Fissurella maxima

Fissurella maxima, common name the giant keyhole limpet, is a species of sea snail. It is a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets.

Description

The size of an adult shell can be as small as 50 millimeters, but is usually above 65 mm. The largest specimens are about 138 millimeters. No size-based sexual dimorphism has been found.

F. maxima occurs in the Pacific Ocean between Ecuador and Tierra del Fuego. It is most commonly recorded in areas with a sea surface temperature of 10–15 °C. It lives in the intertidal zone, usually on algae or the undersides of flat rocks.

F. maxima is dioecious, with separate male and female sexes. They primarily spawn during late November to December, but also have a secondary peak during July and August.