Limpets
Several species of limpets are found on Sydney's rocky shores.
Identification
Limpets have a tent-shaped shell that is almost impossible to dislodge from rocks.
Habitat
Limpets are found on intertidal rocky shores.
Distribution
Limpets are found in the temperate waters of southern Australia, including southern Queensland, New South Wales, Victoria and South Australia to Western Australia.
Feeding and diet
Limpets are often found in dense groups on intertidal rock platforms feeding on algae.
Other behaviours and adaptations
To avoid drying out, limpets scour a 'home base' with their shell edge and trap a bubble of water underneath. They may travel more than 1 m from their home base, scraping algae off the rocks during high tide before returning at low tide. Interestingly, they always return to the same position each time, retracing the scent of their mucous trail.
Limpets play an important role in rock-platform ecology, as many intertidal species have free-swimming larvae that need bare rock on which to settle and mature. A reduction in the number of limpets would lead to an increase in the amount of algae on the rocks, which would affect the abundance of other rock-platform animals.