Giant Keyhole Limpet
- Slimy gray, black, or brown covering a gray oblong, oval shell
- A black central hole at the top of the shell, the portal through which waste products are released
- Sessile, attached to rocks
- Monterey, California to Baja California, Mexico
- Intertidal zone
- Depths up to 108 feet
- Filamentous cyanobacteria, diatoms, brown and red algae such as seaweed, seagrass, forams, hydrozoans, bryozoans, nematodes, bivalves, gastropods, crustaceans, and tunicates
- People use this species for medicinal uses
- The primary predators for limpets are sea stars, birds, and the occasional crab
- This species is one of the largest keyhole limpets.
- The whole on the top of the shell makes them different from true limpets, which release waste from the mantle beneath the shell.
- The blood of this species is used in many cancer treatments and vaccines, as it stimulates the immune system and its protein transports molecules throughout the body.
- A liter of blood from a keyhole limpet will produce 20 grams of protein, which can be worth as much as $100,000.
- Their shells were used as currency among Native Americans
Sources: Harris and Markl, 1999; Harvesting blood from limpets for a cancer vaccine; How mollusk blood could cure cancer; Marine Biology. 8th ed.; Encyclopedia of Life; CaliforniaTidePools.com
Photo: Frederic Pache