Nucella lamellosa (Gmelin 1791) Common name: Frilled dogwinkle, Wrinkled purple
Synonyms: Thais lamellosa
Phylum Mollusca  Class Gastropoda    Order Neogastropoda     Suborder Rachiglossa      Family Nucellidae
	Nucella lamellosa from Northwest island, at Rosario Bay
	(Photo by: Nathaniel Charbonneau 7/26/02)

How to Distinguish from Similar Species:  Other local Nucella typically have no frilly axial lamellae (but see note below) and rarely exceed 3 cm in length. Nucella ostrina may sometimes look very similar but it has alternating large and small spiral ridges and the siphonal canal is less than 1/4 as long as the aperture. N. canaliculata has many spiral ridges of similar size with deep grooves between..

Linda Schroeder has added this helpful information for distinguishing N. lamellosa from N. ostrina based on the axial lamellae: :  "N. ostrina can definitely have axial lamellae, but less common to see than on N. lamellosa.  The lamellae are much closer together (in N. ostrina, photo) than on N. lamellosa (photo) and also don't protrude as much."

This table lists some other general distinctions between N. lamellosa and N. ostrina:, based on information from the Oregon Institute of Marine Biology:
Nucella lamellosa	Nucella ostrina
Habitat: Quiet water or wave action, intertidal or subtidal	Areas of wave action, intertidal
Shell length (height): To 5 cm or more	Usually < 2 cm, rarely > 3
Shell thickness: Heavy, solid	Not heavy
Number of whorls: 5-7	3-4
Outside sculpture:  Variable:  Lamellar form (quiet water): Strong spiral ridges, frilly axial lamellae (photo) Rough waters: Flattened, angled whorls which are smooth or have 1-2 strong spiral ridges near top of each whorl (photo); or ridges may be worn off (photo)	No axial sculpture, or small, close-spaced axial ruffles. Spiral sculpture of multiple alternating large and small ridges which may be obscure or nodulose
Sutures: Not deep	Not deep
Aperture length: Nearly 1/2 shell length	More than 1/2 shell length
Aperture inside color: Whitish	Brown or purple (or orange)
Aperture outer lip: Thick and smooth, with an inner row of several denticles deep within the aperture	Thinner, often crenulate outer lip with no denticles
Siphonal canal: Longer than 1/4 aperture length, not closed	Shorter than 1/4 aperture length, not closed

Geographical Range:  Nucella lamellosa is found from the Bering Strait to central California.

Depth Range:  Low intertidal to mid intertidal

Habitat: Rocky substrate, commonly found on mussel beds

Biology/Natural History:  A most peculiar species because of its ability to vary so much in shape, color, and texture from one individual to the next. This sometimes makes it hard to key out with confidence. It is one of the most common intertidal whelks in the Pacific Northwest. Nucella lamellosa is a carnivore, feeding especially on acorn barnacles (photo) and mussels. After locating its prey the whelk uses its radula to scrape through the shell and eat out the soft flesh inside.  Predators include the red cancer crab Cancer productus and the seastar Pisaster ochraceus. Prolonged exposure to chemical cues from C. productus, which cracks the snail's shell during predation, induced growth of a more rotund shell with thicker walls. Prolonged exposure to chemical cues from P. ochraceus, which reaches into the shell, induced growth of  elongated shells with higher spires which allowed the snail to further retreat into the shell. These cues also stimulated the snails to seek shelter more consistently (Bordeau, 2009)

While this species is often found in somewhat brackish water of bays and estuaries, Covernton and Harley (2020) found that the population near the mouth of the Fraser River, Canada found that population size decreased after major freshwater exposures from the river. Laboratory studies found developmental delay in encapsulated embryos at lower salinity, and complete mortality at 9-12 psu. Juveniles (< 30 mm shell length) also experienced more mortality at low salinities than adults did unless they were periodically also exposed to salinities at least 20 psu.

This snail may be found congregating in large groups to breed in the spring and summer (photo).  Their eggs are in oatlike capsules which are attached by stalks to the rocks (photo)

In his dissertation, Seavey (1977) reports that on the Oregon coast it takes approximately 20 months for eggs to mature in this specie. Spermatogenesis occurs throughout the year. in males. Spawning begins in June in Yaquina Bay, Oregon. 

In the study by Sorte and Hofmann (2005), thermotolerance of different Nucella species along the coast was found to be correlated with the latitude range and tidal height each species occupies.  N. ostrina, which occurs higher in the intertidal than does N. canaliculata in Oregon and does not extend as far north, had higher heat tolerance than did N. canaliculata. N. emarginata, which extends the farthest south, and N. ostrina, which lives higher in the intertidal, recovered more quickly from thermal exposure than did N. canaliculata and N. lamellosa, which live lower in the intertidal, and N. lima, which has a more northern range.  These differences in heat tolerance may be related to HSP70 molecular chaperones.

The famous Tyrian purple dye from the city of Tyre, that colored royal Roman robes, was made from a relative of Nucella.  The snails were ground up in a stone mortar and processed by a method that has been partly lost to get the dye. Different combinations made different shades of purple.  The dye should be fixed with lemon juice as a mordant.  The American species produce a much less brilliant purple than do the Mediterranean species.

Dichotomous Keys:
  Carlton, 2007
  Kozloff, 1987

General References:
  Harbo, 2011
  Kozloff, 1993
  Lamb and Hanby, 2005
  Morris, Abbott, and Haderlie, 1992

   A 2023 online BBC article about making Tyrian purple dye

Scientific Articles:

Bordeau, Paul E., 2009. Prioritized phenotypic responses to combined predators in a marine snail. Ecology 90:6 pp 1659-1669

Covernton and Harley, 2020. Multi-scale variation in salinity: a driver of population size and structure in the muricid gastropod Nucella lamellosa. Marine Ecology Progress Series 643: pp. 1-19

Rawlings, 1999. Adaptations to physical stresses in the intertidal zone: the egg capsules of neogastropod molluscs. American Zoologist 39:2 pp. 230-243

Seavy, Donald K., 1977. Seasonal gametogenesis and egg laying in the prosobranch gastropods Nucella lamellosa, Nucella emarginata, Searlesia dira, and Amphissa columbiana on the Oregon coast. Ph.D. dissertation, Oregon State University. 179 pp.

Sorte, Cascade J.B. and Gretchen E. Hofmann, 2005.  Thermotolerance and heat-shock protein expression in northeastern Pacific Nucella species with different biogeographical ranges.  Marine Biology 146: 985-993

This larger individual has some frilly axial lamellae growing from the body whorl.  Photo by Dave Cowles, July 2005
 

Here is another frilled individual (with axial lamellae).  Photo by Dave Cowles, July 2009
 

In this photo a worn Nucella lamellosa (as is often seen in the intertidal) is eating a Semibalanus cariosus barnacle in the intertidal

During the mating season, large aggregations of N. lamellosa can often be found among the rocks.  Often egg clusters can be found attached to the rocks nearby (see below)
Photo at Kalaloch Beach #4 by Dave Cowles, July 2009

Here is a cluster of N. lamellosa eggs hanging under a rock.  Photo by Dave Cowles at Kalaloch Beach #4, July 2009
 

This aggregation of egglaying Nucella lamellosa was under a boulder on Sares Head, April 2011.  Photo by David Cowles
 

This multicolored individual, about 6 cm long, was photographed at Cape Flattery. Photo by Dave Cowles
 

Here is an unusual purple individual (live) collected in summer 2006.  The shell is about 2 cm long. 

More color variation.  These individuals are from a rock at Beach #4, Kalaloch July 2008.  Photo by Dave Cowles

And yet more variation. This individual, at the Coupeville (Whidbey Island) ferry landing, is nicely banded with orange. Photo by Dave Cowles, 2011 

In July 2005, Jon Mayberry, Matt Henderson, and Taylor Wilkins did a student project titled "Tidal effect on daily migration patterns in Nucella lamellosa".  In the study they followed vertical movements of N. lamellosa through six height zones in an aquarium during changes in water depth that simulated the ambient tidal cycle, and in a control tank that always remained full.  They found that the snails in the control (full) tank continued to move all the time while snails in the tidal tank stopped moving almost entirely during low tide except for a few that fell to the bottom of the tank, making a highly significant difference in movement between the tidal and nontidal tanks at low tide.  The average height of the snails differed both at high and at low tide, with snails in the tidal tank higher.  This may have been due to the fact that at low tide the snails in the tidal tank "froze" in position.  They also observed what might have been a migration downward at nightfall in both tanks.  The figure below (figure 3 from their data) summarizes their results.  Zone 0 was at the bottom of the tank, zone 6 on top.