Limpet
Limpets eat by grazing on algae found on rock surfaces. They scrape films of algae from the rock with a radula, a ribbon-like tongue with rows of teeth. Limpets move by rippling the muscles of their foot in a wave-like motion. Most limpets are less than 3in (8cm) long, but a West Mexican Limpet grows to be 8in (20 cm).