Naria poraria (Linnaeus, 1758)
Porous cowry or Grape, 10-29mm

Naria poraria is a shallow water shell found commonly from the intertidal reef to depths of about 10m on both lagoon and seaward reefs. It is fairly abundant under large boulders on the tops of large flat-topped pinnacle reefs such as those near Kwadak Island. On the seaward reef, it is often seen at night among the branches of dead branch corals growing on the reef flat above the steep seaward slope. This species has a wide distribution throughout most of the Indo-Pacific.

A pair on the sponge-encrusted undersurface of a large rock.

The shell below was covering a mass of pink egg capsules. Each capsule contains a number of developing cowry larvae.

Undisturbed specimens at night may extend their pointed and slightly branched papillae way out, as in the specimen below from Hawaii.

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The purple color, particularly that of the base, tends to fade over time in empty shells. The first empty shell below measures 19.2mm and was found in March, 1972.

18.0mm, 5 March 2001

10.6mm, 14 March 2016

10.15mm, March 1972

28.6mm shell, April 1973. The large specimen below was found while cleaning out the inside of a large pipe carrying sea water used to cool power plant generators.

Comparison of 28.6 and 10.15mm shells.

Created 1 April 2008
Updated 3 April 2024

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