About 2 dozen species of limpets live on the west coast.   Keyhole limpets are not really closely related to limpets, but are included here for convenience.  There is also a small section on marine pulmonates, also not related to limpets, but resembling limpets in shape and behaviour. The photo series below may be handy for identification of 4 common west-coast species. Photographs courtesy Linda Schroeder, Pacific Northwest Shell Club, Seattle PNWSC.

NOTE  the word “limpet” originates from the Old English “lempedu”, itself derived from a similar Latin word, referring to the animal itself.  There have been several major revisions to west-coast limpet taxonomy over the past several decades.  At one time (e.g., Ricketts & Calvin 1939-1968 Between Pacific Tides Stanford Univ Press, Stanford), most species were classified in genus Acmaea (an exception being the owl limpet Lottia gigantea).  Several later revisions to the classification (e.g., Lindberg 1981 Acmaeidae Gastropoda MOLLUSCA The Boxwood Press, Pacific Grove, California; Lindberg 1986 Veliger 29: 142) treated west-coast biologists to a re-sorting of the species every few years into a number of genera including Acmaea, Lottia, Notoacmea, Tectura, Macclintockia, Discurria, and Collisella. With the advent of modern molecular techniques, recent re-classification has placed all west-coast Patellogastropoda (formerly known as Archaeogastropoda) in the genus Lottia, although the positioning is by no means certain.  The classification used here follows that of Lindberg 2007 p. 753 In, The Light and Smith Manual Intertidal invertebrates from central California to Oregon (Carlton, ed.) Univ Calif Press, Berkeley. Simison & Lindberg 2003 Veliger 46: 1 have also clarified through molecular-sequencing data that Lottia strigatella and L. paradigitalis, long thought to be the same species are, in fact, separate species. The former is a southern California/Baja California resident, while the latter is distributed from the Aleutian Islands, Alaska to southern California.

  photographs of 4 species of limpets Lottia that are hard to identify in a beach setting, courtesy Linda Schroeder, PNWSC
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ANIMATION of snail meeting LIMPET
© 2010 Thomas Carefoot

To learn about west-coast LIMPETS & RELATIVES: select a topic from the limpet menu at the top of the page

OR: play the ANIMATION of the snail meeting the LIMPET

OR, if you want to see other animations: follow the snail on its ODYSSEY by CLICKING on any X-marked invertebrate on the map

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Phylum Mollusca (lit. “soft” or “shellfish” L.)

Class Gastropoda (lit. “stomach foot” G.), referring to the body structure of viscera lying overtop of the muscular foot

SubClass/Clade Eogastropoda (lit. “early gastropod” G.)

SuperOrder/Clade Patellogastropoda (lit. “like a little dish” L. + gastropod), including limpets

Family Acmaeidae (lit. “point” or “highest point” G.), including dunce-cap limpets Acmaea mitra

Family Lottidae, including all other limpets, Lottia spp.

SubClass/Clade Orthogastropoda (lit. “straight gastropod” G.) referring not to the shell but to aspects of their phylogeny

SuperOrder/Clade Vetigastropoda

Family Fissurellidae (lit. “cleft” L.), including keyhole limpets Diodora aspera

SubClass/Clade Heterobranchia/Clade

Family Trimusculidae (lit. “three muscle” L.), including marine pulmonates Trimusculus reticulatus

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