This rather unique image of a sea slug eating a suberites sponge which houses a hermit crab was take by Adam Harding , Sept, 2010
A Sea Lemon that has just laid its eggs. Ryan took this image underwater at Race Rocks in the spring, 2009, it was formerly called Anisodoris nobilis
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Opisthobranchia
Family Nudibranchia
Genus Peltodoris
Species nobilis
Common Name: Sea Lemon
 Return to the Race Rocks Taxonomy and Image File |
Ryan Murphy
Blue-waved chiton , Tonicella undocaerulea Photo by G. Fletcher
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.
| 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. |
Keyhole limpets have a distinctive mantle-covering response when they are approached by a predatory sea star such as Pycnopodia.sp
Physical Description:
it has a small oval opening at the top of its short, conical shell. Although the keyhole limpet superficially resembles “true” limpets, its soft anatomy reveals an important difference. True limpets draw water into their mantle cavity on the left side, pass it over a single gill and discharge it on the right side. Keyhole limpets draw water in both sides, where it flows over paired gills before flowing out through the “keyhole” aperture at the peak of the shell. Size: Length is about 75 mm
Global distribution:
The Rough Keyhole Limpet can be found anywhere in coastal regions from Afognak, Alaska, to Baja California. It is found primarily in low intertidal areas, and has been seen up to 40 feet subtidally in the south (Morris et al. 1980).
Habitat:
The Keyhole Limpet clings tenaciously on and under large rocks in the sub to low intertidal. They can also be found on large kelp stipes. Their strong foot allows them to thrive in some intertidal areas where turbulent wave action is prevalent.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
SubClass Prosobranchia
Order Archaeogastropoda
Family Fissurellidae
Genus Diodora
Species aspera
Common Name: Key-hole limpet
Feeding: This particular limpet is an omnivorous grazer. It feeds by scraping rocks with its radula. Various bryozoans are its food of choice, but it also consumes algae, as well as some sponge species.
Predators:
Sea stars, the limpet responds by raising its mantle up over the outside of its shell, a behavior that may prevent the sea star from gripping the shell surface.
Reproduction:
Keyhole limpets have separate sexes, and sexually ripe individuals can be found during any season of the year. Eggs and sperm are released into the water in mass quantities and larval settlement ensues.
One interesting Fact: Recent studies suggest that this animal’s unique apical opening is not only associated with sanitation, but also plays an important role in inducing passive flow through the mantle cavity. In studies where the keyhole of Diodora aspera was blocked (either naturally or experimentally) no evidence of damage to the mantle cavity or associated organs was found. In these experimental trials, water entered ventro-posteriorly with respect to the gill tips, and exited over the head region (near the anus). The apical opening proved unnecessary as a means of waste removal. Researchers did find however, that the keyhole played an essential role in allowing water to flow passively through the mantle cavity. Thus, it is thought that this function of the apical opening may have been just as significant as its role in sanitation in terms of limpet evolution
References:
Wylam, B. 2001. “Diodora aspera” (On-line), Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/
Diodora_aspera.html.
Guide of Marine Invertebrates.- Alaska to Baja California
Daniel W. Gotshall.- Sea Challenges.
Monte Rey – California, USA 1994
| Other Members of the Phylum Arthropoda 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.
October 2005- Claudia (PC yr 32) |
| Physical Description: The average size of this species is 4-6 cm in length (shell) and 3-4 cm wide, with a low profile and rounded apex found forward of its center. The shell of this species is relatively smooth, conical or oval in shape, sculptured with coarse, flat-topped ridges. The color of the surface varies, though externally brown or green with radiating with white spots or lines.Habitat: The Notoacmea scutum are found “between the high and low-tide lines” on smooth surfaces, usually rocks, while showing a “tidal rhythm of activity” which occurs more often at night. Reproduction: Spawning occurs, most abundantly, from autumn to spring, but can happen throughout the entire year. Spawning results in the external fertilization via males releasing sperm into the females, who then release their fertilized eggs into the flowing water. Range (global): |
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Sub class Prosobranchia
Order Archaeogastropoda
Family Acmaeidae
Genus Notoacmea
Species scutum
Common Name: Checkered Limpet
Reference:
www.nmarinelife.com/htmlswimmers/n_scutum.html
www.nbl.noaa.gov/(zeajfizhdjfdsf45hn4n3k55)/itis.aspx?tsn=69716
http://academic.evergreen.edu/t/thuesene/animalia/mollusca/gastropoda/notoacmea/scutum.html
www.people.wwc.edu/staff/cowlda/keytospecies/mollusca/gastropoda/prosobranchia/order_patellogastropoda/family_lottiidae/tectura_scutum.html
¬ Intertidal Invertebrates of California
¬ Reproduction and Development of Marine Invertebrates of the Northern Pacific Coast Data and Methods for the Study of Eggs, Embryos, and Larvae
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.
Original text for this file was done by Shaterra Redd PC student year 32 . 2005 |
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.
I checked the tidepool #4 again in June of 2024 to see if the white periwinkle still existed there and I found this one
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. |