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Owl Limpet (Lottia gigantea) - : It is most abundant in California and favors vertical rock faces in wave-swept areas in the upper littoral zone. It grows slowly and may live for up to 20 years. It browses on microalgae growing on rock surfaces. The owl limpet is a territorial species and some individuals return to the same specific location every time the tide goes out. The limpet's contours grow to fit the rock surface tightly. Large female limpets graze on the film of algae growing on rocks and defend their territory against other owl limpets, mobile gastropods, mussels, sea anemones, barnacles and macroalgae. They dislodge large competitors by pushing them away with the anterior part of the shell, and if barnacles settle, they are rasped away with the radula.