Ocinebrina lurida : Lurid rock snail. The orange snail on the left is probably Ocenebrina. The others are various litorine snails.

Physical description:
Small,size to 1 1/2 ” (38 mm) solid shell with up to 6 whorls; fine close spiral treads crossing 6-10 axial ribs; Oval aperture with 6-7 teeth or more within outer lip height. Shell height most commonly is up to 40 mm, however usually less, with six to ten large low axial ridges crossed by prominent spiral ridges. Colors range from white, pale yellowish, dark brown, or red. It has a canal well developed, and its aperture is oval.
Classification
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Sub class Prosobranchia
Order Neogastropoda
Family Muricidae
Genus Ocinebrina
Species lurida
Common Name: lurid rock snail

Global Distribution

Ranges from Sitka (Alaska) to Punta Santo Tomas
(Baja California). 57° N- 32° N, in the Pacific Ocean.

Habitat
Low intertidal zones, visible amongst the fucus and other algae at low tide.It is common on and under rocks and in crevices, commonly, clinging to rocks.

Feeding
The lurid rock snail is the natural predator of the giant chiton, Cryptochiton stelleris . It has been observed feeding on gumboot chitons, where it uses its radula to cut through the dark outer layers on the dorsal surface of the chiton’s girdle in order to eat the yellow tissue beneath. They feed on a number of prey items, ranging from bivalves to other gastropods
Reproduction
They have separate sexes. Fertilization of the egg occurs in seawater. Eggs cases are attached to water.

Interesting facts
It may be confused with Amphissa, because its shell shows a similar mixture of fine spiral lines and axial ribs. It’s less slender than Amphissa,  its canal is better developed, and its aperture is not at all the shape being oval rather than nearly elliptical. The yellow-brown or orange-brown coloration, and the fact that the axial ribs cross the body whorl, enable one to distinguish it from a small specimen of searlesia. Often confused with larger rock snail, Ocinebrina sclera,

References

http://members.shaw.ca/bcshells/bcframe.html

http://people.www.edu/staff/cowlda/KeyToSpecies/Mollusca/Gastropoda/Prosobranchi/
Order_Neogastropoda/Suborder_Rachiglossa/Family_Muricidae/Ocenebra_lurida.html

Peterson Field Guides Pacific Coast Shells Percy A. Morris Houghton Mifflin Company Boston 2nd edition 1980 Canada

Shells & Shellfish of the Pacific Northwest Rick M. Harbo Harbour Publishing 1997
Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

We have somehow missed getting a photo of this Dogwinkle.. stay tuned!

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Neogastropoda
Family Thaididae

Genus Nucella
Species lamellosa (Gmelin,1791)
Common Name: Frilled Dogwinkle

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Superfamily Calyptraeoidea
Family Calyptraeidae
Genus Crepidula
Species adunca
Common Name: Slipper shell

This Crepidula was attached to a top snail and there were smaller individuals on top of the larger Crepidula

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

The black turban is frequently seen by divers at Race Rocks and here is exposed in the intertidal zone.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Trochida
Family Tegulidae

Genus Tegula
Species funebralis
Common Name: black turban snail

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Figure 1 In Fig. 1 the snails were purposely placed on the white quartz substrate to show the contrast between a shell of color 27 ( white ) and some of colors 1 – 10 ( Black to grey ).

See this file for an extended essay on Patterns of Color Polymorphism in Littorina sitkana
Littorina sitkana, the Sitka periwinkle, commonly has a fat, almost globuse shell which reaches a height of a little more than 1.5 cm and is decidedly higher rather than wide. It generally has strong spiral sculpting in the form of continuous ridges and furrows with the spire generally consisting of 3 whorls with a white band inside the aperture.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Subclass Prosobranchia
Genus Littorina
Species sitkana (Philipi 1845)
COMMON NAME: Intertidal Sea Snail – Periwinkle
As is the case with many intertidal gastropods, Littorina sitkana shows remarkable colour variablity which is a common occurance in both microhabitats sheltered and exposed to wave action.Some specimens are monotonously brown or grey, but others have lighter bands especially on the upper sides of whorls. The lighter areas and occasionally much of the body may be a rather pretty orange or yellow. Another periwinkle which is often found in the same intertidal area is Littorina scutulata

Previous studies have shown that there is close link between the shell colouration of periwinkles and their background substrate, that is, there is a very strong relation between the shades of the periwinkle’s shell and the colours of the rock – light cloured shells stayed on light shaded rocks and vice versa.

The influence of abiotic factors on the distribution of organisms is referred to in the file on Geology as an Abiotic factor.

REFERENCES CITED:

text/journal article references:

*Buckland-Nicks, J.A. and Chia,F.S.(1990).Egg capsule formation and hatching in the marine snail, Litorina sitkana,Phil.trans.Roy.Soc.Lond.Ser.B.326:159-176

*Exploring the seashore (p.69)

*Seashore life of the North Pacific Coast (p.122)

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Dec. 2001 Anneline Fisher

The checkered snails are Littorina scutulata

Domain Eukarya
Kingdom: Animalia
Phylum: Mollusca
Class:Gastropoda
Superfamily: Littorinoidea
Family: Littorinidae
Genus Littorina
Species scutulata
Common Name: Periwinkle

See the Extended Essay on Littorine Snails

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

The species has a sprial ridge near the body whorl (the axial ribs may not terminate at this ridge)without a sprial ridge near the base of the body whorl (the axial ribs continue to the base of this whorl) Usually with 7 axial ribs (intertidal and subtidal) DuShane,H.1979.
This photograph of this species with the anemone Tealia at Race Rocks was taken by Johan Ashuvud and G.Fletcher in 1980. The photo of Opalia on the glove was captured on video by David Roman (PC, yr23) in October, 1997. Note: there is also a top snail, Calliostoma on the red algae Lithothamnion in the upper right of the photo. David and Garry’s dive in 1997 was planned specifically to try to find this species of snail again and indeed they found it in the same location. It can be found on the main cliff, west of the jetty,  subtidal at 8-10m meters depth. (location Peg 3, Depth 8.5m), Typically it is always found on small patches of white shell fragments at the base of a cliff.

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Subclass Prosobranchia
Order Mesogastropoda
Superfamily Epitoniacea
Family Epitoniide
Genus Opalia
Species chacei
Common Name Chace’s Wentletrap
Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

The habitat of Nucella osterina ( previously Thais emarginata) in the pounding surf zone at Race Rocks.

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gasteropoda
Subclass Prosobranchia
Genus Nucella
Species canaliculata
Common Name: Northern Striped Dogwinkle

Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Channelled Dog Winkle, Nucella canaliculata
The habitat of Nucella, is in the lower intertidal zone

 
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Muricoidea
Family: Muricidae
Subfamily: Ocenebrinae
Genus: Nucella
Species: N. canaliculata
Nucella canaliculata (Duclos, 1832)
Other Members of the Phylum Mollusca at Race Rocks.

Return to the Race Rocks Taxonomy and Image File

The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.