Univalve Shellfish

Imagine living with your stomach in your foot!

Paua      Shield shell      Limpets      Whelks     Tiger shell

Univalves are shellfish with only one valve or shell. They are a part of the largest group of shellfish and are termed gastropod or stomach-foot.

Paua and Pink Pauapaua

Other Names: Related to the American Abalone and Channel Islands Ormer. Both known as Sea Ear or orielle de mer. They belong to the family Haliotidae which comes from the Greek hals - sea, and otos - ear. (Haliotis iris)

Habitat: Young paua live under stones near low-water mark, however older paua migrate towards deeper water.

Identification: Has a large shell coiled in a flat spiral, the foot protruding beneath the edge of the shell. It has a row of holes near the shell edge, with a smooth surface between the holes and the edge of the shell. The pink paua is smaller and has an overall pinkish colour with three or more strong spiral ridges between the row of holes and the shell edge.

General: Commonly taken for eating the large fleshy foot, or for use of the shell in making mother-of-pearl type ornaments. Three species live in New Zealand and similar species occur in Australia, Japan, California and Europe.


Shield Shell

(Scutus antipodes)

Habitat: On stones below the low-water mark.

Identification: A large, velvety-black animal which is sometimes mistaken for a paua which has lost its shell.

General: The flesh of the animal almost completely covers its small solid shell which is shaped like a roman soldier's shield. If you gently stroke the back of a shield shell, the outer layer of flesh opens up and exposes the shell.



Other Names: Ornate, radiate, fragile and ribbed slipper limpets. (Cellana sp.)

Habitat: Limpets occur on most rocky coasts and generally live up near the mid or high-tide line.

Identification: Variable in shape, size and colour, but readily spotted clinging to rocks. The two commonest species are the ornate and radiate limpets.

General: Limpets feed on seaweed and only become active when covered by the tide.



Other Names: Knobbed, spotted, speckled and lined whelks. (Cominella sp.)

Habitat: Range from sandy beaches to harbour mud flats. Speckled and lined whelks also live on rocky coasts. Lives from shallow water to about 180 m.

Identification: This marine gastropod is also called the sea snail. Shells are spiral in shape.

General: Whelks are active and carnivorous, living on live or dead animals which they grasp with their foot. They bore holes with their toothed mouths into the shells of other molluscs, their prey.


Tiger Shelltiger

(Calliostoma tigris)

Habitat: Rocky coastlines and on large brown seaweeds.

Identification: Can grow to 10 cm, have a distinctive tiger stripe or flecked pattern on their spiral shape.

General: One of the shells most prized by collectors because of its distinctive colouring. The one in the picture was on a large slaty sponge.


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