but is most commonly greenish-gray to brown. White flecks or blue-green dots are also typical.
(previous names - Lepidochitona dentiens, Isnochiton dentiens)

Tonicella insignis (Reeve, 1847)
White-Line Chiton
intertidal to 50m northern Oregon to northern Alaska size to 6cm
This species is rarely found intertidally. It is reddish-brown with lighter-toned
wavy lines across the width of the plates. The girdle is light brown.

Boreochiton cf. beringensis
(Yakovleva, 1952)
intertidal to 300m size to 3.5cm
central Washington to northern Alaska; Arctic
This is infrequently found intertidally. It is bright to dull red or pink and has red and white wavy lines. The girdle is orangish-red.
(Photo is of preserved specimens.)

Tonicella lineata (Wood, 1815)
Lined Chiton *
intertidal to 90m southern California to northern Alaska, Japan & Siberia size to 5cm
This is a very common intertidal species. The background color is orangish with zigzag lines of reddish-brown and white (or blue) running down the plates. Some plates may also be a solid color, usually a reddish-brown. The girdle is banded and also may vary in its colors.

Click on photo to enlarge. Scale line in photo equals 1cm unless otherwise specified.
* Species which are commonly encountered on the beach.

preserved specimen photographed intertidally photographed subtidally

Tonicella undocaerulea (Sirenko, 1973)
Blue-Line Chiton
intertidal to 50m southern California to central Alaska size to 5cm
This is occasionally found intertidally. It has a light orangish background with distinctive blue or white wavy lines. There are usually streaks of maroon edging the wavy lines. Some plates may be almost solid in color. The girdle is banded.

Tonicella cf. venusta Clark, 1999
intertidal to 140m northern Mexico to southern Alaska size to 1.7cm
This tiny species is rarely found intertidally. It has a light orange or pink background with white zigzag lines. Light dash markings along the center of the plates separate this species from the others.
The girdle appears sandy. (The photo is of a preserved specimen and the ID is not confirmed.)

Chitons (Polyplacophora)

Family Schizoplacidae & Tonicellidae