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Ribbed Top Shell Austrocochlea constricta

Form:photo of Ribbed Top Shell

The Ribbed Top Shell has a shell which is thick, rounded, and cone shaped with a sharp apex.

It has rounded whorls, with a sculpture of 5-6 strong, spiral ribs.

The shell height is equal to its width.

The shell aperture is rounded and ridged.

The columella is short, with single tooth. The covering operculum is horny and rounded.

Click on the underlined words to see the words defined in the Glossary.
Click here to see an illustration which also explains these technical terms.


The colour of the Ribbed Top Shell is a uniform dull grey to off-white.




Lamarck, 1822




25 -50 mm diameter


distribution map of Ribbed Top ShellThe Ribbed Top Shell ranges from Coffs Harbour, in northern New South Wales, around southern shores to Albany, southern Western Australia.


It is abundant at mid tide levels on exposed rock surfaces on medium to low-energy coasts. This very common mollusc is found in a variety of habitats.


The Ribbed Top Shell feeds by scraping algae from the rock surface. It leaves distinctive trails in loose sand in rock pools.

For many years this Top Shell was clumped together with the Zebra Top Shell, A. porcata, which is more common along the New South Wales coast. Recently, the two forms have been considered to be separate species.

The Ribbed Top Shell is eaten by the predatory molluscs, the Cart Rut Shell, Dicathais orbita and the Wine-mouthed Lepsiella, Lepsiella vinosa, a southern species.


Bennett, I. (1987) W. J. Dakin's classic study: Australian Seashores. p,242, Angus & Robertson, Sydney.

Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. p.88, New Holland, Sydney.

Edgar, G. J. (1997) Australian Marine Life: the plants and animals of temperate waters. p.240, Reed Books, Kew.

Quinn, G. P., Wescott, G. C. & Synnot, R. N. (1992) Life on the Rocky Shores of South-Eastern Australia: an illustrated field guide. p.42, Victorian National Parks Association, Melbourne.

Marine Research Group of Victoria (1984) Coastal Invertebrates of Victoria: an atlas of selected species. p. 38, Museum of Victoria, Melbourne.

Macpherson, J. H. & Gabriel, C. J. (1962) Marine Molluscs of Victoria. p.69, Melbourne University Press & The National Museum of Victoria.

Shepherd, S. A. & Thomas, I. M. (1982) Marine Invertebrates of Victoria, Pt. 2. p. 553, South Australian Government Printer, Adelaide.

Underwood, A. J. & Chapman, M. G. (1993) Seashores: a beachcomber's guide. p.30, New South Wales University Press, Sydney.

Wilson, B. R. & Gillett, K. (1979) A field guide to Australian Shells: Prosobranch Gastropods. p. 36, A. H. & A. W. Reed, Sydney.

Top Shells & Relatives

Zebra Top Shell
Ribbed Top Shell
Wavy Top Shell

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photo of Keith DaveyLife on Australian Seashores
by Keith Davey (C) 2000

Learning Consultant - Media
The University of Newcastle

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Scientific Consultant: Phil Colman
site created 01.01.98 : updated 01.04.2000