Haustrum haustorium

Haustrum haustorium
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Orthogastropoda
Superorder:	Caenogastropoda
Order:	Sorbeoconcha
Suborder:	Hypsogastropoda
Infraorder:	Neogastropoda
Superfamily:	Muricoidea
Family:	Muricidae
Subfamily:	Haustrinae
Genus:	Haustrum Perry, 1811
Species:	H. haustorium
Binomial name
Haustrum haustorium (Gmelin, 1791)

Haustrum haustorium, or the dark rock shell, is a gastropod mollusc of the family Muricidae, the only species in the genus Haustrum. It is endemic to New Zealand, and found in the lower intertidal zone.

The shell is rather large and solid ewith a low conical spire, and a rapidly expanding body whorl that tapers gradually to the anterior end. The aperture is large, and the outer lip is thin and crenulated. The inner lip has a broad smooth excavated callus. Sculpture is coarse uneven spiral ridges, separated by linear grooves. The operculum is ovate-lunate.

Coloration of the exterior is dull purplish-brown, with the aperture and parietal callus white except for a splash of reddish-brown within, and a border of purplish-brown streaks inside the outer lip.

Haustrum haustorium's food is other gastropods, including the oyster borer. Access is gained by drilling through the prey's shell with its radula.

The height is up to 65 mm, and the width 45 mm.

References

• Powell A W B, New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
• Glen Pownall, New Zealand Shells and Shellfish, Seven Seas Publishing Pty Ltd, Wellington, New Zealand 1979 ISBN 85467 054 8
• Miller M & Batt G, Reef and Beach Life of New Zealand, William Collins (New Zealand) Ltd, Auckland, New Zealand 1973