The eggs are laid in pink jelly-like masses under rocks and the young winkles crawl out. This flat species lacks a spire and is found amongst the fronds of the Serrated Wrack and the Bladder Wrack which occupy distinctive zones in the middle to upper shore on rocky shores. Dark green and yellow specimens are common. Edible Periwinkle Found in millions where left unexploited by man. Usually black or bleached grey by the sun, there are also striped and coloured specimens.
Winkles are herbivorous and graze on algae on rocks.
In aquaria their feeding trails can be observed. They are resistant to desiccation at low tide, and possess a thin transparent operculum to seal off the aperture. They should not be confused with the topshells, which are superficially similar and common on the lower shore. The most widespread species is the Grey or Silver Top, Gibbula cineraria .