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.

When the tide goes out leaving the limpet out of the water, it pulls itself down so that it fits completely inside its shell and grabs onto the rocks, waiting for the tide to come back up.

Megathura_crenulata