Auger-shaped Screw Shell
The Auger-shaped Screw Shell has an Indo-West Pacific distribution. In Australia it ranges from North West Cape, Western Australia, across northern shores including NT, to central Qld (WA, NT, QLD).
The Auger-shaped Screw Shell has a solid, long, auger-shaped shell with 20-25 strongly convex whorls. The suture is very prominent. It grows to a length of 170-180 mm. Its base is rounded and convex (outward curving). The body whorls are strongly sculptured with spiral ribs or keels. It lacks an anterior canal notch, so the aperture is entire and almost circular. This feature distinguishes it from the similar terrebrids. Its large operculum is composed of horn-like material.
The smaller whorls are coloured fawn or cream, grading to brown on the larger whorls.
Ecology/Way of Life:
The Auger-shaped Screw Shell normally occurs sub-tidally, but extends into the tidal zone. It prefers soft substrates, usually mud. It feeds by gathering fine particles of organic detritus trapped in the mucous sheets on the gills. This material is then sucked into the mantle cavity by ciliary water currents.
Interaction with Humans/Threats:
The Auger-shaped Screw Shell has a wide tropical distribution and does not appear to be under threat from human activities.
Turritella terebra, Linnaeus, 1758. Both Turitella cerea and T. spectrum, Reeve, 1949, are synonyms.
Turritella comes from the Latin word turris meaning a tower, while terebra is the Latin name for their engine for boring walls, and describes this species auger-like shape of the shell.
Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. New Holland Press, p.105, Sydney.
Garrard, T. A. (1972) J. Malac. Soc. Aust. 2(3), 267-338.
Wilson, B. (1993) Australian Marine Shells. v.I . p.140.
Wilson, B. R. & Gillett, K. (1979). A Field Guide to Australian Shells: Prosobranch Gastropods. p.54, Reed.
Text, map & photograph by Keith Davey.
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