Category Archives: Phylum Mollusca

Coralline Algae Discoveries, Impossible Invasive Plants

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Weather:

  • Visibility 15+ NM
  • Sky clear
  • Wind 5-10 knots SE
  • Sea state: calm

Visitors/Marine Traffic: 

  • One medium sized catamaran passed through race passage this morning drifting on the current
  • This afternoon we were joined by Guy and Christine, who brought us some generator hardware and spent a bit of time enjoying the beautiful weather.
  • Quite a bit of commercial traffic outside the reserve today including barges of logs and shipping containers.

Ecological: 

  • There are quite a few beginnings of seagull nests now. They have become more aggressive, and now fight each other over space. We have seen some pairs mating.
  • We have been finding coral-like white fragments in the intertidal since last year, but until now have not been able to identify what they could be. Today we found some that were not white, but red! This insight has led us to believe that this is coralline algae. Amazingly, this article states that these unassuming structures can continue to grow forever (!) if left undisturbed and have growth rings that be counted, just like trees!
  • As Gary Fletcher mentions in this post, prostrate knot weed is one of the invasive species here on Race Rocks. We noticed that it is particularly efficient at growing in places where no other plants are able, therefore it’s beginning to spread in rocky areas. It has notably spread to the rocky areas on the SW side of the island where no other flora nor fauna has managed to establish itself.

 

The Flag is Back

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Weather: 

  • Sky overcast, some clear patches (not much solar power generated today)
  • Visibility 15+ miles, no fog
  • Wind 10-20 knots W
  • Water calm. Some interesting standing wave patterns lately.

Boats/Visitors: 

  • On Thursday Greg came in the afternoon to top up our water supply. Pearson alum Norbert (currently alum in residence) also came along for the ride to check out our solar panels and provide suggestions for future improvements. Pearson maintenance volunteer Jimmy also stopped in for the night to visit race rocks before he goes home to Mexico. Safe travels!
  • We had many hands on deck, so we were able to successfully repair and raise the flagpole.
  • Yesterday Greg visited with a group of college guests who toured the island.

Ecological: 

  • The sea lions have started to haul out on the N + S/SW sides of Great Race Rock.
  • The oyster catcher chicks have grown to be nearly as big as their parents and are flying all over!
  • The seagull chicks are getting bigger and when rival adults attack they now fight back. On Thursday we spotted a chick with one eye pecked out and were concerned that it would not survive. Fortunately, when we checked later it was doing well.
  • There have been large numbers of black turnstones present this past week, 30+ at once

 

 

 

Extreme Tides & Extraordinary Critters

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Weather: 

  • Visibility: 10-14 miles
  • Wind: 10-20 knots
  • Sky: Slightly cloudy clearing to sunny and clear
  • Water: rippled

Boats/Visitors: 

  • Yesterday there were 20+ whale watching vessels in the reserve.
  • Today we had a group of 9 from Pearson College visit and tour the island.

Ecological:

  • Lately we have been having very low tides, and today we spotted two gumboot chitons on the jetty track in an area that would not normally be exposed.
  • The younger goslings are learning to swim!
  • The two large male elephant seals appear to be beginning to moult. Today we noticed that one of them has some cracking skin in his chin area.
  • Over the past few days we have noticed more bald eagles, and notably a few young ones.

 

 

Corolla spectabilis: Pteropod–The Race Rocks Taxonomy

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Pteropods are occasionally found in the plankton that passes by Race Rocks and are found distributed throughout the Atlantic and Pacific Oceans..They have a transparent body with no external shell. An internal gelatinous pseudoconch provides protection and skeletal support. A continuous plate is formed by the oval wings which are marked by indentations.A long proboscis partially fused with the wing plate.The pteropod has a wingspan of up to 8cm. It lacks radula and jaws and it has a distinctive dark gut nucleus.Because it is planktonic, its biotic associations include predation by anything that eats jellyfish.

REFERENCE: ”Pacific Coast Pelagic Invertebrates” by David Wrobel and Claudia Mills—Note: This source had an error which was pointed out to us by Moira Galbraith of DFO:—-“I think that your video in the Race Rocks portion of the website is actually of Corolla spectabilis. The 12 mucous glands on the anterior lateral borders of the wing plate are a species characteristic; C.calceola will have 18. Also according to Carol Lalli, only Corolla spectabilis occurs in the eastern Pacific.
See http://faculty.washington.edu/cemills/ActaErrata.html for an update.
Domain: Eukarya
Kingdom: Animalia
Phylum: Mollusca
Subclass: Opisthobranchia
Order: Thecosomata
(Suborder)(Pseudothecosomata)
Family: Cymbuliidae
Genus: Corolla
Species: spectabilis
Common Name: Pteropod
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.

 

Ocinebrina lurida : Lurid rock snail–The Race Rocks Taxonomy

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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.

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.

 

Nucella lamellosa: Frilled Dogwinkle–The Race Rocks Taxonomy

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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

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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

 

Granulina margaritula: Pear-shaped margaritula– The Race Rocks taxonomy

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Granulina margaritula the “Little Pearl” is a prosobranch gastropod belonging to the Marginellidae family that ranges from Southern Alaska to Panama. The bright colouration shown in this photo comes from the animal’s “mantle” which is an extension of the “dorsal body”. The epidermis of the mantle can secrete CaCO3 to create a shell.

To see G. margaritula’s shell and mantle: http://calphotos.berkeley.edu/cgi/img_query?enlarge=0000+0000+03…
A special thank you to Dr. Alan Kohn at University of Washinton for his help in identifying G. margaritula.

This is the first one photographed underwater at Race Rocks

Compare the size Granulina margaritula to Flabellina verrucosa beside it in this photo.This “Three-lined” aeolid is seasonally abundant from Baja to Alaska (Behrens, 1991). Aeolids are opisthobranch gastropods known as sea slugs because they have lost their shells. This photo shows the nudibranch’s “oral tentacles” (bottom), ridged sensory antennae called “rhinophores”, “cerata” which contain stolen stinging cells for defense, and a “propodial tentacle”. This aeolid is common year-round at the Race Rocks Ecological Reserve where it is often observed feeding on hydroids such as Tubularia.
Macro images by Ryan Murphy

 

Other Members of the Phylum Echinodermata 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. January 2011, Ryan Murphy

 

 

Cuthona divea

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From Marine Life of the Pacific by Lamb and Hanby, we see that the rose-pink cuthona, or Correa’s aeolid Is a very bushy species,( living fro intertidal to 20 metres depth from BC to California. The first three rows of cerata (gills) begin ahead of its rhinophores (sensory organs).It feeds on hydractinid hydroids whose color it closely matches. Macro image by Ryan Murphy

Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Nudibranchia
Family Tergipedidae
Genus Cuthona
Species divae
Common Name: Rose-pink Cuthona (Er.Marcus,1961
Other Members of the Phylum Arthropoda 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.

 January 2011 Garry Fletcher

Limacea cockerelli: Race Rocks Taxonomy

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On a background of bryozoans, a macro image by Ryan Murphy, 2011

Photo by Adam Harding, 2011

This is a very small dorid nudibranch, 15 mm in length, with elongate orange-tipped club-shaped tubercles around dorsal margin. Rhinophores are bright red-orange.
We haven’t photographed this nudibranch before, but due to its small size it has probably been overlooked until now.
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Opisthobranchia
Infraorder: Doridina
Family Triophidae
Genus Limacea
Species cockerelli
Common Name: Laila cockerelli (Macfarland,1905)