Australian Biological Resources Study

Species Bank Home

Onchidella patelloides (Family Onchidiidae)

Limpet-like Onchidella


The Limpet-like Onchidella ranges from NSW, Vic to northern Tas (NSW, VIC, TAS). It also occurs in New Zealand.


The Limpet-like Onchidella is a small, oval, slug-like air-breathing pulmonate, with a tall and thick leathery mantle covered with very small granules and scattered, large bumps, called papillae. Generally it has a clean surface and does not have tufts or radiating growths like other sea-slugs. Its mantle border is scalloped or notched. It grows to 25 mm in length.

The Limpet-like Onchidella has no shell. Its head is small, with short, conical tentacles and small eyes. The animal is coloured green or yellowish-brown, with darker or lighter markings radiating from the top to the margin where there are whitish marginal glands. These bars give this pulmonate a limpet-like appearance, hence its scientific name.

Ecology/Way of Life:

The Limpet-like Onchidella may be locally abundant and occurs at mid-tide level and below, usually under stones, or under protective rock overhangs on moderately exposed shores. It is often associated with Galeolaria encrustations and mussel beds where it may be extremely common. It is active nocturnally and is also frequently found on overcast days.

Interaction with Humans/Threats:

The Limpet-like Onchidella is common across its range and is therefore most likely not under threat from human activities.

Further Reading:

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.308, Angus & Robertson.

Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. p.119, New Holland Press, Sydney.

Edgar, G.J. (1997). Australian Marine Life: the plants and animals of temperate waters. p.269, Reed.

Macpherson, J. H. & Gabriel, C. J. (1962). Marine Molluscs of Victoria. p.264, Melbourne University Press.

Marine Research Group of Victoria (1984). Coastal Invertebrates of Victoria: An atlas of selected species.p.75, Museum of Victoria.


Text, map & photograph by Keith Davey.

Sponsorship welcomed:

Please Contact ABRS if you wish to discuss sponsoring this or other pages.


Distribution Map

Attached Images

Return to Species Bank home



   Links to another web site
   Opens a pop-up window