Lepidozona mertensii (Middendorff, 1847)

Common name(s): Merten's chiton, mottled red chiton, red chiton

Synonyms: Ishnochiton mertensii Lepidozona mertensii
Order Neoloricata 
Suborder Chitonina 
Family Ishnochitonidae 
Lepidozona mertensii, 3.4 cm long, found under rocks at Sares Head.  Anterior end (head and plate 1) is to the left.
(Photo by: Dave Cowles, July 2012 )

Description:  In this chiton, the dorsal surface of the girdle is covered with overlapping oval scales (photo), but has no spicules nor hairs (spicules may be along the margin).  Plate 1 is about as long as plate 8.  Plates 2-7 have nodular bumps on the lateral areas (photo), and the central areas have longitudinal ridges which diverge anteriorly (photo).  Some pits may be between the ridges.  Valves (plates) are reddish, brownish, or occasionally greenish-purple.  Girdle with bands of yellow and red.  May have white blotches.  Length to 4 cm, and roughly half as wide.

How to Distinguish from Similar Species:  This is the only common intertidal chiton in this area with its girdle covered with scales (some others are subtidal).

Geographical Range:  Northern Alaska to northern Mexico; Japan

Depth Range:  Intertidal to 90 m

Habitat:  Usually lives under rocks.

Biology/Natural History:  Females of this species lay their eggs in cases.  The bryozoan Farella elongata sometimes attaches to the ventral surface of the girdle.



Dichotomous Keys:
  Flora and Fairbanks, 1966 (as Ischnochiton mertensii)
  Kozloff, 1987, 1996

General References:
  Harbo, 1997
  Johnson and Snook, 1955 (as Ischnochiton mertensii)
  Lamb and Hanby, 2005
  Ricketts et al., 1985

Scientific Articles:
Ferreira, A.J., 1978.  The genus Lepidozona (Mollusca: Poluplacophora) in the temperate eastern Pacific, Baja California to Alaska, with the description of a new species.  Veliger 21: pp 19-24
Helfman, E.S., 1968.  A ctenostomatous ectoproct epizoic on the chiton Ishnochiton mertensii.  Veliger 10: pp. 290-291

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:


This view of the head with plates 1-2 shows the overlapping oval scales on the girdle, the globular bumps on the lateral parts of the plates, and the longitudinal ridges in the center portions of the plates which diverge anteriorly.


This view of the posterior end with plates 6-8 shows similar features.  The longitudinal ridges in the central parts of the plates are more clearly visible here.

Authors and Editors of Page:
Dave Cowles (2012):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Salish Sea Invertebrates web site provided courtesy of Walla Walla University