Marine Life

Giant Keyhole Limpet
(Megthura crenulata)
Courtesy of Tom Haight

This odd-looking gastropod carries its shell under its skin. Growing to a length of 5 inches and coming in a variety of colors this snail is very common in Southern California. The "keyhole" is actually used for water that passes over the gills to exit the body. Some of the coastal Indians used the shells for money and for decorations in little girls hair. It feeds on algae which it scrapes off with it's radula (a file-like tongue). Although the Giant Keyhole Limpet is not eaten much in this country as yet, it is a favorite food in Japan.