A solid asymmetrical shell, which is wedge shaped. Greyish-white externally, internally the shell is porcelain white. Shell length to 70mm long.They can be distinguished from Pipi, by the hinge, which is central to the shell.

More Common in South Island to Stewart Island but does occur in the North in some areas. Muddy shore. Low intertidal and shallow subtidal down to 5-10m but more commonly 2-4m. Prefers clean sand. Usually found in the mouths of estauries of inlets.

Filters small plankton out of the water.

Favoured prey of the Black Back Gull (Larus dominicanus), who fly up with the shell and drop it onto rocks to break open the shell. A popular recreational fishery.

Jones, M. B., Marsden, I, D., 2005, Life in the Estuary. Canterbury University Press. NZ Coastal Marine Invertebrates; Vol 1