Ocinebrina lurida : Lurid rock snail–The Race Rocks Taxonomy

snailcol2-1

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.

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and Image File
pearsonlogo2_f2The 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.

 

Nucella lamellosa: Frilled Dogwinkle–The Race Rocks Taxonomy

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
pearsonlogo2_f2The 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.

 

Macoma sp. — The Race Rocks Taxonomy

rmmollusc

Macoma sp. Photo by Ryan Murphy

 

We are not sure of this classification of this bivalve but just had to use this image that Ryan took at Race Rocks, as it shows association with two other classes of Molluscs,  the chitons and the gastropods.

Here is a possible classification from ITIS Report
Animalia: – animals
Subkingdom:  Bilateria
Infrakingdom:  Protostomia
Superphylum: Lophozoa
Phylum: Mollusca
Class: Bivalvia
Subclass: Heterodonta
Order: Veneroida
Superfamily: Tellinoidea
Family: Tellinidae
Genus: Macoma (Leach,) 1819
Species: Macoma brota Dall, 1916 – heavy macoma

 

taxonomyiconReturn to the Race Rocks Taxonomy and Image File
pearsonlogo2_f2The 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 2005–Ryan Murphy

 

Geitidoris heathi : (Heath’s dorid)– The Race Rocks Taxonomy

Geitidoris heathi  (Heath’s dorid) photo by Rayn Murphy

Geitidoris heathi (Heath’s dorid) Photo by Ryan Murphy

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Opisthobranchia
Suborder: Nudibranchia
Superfamily: Doridoidea
Family: Discodorididae
Genus: Geitodoris
Species: G. heathi
Geitodoris heathi (MacFarland, 1905)
Synonyms Discodoris heathi

Other Members of the Phylum Mollusca at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The 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.  Oct 2010 , by Ryan Murphy

 

Aldisa tara : The Race Rocks Taxonomy

rmaldisatara

Aldisa tara photo by Ryan Murphy

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Doridoidea
Family: Cadliidae
Genus: Aldisa
Species: A.tara
Aldisa tara Milen, 1984

Tentative identification only.. This is a fairly rare nudibranch, only named recently.

 

This file is provided as part of a collaborative effort by the students, faculty, volunteers and staff of Lester B. Pearson College– Oct 2010 , by Ryan Murphy

Dendronotus diversicolor: coloured dendronotid–The Race Rocks Taxonomy

rm241010dalbusmetandl
This image by Ryan Murphy is rather stunning because it shows the nudibranch in contact with the colonial tunicate Metandrocarpa sp.
The identifying features of Dendronotus diversicolor are the 4 pairs of gills and a white line that goes from the last gill pair to the end of the tail.

ah06610dendrotus

This is a rather unique picture by Ryan Murphy of breeding nudibranchs

Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Tritonioidea
Family: Dendronotidae
Genus: Dendronotus
Species: diversicolor
Alder & Hancock, 1845

 

dendronotusdivers

Dendrotus diversicolor photo by Adam Harding

 

Other Members of the Phylum Mollusca at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The 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.  Ryan Murphy

 

Tonicella undocaerulea: Blue-waved Chiton

chitonblue4

Blue-waved chiton , Tonicella undocaerulea Photo by G. Fletcher


We frequently encounter this 4 cm. chiton while diving at Race Rocks. It occurs subtidal at 10 meters depth. It also occurs in the lower level tidepools as the photos above illustrate. These chitons strip off several species of calcareous encrusting algae from the rock substrate, They are equipped with a radula or rasp-ike tongue containing iron filings.

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Polyplacophora
Order Chitonida
Family Tonicellidae
Genus Tonicella
Species undocaerulea
Common Name: Blue-waved chiton
Other Members of the Phylum Mollusca at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The 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.

 

Crepidula adunca: Slipper shell–The Race Rocks Taxonomy

Domain Eukarya
Kingdom
Phylum
Class
Superfamily
Family
Genus Crepidula
Species adunca
Common Name: Slipper shell
Other Members of the Phylum Mollusca at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The 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.

 

Tegula funebralis: Black Turbine Snail–The Race Rocks Taxonomy

Domain Eukarya
Kingdom
Posted in ER Warden Report, Phylum Mollusca, Species | Tagged

Littorina sitkana: Periwinkle–The Race Rocks Taxonomy

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 ).

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.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The 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