Category Archives: Invertebrate

Solaster stimpsoni: Stripped Sun Star–The Race Rocks Taxonomy

Posted on by

This is a frame taken from the video beside. The blue color is because white light does penetrate to a depth of 8 metres, so only the parts of the picture that are illuminated from the video light show the true colors.. Note in the video how objects appear to change color when illuminated, but, they don’t actually do so. In the foreground is a broooding anemone , red with a band of babies at its girth. The pink coral is hydrocoral.

“Invertebrates at Race Rocks” is an introductory piece on a few of the invertebrate phyla. This was one of the first hinted streaming videos done by the Pearson College divers in April 2000. There is a good section on Soalaster Stimpsoni in the film. It was taken by Rowena and Shamsher on a Sony Digital camera, and edited by Hannah and Garry on a G4 Macintosh Computer using iMovie.

 

Physical Description
It has 8-12 arms, but usually it has 10 arms, which has length is about 23 cm. The diameter about 20 inches (51 cm). And the central disc about &Mac185; of total diameter. It&Mac226;s mouth just below the central disc. And, as the common sea star, it uses its tube feet which under main arms to move.

Global Distribution
This kind of sea star could be found at Bering Sea to Salt Point California (Trinidad Head, Sonoma Country, Kodiak Island and Oregon) and Pacific Northwest (Sunrise Beach and Gig Harbor).

Physical Description
It has 8-12 arms, but usually it has 10 arms, which has length is about 23 cm. The diameter about 20 inches (51 cm). And, as the common sea star, it uses its tube feet which under main arms to move.

Habitat
This sea star is possible to find at rocky bottoms but sometimes in sand or in the lowest zone.
Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroida
Order Spinulosida
Suborder Eugnathina
Family Solasteridae
Genus Solaster
Species stimpsoni
Common Name: Stripped Sun Star, Sun Star, Stimpson’s
Feeding
This animal is a carnivore. It usually feed at sea cucumbers (the most favorite foods), tunicates, lampshells, sea pens, brachiopods, holothurians, sea squirts and nudibranch.

Predator
The predator of this animal is Sunflower Star ( Solaster dawsoni).

Reproduction
It reproduces sexually. It is breeding from February to March. Gametes are discharge into water. The eggs then become larvae and start to metamorphosis for about 40-50 days.

Interesting Thing
It can curl its arms up over its body to take on a spherical shape. This allows it to tumble across the seafloor in the along-shore currents.

References
Alaska Fisheries Science Center, Sun Sea Star Solaster Stimpsoni. Internet
British Columbia Creature Page. Internet
Edmonds Discovery Programs. Internet
Gotshall Daniel (1994) Guide To Marine Invertebrates. California
King Country (1999) Sun Star &Mac246; Solaster Stimpsoni. Internet
Lambert Philip (1965) Sea Star. Vancouver, Canada
Morris Robert, Donald A & Eugene H (1980) Interditial Invertebrates of California. California
Photo Gallery. Internet
Strathmann Megumi (1987) Reproduction And Development of Marine Invertebrates of The Northern Pacific Coast. Friday Harbour Laboratory
Verrill (1880) Solaster Stimpsoni. Internet
Yates Steve (1988) Marine Wildlife. Washington

 

Other Members of the Phylum Echinodermata 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 2006 Winda (PC year 32)

Crossaster papposus: Rose star–The Race Rocks Taxonomy

Posted on by

We dont find the rose star very often when diving at Race Rocks . These sunstars are scavengers and are omnivores, ir predators of anything edible. Sunflower stars and Northern sunstars are its predators. 

Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroidea
Order Velatida
Family Solasteridae
Genus Crossaster
Species papposus,

(C. papposus Linnaeus, 1776)

Common Name: Rose Star

Other Members of the Phylum Echinodermata 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.

Garry Fletcher

Pisaster ochraceus: Purple or ochre star–The race Rocks Taxonomy

Posted on by

Along the low intertidal shores of Vancouver Island, this sea star is frequently found. It is amazing however that this is the only specimen we have been able to find at RaceRocks. Since these sea stars inhabit the lower intertidal zone they are subject to strong forces by crashing waves. This single individual with a diameter of over 50 cm. has a protected niche at the inside base of the cliff in a crevice on the small intertidal island on the West side of Great Race Rocks. Its main food, Californianus mussels are abundant all around so it has probably been in this same position for more than 20 years.

The Pisaster ochraceus or ochre star as it is more commonly known can be found along the coast of the Pacific Ocean from the Baja California up to Alaska. However it is more common around the Northwest coast as it is a cold water species. Ochre stars typically have five arms and are dotted with small white blunt spines which form line patterns. The bottoms of their arms are covered in small extendable suction like feet.

The ochre star mainly eats mussels, snails, limpets, chitons, barnacles or sea urchins. By moving on top of its prey, the ochre star then opens the shell and everts its stomach onto its prey digesting it. The ochre star is also prey to birds and sea otters. The ochre star plays an important role as a keystone species. It has been noted that in areas where the ochre star has been removed, the ecological diversity has gone down.

Interestingly enough, the ochre star can withstand being out of water for an extended period of time. It is able to lose a substantial amount of water. It can also regenerate a lost arm, though this may take up to a year. Ochre stars have been known to live up to 20 years.
Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroidea
Order Forcipulatida
SuborderAsteriadina
Family Asteriidae
Genus Pisaster
Species ochraceus
Common Name: Purple or ochre star

References:
http://hmsc.oregonstate.edu/projects/rocky/oochstar.html
http://animaldiversity.ummz.umich.edu/site/accounts/information/Pisaster_ochraceus.html

Other Members of the Phylum Echinodermata 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.    Alex Chan  ( PC year 31)

Diodora aspera: Keyhole limpet– The Race Rocks Taxonomy

Posted on by

 

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 
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.

 October 2005-  Claudia (PC yr 32)

Notoacmea scutum : Checkered Limpet -The Race Rocks Taxonomy

Posted on by
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):
Research has been shown that the Notoacmea scutum species can be found in the Aleutian Islands and Mexico and from Alaska to Baja, California.

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.

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.

Original text for this file was done by Shaterra Redd PC student year 32 . 2005

 

Biotic Asociations at Race Rocks

Posted on by

 

The California Sea Cucumber exhibits an escape response when approached by the Sunflower Star.

Also see the video on Phyllospadix and its biotic associations

This mussel will no doubt have a competition for food with this barnacle.

Mussels have a number of associations.
  The whale barnacle living as a commensal on Gray Whales
You will find below a set of photos from our photo archives depicting two or more organisms in a biotic association. These associations fall into one of several categories: mutualism, commensalism, parasitism etc. By going through the many organisms in the Race Rocks Taxonomy, you will find explanations for these and other biotic associations.
Coraline Algae and Epiactis Boring Sponge (Cliona) and Purple- Hinged Rock Scallop (Hinnites) Cup Coral (Balanophyllia) Epiactis and Encrusting Algae (Lithothamnion)
Basket Star and soft coral
 Basket Star and sea urchin
 Abalone (Haliotis) and Lithothamnion
Anthopleura xanthogramica with internal green coccoid algae Brittle Star and Kelp Holdfast Brittle Star
Nudibranch and the orange hydroid Garveia Swimming Scallop and Encrusting Sponge Scallop with blue eyes

Lopholithodes mandtii : The Puget Sound King Crab–The Race Rocks Taxonomy

Posted on by

We often encounter these very large Puget Sound King Crabs in the calm backwaters of Race Rocks. Juveniles may be found among the cobble. Sea urchins and other echinoderms form their diet.

 

Paul Michaluk a fomer PC student from New Zealand, captured this picture on the left of Garry holding a  a Lopholithodes brought up by the divers who were back for a PC alumni reunion

Another former student, Barb Holman, took the picture on the right of Garry demonstrating the size of a Puget Sound King crab at Race Rocks to Trish Holman in April, 1998
Domain Eukarya
Kingdom Animalia
Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Decapoda
Family Lithodidae
Genus Lopholithodes
Species mandtii
Common Name: Puget Sound King Crab

See a post by our ecoguardian Mike Robinson in 2012

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. 

 

Eudistylia vancouveri: Northern Feather Duster worm–The Race Rocks Taxonomy

Posted on by
0708tubeworm

Eudistylia vancouveri: photo by G.Fletcher

The Feather Duster Tube worm is often associated with floating docks on the southern part of Vancouver Island. At Race Rocks, there are no floating docks but Eudistylia inhabits the protected rock crevasses of the lower intertidal zone. It can not withstand drying out too long so being in this tidal level will provide a maximum of an hour exposure at the lowest tides. While exposed in the air, their feather like gills are retracted, and the leathery parchment-like tubes are pinched closed at the opening. Underwater, the gills when released, are often banded a deep red and purple colour.

Domain Eukarya
Kingdom Animalia
Phylum Annelida
Class Polychaeta
Order Canalipalpata
Suborder Sabellida
Family Sabellidae
Genus Eudistylia
Species vancouveri
Common Name: Northern Feather Duster Worm
This file is provided as part of a collaborative effort by the students, faculty, staff, and volunteers of
Lester B. Pearson College
2005
 Garry Fletcher

Phoxichilidium femoratum: Sea spider– The Race Rocks Taxonomy

Posted on by

 

pycnogonidLaura Verhegge in October 2005, collected two of these specimens while taking samples of invertebrates in the area where the tidal current turbine generator is to be installed. The diameter including legs is about 1cm. Note the short stubb as it should have 8 legs.  This video was taken with a microphotography apparatus. They were both found at 20 metres depth in association with the hydroids and the club tunicates.

Kingdom:Animalia
Phylum: Arthropoda
Subphylum:Chelicerata
Class: Pycnogonida
Latreille, 1810
Order: Pantopoda
Gerstaecker, 1863
Genus:Phoxichilidium
species:femoratum

Membranipora serrilamella: Kelp-encrusting Bryozoa

Posted on by

The colonial marine bryozoan Membranipora serrilamella, formerly referred to as Membranipora membranacea. produces a planktonic larva that is encased by a triangular bivalved shell. Following a relatively long free-swimming phase, the larva settles as an epizootic colony on the blade of laminarians and other subtidal marine algae. It then undergoes a metamorphosis to become the sessile progenitor of the colony, referred to as the ancestrula”.

Encrusting colonies are typically found on marine algae on the lower shore to shallow water. Found encrustating in kelps and other large seaweeds, especially common on the brown algae Laminaria, but can also be found growing in rocks, glass, floats or other.
Description: This epiphiytic bryozoan forms encrusting lacy matlike colonies of very small, rectangular aurozooids 0.42 x 0.13 mm. with tubercules or short spines in the corners. Each zooid has lateral calcified walls that contain ventral incalcified bands providing flexibility; A frontal membrane completely roofs the space between the supporting side walls with a lophophore (feeding tentacles) visible within. Tower zooids may also be present, where the frontal membrane projects upwards in a columnar way. Forms white, disc-like colonies, approx. 1 mm high and up to and over 100 mm wide. Zooids are rectangular and for together neatly in radially arranged rows that grow outward and branch into new rows as the pattern frows wider.
Additional information: Colonies may vary in size. Membranipora membranecea grows quickly (several mm/ day) in response to predation from sea slugs and in order to maintain its position on the kelp frond. Prolific growth is favoured by fast flowing water which provides food and oxygen. Egg production occurs once a year in the spring; the larva (cyphonautes) is planktotrophic and is the most abundant and largest coastal larva in Britain between June and August. The larva settles in late simmer-early autumn.
Natural history: Colonies are made up of hundreds or thousands of individual zooids, which are not much larger than a pond head. Their eight week growing season falls between late spring and early autumn. During this time, how they grow is dependent upon their success in the competition for space. The interaction between colonies can be cooperative to aggressive depending upon their size. Small colonies communicate by using electrical signals. Large colonies use runners called stolons from which new zooids bud from to mediate aggressive behaviors.

Domain- Eukaryota
Superphylum Prostomia
Phylum Bryozoa
Class  Gymnolaemata
Order Cheilostomatida
Suborder: Malacostegina •
 Family:  Membraniporidae •
Genus: Membranipora de Blainville, 1830
species: M. serriamella

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. March 8 2005- Fredy ( PC 32)