Pododesmus macroschisma (Gray, 1850)

Common name(s): Alaska falsejingle, Jingle shell, Money shell, Pearly monia, Rock oyster, Abalone jingle, Green false-jingle, Blister shell, False Pacific jingle shell

Synonyms:  Pododesmus macrochisma, Pododesmus cepio, Monia machroschisma
Phylum Mollusca
 Class Bivalvia
  Subclass Pteriomorphia
   Order Ostreoida
    Suborder Pectinina
     Family Anomiidae
Pododesmus macroschisma shell, with the top (left) valve on left and bottom (right) valve on right. 
(Photo by: Dave Cowles, August 2005)
Description:  This unique bivalve species has thin valves, nearly circular in outline.  The right valve is permanently cemented to the substrate (rock, wood, abalone shells, or plastic).  The right valve has a large hole in it near the hinge, through which byssal material cements the bivalve to the rock (photo).  The left valve has a dark muscle scar opposite the perforation in the right shell, and is otherwise polished inside and often bright iridescent green (probably from algae living within the shell).  Flesh is bright orange.  Diameter to 10 cm.

How to Distinguish from Similar Species:  There is no other local species similar to this.  Oysters cement one shell to the substrate but they are much larger, have thick shells, and do not have the hole in the shell through which a byssus attaches.  The rock scallop Hinnites gigantea is larger, has a thicker shell with no hole in it, and has a deep purple stain on the inside of the shell near the hinge.

Geographical Range:  Bering Sea, Alaska to Baja California; Chukchi Sea

Depth Range:  Low intertidal to 90 m

Habitat:  Cemented to rocks, plastic, or wood.  Common on pilings

Biology/Natural History:  Predators include the seastars Evasterias troschelii and Orthasterias koehleri.  Dead shells of this species are often colonized by boring sponges such as Cliona celata var californiana.

The name "jingle shell" comes from the fact that the dead shells make a pleasant jingling sound when struck together.  People often make mobile chimes from them, using the handy byssal hole to hang them.

Pododesmus macrochisma is now an Alaskan species, different from this species.

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Dichotomous Keys:
  Flora and Fairbanks, 1966
  Kozloff 1987, 1996 (As Pododesmus cepio)
  Smith and Carlton, 1975 (As Pododesmus cepio)

General References:

  Gotshall, 1994 (as Pododesmus cepio)
  Gotshall and Laurent, 1979 (as Pododesmus cepio)
  Hinton, 1987 (as Pododesmus cepio)
  Johnson and Snook, 1955
  Kozloff, 1993 (as Pododesmus cepio)
  McConnaughey and McConnaughey, 1985
  Niesen, 1994  (As Pododesmus cepio)
  Niesen, 1997  (As Pododesmus cepio)
  O'Clair and O'Clair, 1998
  Ricketts et al., 1985 (As Pododesmus cepio)
  Sept, 1999

Scientific Articles:

Web sites:

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

These are very common shells attached to subtidal rocks near Northwest Island and Coffin Rocks.

This live specimen shows the living tissue inside

Here is a view of the right valve, with the byssus where it attaches to the rock

Here is a whole live specimen, encrusted with barnacles and bryozoans.

Authors and Editors of Page:
Dave Cowles (2005):  Created original page