The Tall-ribbed Limpet has a southern Australian temperate distribution pattern. Its range includes from northern NSW, around the southern coastline, including Vic, Tas and SA, up to Geraldton, WA. (NSW, VIC, TAS, SA, WA)Features:
The Tall-ribbed Limpet is a distinctive, solid, cone-shaped limpet that has between 12-30 (usually 18) strong, partly scaled, radial ribs that go beyond the edge of the shell to create a strongly notched or scalloped shell margin. The ribs are more close together at the rear. It grows to a length of 25 - 40mm, a width of 37 mm and a height of 15 mm. The shell apex is just in front of the shell's centre. It is less tall than the Scaly Limpet, Patella peronii, which usually has 24 ribs. The shell is often eroded, sometimes making identification difficult.
The shell is dull white to grey-green in colour, with rows of distinctive, fine, crescent shaped, brown to black marks running down the rib spaces to form a cobweb-like pattern. The outer surface is often tinged green caused by fine algal growths on the shell surface. Inside a dead shell, the surface is a white porcellaneous colour and not iridescent, while the spatula is brown coloured. The inside shell margin is light brown, with the exterior black pattern showing through the shell's rib indentations. The animal is dull yellow, merging to brown in colour. Its gill plume lies over the head and under the mantle.Ecology/Way of Life:
The Tall-ribbed Limpet occurs at and below low tide levels on exposed rocky coasts. It feeds on algae and often shelters among red coralline seaweeds. Like the Variegated Limpet, Cellana tramoserica, the Tall-ribbed Limpet shows home-returning behaviour. Predators of this species include the Cart-rut Shell, Thais orbita, and various species of fish, including the wrasse, Pseudolabrus fucicola in Vic. The north-eastern form of this species is sufficiently different so that it is considered to be a sub-species, Patelloida alticostata antellia. A form that lives below low tide level is more flat and smooth and is named Patelloida alticostata complanata. In southern areas this limpet is found higher on the shore than its more northerly brethren. Large animals may be five years old. Studies have been carried out on the reproductive biology and population dynamics of this species (Black 1977, Fletcher 1987). After spawning, the lecithotrophic (non-feeding) larvae spend about six days in the water before settling (Anderson 1965).Interaction with Humans/Threats:
This shell appears to be quite common across its range, especially along southern Australian shores and seems not to be under threat from human activities.Other Comments:
Patelloida alticostata, Angas, 1865. Patelloida comes from the Latin word patena or patina, meaning a plate. Alticostata comes from two Latin words; alti comes from altus, meaning high, and costata comes from costa, meaning a rib. This describes a limpet shaped like a dinner plate with tall ribs.Further Reading:
Anderson, D.T. (1965). The reproduction and early life histories of the gastropods Notoacmaea petterdi (Ten.-Woods), Chiazacmaea flammea (Quoy and Gaimard) and Patelloida alticostata (Angas) (Fam. Acmaeidae). Proc. Linn. Soc. N.S.W. 90, 106-114.
Bennett, I. (1987). W. J. Dakin's classic study: Australian Seashores: a guide to the temperate shores for the beach-lover, the naturalist, the shore-fisherman and the student. p.270, Angus and Robertson.
Black, R. (1977). Population regulation in the intertidal limpet Patelloida alticostata (Angas, 1865) Oecologia 30, 9-22.
Davey, K. (1998). A Photographic Guide to Seashore Life of Australia. p.81, New Holland Press, Sydney.
Edgar, G. J. (1997). Australian Marine Life: the plants and animals of temperate waters. p.234, Reed.
Fletcher, W. J. (1987). Life history dynamics of the limpet Patelloida alticostata in intertidal and subtidal environments. Marine Ecology - Progress Series 39:115-127.
Jansen, P. (2000). Seashells of South-East Australia. p.10, Capricornia Publications.
Jones, D. and Morgan, G. (1994). A Field Guide to Crustaceans of Australian waters.
Macpherson, J. H. and Gabriel, C. J. (1962). Marine Molluscs of Victoria. p.48, Melbourne University Press.
Marine Research Group of Victoria (1984). Coastal Invertebrates of Victoria: An atlas of selected species.p.30, Museum of Victoria.
Shepherd, S. A. and Thomas, I. M. (1989). Marine Invertebrates of Southern Australia. Pt. II. p.544, South Australian Govt. Printing.
Wells, F. E. and Bryce, C. W. (1988). Seashells of Western Australia. p.38, Western Australian Museum.
Wilson, B. (1993). Australian Marine Shells. Prosobranch gastropods. Odyssey Publishing.
Wilson, B. R. and Gillett, K. (1979). A Field Guide to Australian Shells: Prosobranch Gastropods. p.32, Reed.
Text, map and photograph by Keith Davey.Sponsorship welcomed:
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