Lottia asmi (Middendorf, 1847)

Common name(s): Black limpet

Synonyms: Acmaea asmi, Collisella asmi Lottia asmi
Phylum Mollusca 
Class Gastropoda 
Subclass Prosobranchia 
Order Patellograstropoda 
Suborder Nacellina 
Family Lottidae 
Lottia asmi (on right), about 0.5 cm long, on a Chlorostoma funebralis snail shell.  At San Simeon Beach, CA
(Photo by:  Dave Cowles, August 2010)

Description:  This limpet has a moderately high apex about 1/3 from the front of the shell.  The outside is grayish or brownish black without major ribs, often partly eroded, while the inside is black.  Sometimes a light band is found inside the shell running around the aperture near the margin.  The external shell is mostly smooth but fine radial ridges can sometimes be seen at the margin.  Usually found living on the black turban snail Chlorostoma funebralis but sometimes on Mytilus californianus.  Length up to about 1cm and height to 8 mm.

How to Distinguish from Similar Species: Most other dark, smooth limpets grow larger and do not usually live on black turban snails (at least as adults--some juveniles of other species may be found on turban snails but their shells are generally flatter--see the photo above).

Geographical Range: Southern Alaska to Islas de Revillagigedo, northern Mexico

Depth Range: Mostly intertidal

Habitat: Usually found on the black turban snail Chlorostoma funebralis

Biology/Natural History:  As with other limpets, this species grazes on microalgae on the substrate (in this case, on the turban snail's shell).  The species may move from one host to another, probably when the hosts are aggregated together at low tide.  It avoids shells that are not occupied, and seems to prefer shells occupied by snails to those occupied by hermit crabs.  Washing shells with alcohol or distilled water reduce the limpet's attraction to them.

Spawning is in spring and fall.  Eggs and sperm are released into the water.  Larvae have a planktonic phase and develop a coiled shell before settling and developing a cap-shaped shell.

In California this limpet sometimes is found on the shell of the speckled turban, Tegula gallinea.



Dichotomous Keys:
  Carlton, 2007
  Flora and Fairbanks, 1966 (as Collisella asmi)
  Kozloff, 1987, 1996

General References:
  Brandon and Rokop, 1985 (as Collisella asmi)
  Hinton, 1987 (as Collisella asmi)
  Johnson and Snook, 1955 (as Acmaea asmi)
  Kozloff, 1993 (as Collisella asmi)
  Lamb and Hanby, 2005
  Morris et al., 1980 (as Collisella asmi)
  Niesen, 1997
  Rice, 1973
  Ricketts et al., 1985 (as Collisella asmi)

Scientific Articles:
Alleman, L. L., 1968.  Factors affecting the attraction of Acmaea asmi to Tegula funebralis.  Veliger 11 (supplement): pp 61-63

Brewer, B.A., 1975.  Epizoic limpets on the black turban snail, Tegula funebralis (A. Adams, 1855).  Veliger 17: pp 307-310

Eikenberry, A.B. Jr. and D. E. Wickizer, 1964.  Studies on the commensal limpet Acmaea asmi in relation to its host, Tegula funebralis.  Veliger 6 (supplement): pp 66-70

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

Authors and Editors of Page:
Dave Cowles (2010):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Rosario Invertebrates web site provided courtesy of Walla Walla University