Diodora cayenensis - Cayenne Keyhole Limpet
Habitat The Cayenne Keyhole Limpet is typically found living in intertidal zones, but they can be found in depths of up to 100 feet. Living limpets are often attached to rocks or other hard substrates, and shells can be found on sandy beaches.
Range Can be found in inlets and offshore waters in Maryland all the way to down to Florida and the Gulf coast as well as in the West Indies and down to Brazil.
Description The Cayenne Keyhole Limpet is a member of the family Fissurellidae, which are conically-shaped shells in temperate and tropical seas. The gastropod's surface is radially ribbed, and every fourth rib is larger. At the apex of the shell, there is a keyhole-shaped slit, which is how the shell gets its name, and the shells typically do not exceed 2 inches in diameter. Most have a white, gray, tan, or pink color to them with an interior of white or blue-gray.
Ecological Notes This gastropod is an herbivore that feeds by using a radula to scrape algae off of rocks. Due to this scraping on rocks wearing down its teeth and radula, new teeth are constantly being formed by the limpet. For locomotion to find this algae, the limpet has a large, fleshy foot that allows it to move around slowly on the rocks. The foot also has strong suction to hold the gastropod on rocks and keep it from being washed away by waves.
The Cayenne Keyhole Limpet brings in water from under the edge of the shell for respiration and excretion, and it exits through the keyhole at the apex of the shell.
Eggs of this species are yellow and stick to rocks. The juveniles crawl away when hatched.
Personal Information I came across a couple of Cayenne Keyhole Limpets on the beach in front of the Cape Hatteras lighthouse in North Carolina.
Kantele, A. M., Häkkinen, M., Zivny, J., Elson, C. O., Mestecky, J., & Kantele, J. 2011. Humoral immune response to keyhole limpet haemocyanin, the protein carrier in cancer vaccines. Clinical and Developmental Immunology. Reference info needed.
This article studied the effects of using keyhole limpet haemocyanin as a protein carrier for tumor antigens in cancer vaccine candidates. The authors specifically looked at the expressions of homing receptors to reveal where the immune response was being targeted in the body.
Voltzow, J. (2015), Endoscopy of gastropods: A novel view of the mantle cavities and gills of the keyhole limpet Diodora aspera and the abalone Haliotis rufescens. Journal of Morphology, 276: 787–796. doi:10.1002/jmor.20379
The author of this paper focused on describing the mantle cavity of different gastropods through the use of endoscopy. She specifically compared the gills and their responses to disturbances in the water in gastropods with openings in their shells such as the keyhole limpet and abalone.
Contributed by Cortney Kourie - 2016