Category Archives: Archived Video

Haematopus bachmani: Black Oystercatcher–The Race Rocks Taxonomy

Posted on by
2bloy

Black Oystercatcher, Haematopus bachmani photo by Ryan Murphy

Usually up to 6 pairs of the Black Oystercatcher, Haematopus bachmani nest at Race Rocks . They are also winter residents on the island, with numbers up to 100 individuals at times .

This link will connect you with the log showing the many
entries referring to Haematopus bachmani at Race Rocks.

ryansseton -Black oystercatcher

 

See  Ryan Murphy’s Flickr site for excellent images he took while he was ecoguardian at Race Rocks- 2009-2011

 

bloynest3mAn Oystercatcher nest demonstrates the fine art of camouflage
Classification:
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrate
Class Aves
Subclass Neornithes
Superorder Neognathae
Order Charadriiformes
Suborder Charadrii
Family Haematopodidae
Genus Haematopus
Species bachmani
Common Name :
Black Oystercatcher

Images for this slide show of mating Black oystercatchers were taken on the remote camera 5 by PB. May 29, 2006

This video of the black oystercatcher on the nest in June 2007 was screen-captured from camera 2 which was placed two metres from the nest for the duration of incubation.

June 24, 2007: Hatching day! By the end of the day three chicks are active. This video by Garry Fletcher is a compilation of events throughout the day.

BLOYJune8 -hatch
Link to this post from June 22, 2008 for the hatch of Black Oystercatchers near the boathouse captured from a live webcast on a video camera.

blkoybehav1sSee this video on Black Oystercatcher Behaviour

 

 

 

This post in 2024 has great photos of the chicks of BLOYs

For an interesting article on precocial birds such as these oystercatchers see this link.

The black oyster catcher is a jet black bird with a long red beak and pink legs. They grow to 43-44 cm, relatively large for shorebirds. The male and female adult birds are alike in appearance, but juveniles are dull brown. Race Rocks is home to at least six pairs during early May. The birds leave in early fall and return in later December, in numbers up to 30. In the Race Rocks Christmas bird counts numbers as high as 64 in 1997 have been recorded.

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
64 17 1 25 16 39 storm 16 35 22 0 storm
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
57 32 60 36 30 3 40 — — — — —

The birds often use distracting displays, pretending to have a broken wing or surprising other birds that invade their nests, but are otherwise non-territorial. Both parents incubate two or three eggs on average, and mates may stay together for several years. Locally, since there are no oysters, the bird is not so aptly named, but it does prey upon a variety of intertidal shellfish, including limpets, chitons and various snails. Birds of the same family occupying the same ecological niche are found throughout the shorelines of the world.
Their long, chisel-like beak is perfect for prying the shells open to feed on the soft flesh inside. The skull to the left was the product of predation by a river otter in 2001. The presence of the black oyster catcher nesting areas can be noted upon the discovery of piles of empty shells in the nooks and crannies of Race Rocks. Analysis of the different shells found in these piles has been done and it serves as an indicator of shellfish species diversity on the island, as well as the food web of the oystercatchers.

See the results of the Fall 1999 collection of shells from the midden of the oystercatchers.

Also go to the Lab on the Ecological Niche of the Black Oyster-catcher.

see this Video by Paul Omole of a Black Oystercatcher Feeding. –Sounds of Foghorn in the background .
Other Members of the Class Aves 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.

This file was originally started by Stewart Maudsley, Dec. 2001.

 

Enteroctopus dolpheni: Giant Pacific Octopus: The Race Rocks Taxonomy

Posted on by
rmoctopus eye

Enteroctopus dolpheni: Giant Pacific Octopus: The advanced eye of a mollusc. Photo by Ryan Murphy

Getting up close and personal was one of the things that former Ecoguardian Ryan Murphy was able to do very well underwater.. Consequently he produced the following interesting images from underwater.

We frequently encounter Octopus while diving at Race Rocks. They blend in very well with the algae and can change colors rapidly. Often the best way to see them is to spot their large (1-2 cm) white suckers in a crevice or cave. According to the website below, “Although it is very unusual to find an individual over 45kg, one large individual captured just near Victoria in 1967 weighed 70 kilograms (156 pounds) and was almost 7.5 meters ( 23 feet ) from arm tip to arm tip.

Smaller animals occur occasionally in low intertidal pools on rocky shores, larger individuals generally subtidal to depths of 100m; along North Pacific rim from northern Asia to California;

One of the largest octopus species known, the largest specimen on record with a total arm spread of 9.6m and a weight of 272 kg; dorsal mantle length usually over 20 cm; weight sometimes exceeding 50 kg; body ovoid, with extensive skin folds, red to reddish brown above, pale below; ocelli absent; arms 3-5 times body length, lacking specialized enlarged suckers and large truncate papillae; hectocotylus large, about one-fifth the length of the third right arm; with 12-15 lamellae on the outer demibranch of each gill; gill lamellae 25-29; ink dark brown; eggs measuring 6-8 mm by 2-3 mm, planktonic larva with a single row of chromatophores on each arm; borne in capsules on long stalks, these entangled and cemented together to form long festoons.

The Giant Pacific Octopus, (Enteroctopus dofleini , Hochberg, 1998) was formerly classified as : Octopus dofleini (Wulker, 1910)

 

Giant Pacific Octopus frequently appear at Race Rocks in the subtidal waters. They are also seen occasionally washed up in the intertidal zone where they contribute to the energy flow of the gulls and eagles. This individual which had died recently in June 2002, became the subject of a webcast and an impromptu dissection on the shore.

Video on Octopus necropsy

Domain: Eukarya
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order Octopoda
Suborder: Incirrata
Family :Octopodidae
Genus: Enteroctopus
Species: dofleini (Hochberg, 1998)
Common Name:  Giant Pacific Octopus
Although E.dofleini has been used extensively in laboratory studies, its natural history is still poorly known. The life cycle is thought to be 4-5 years. Eggs are laid throughout the year, though mainly in the winter, and development takes 5-7 months; hatching peaks in the early spring. The young are pelagic for a short period, probably about 1 month.

The three images above of a baby Octopus were taken in the intertidal zone near the docks by
Ryan Murphy in July 2004.

The adults feed on crustaceans (shrimps and crabs), mollusks (scallops, clams, abalones, moon snails, and small octopuses, and fishes ( rockfishes, flat fishes, and sculpins). Large crabs are stalked and then caught with a sudden flick of one or more arms; empty crab carapaces, shiny shells, and bones often litter the entrance to a lair. The octopus takes smaller shrimps and fishes by slowly arching its body over a seaweed bed, then suddenly pouncing, and enclosing the area in a canopy formed by the web membrane that joins the basal parts of adjacent arms. The sensitive arm tips are then inserted into the impounded area to search for food.

  • Two mesozoan parasites charactersictically occur in the kidneys of E. dofleini: Dicyemennea abreida and Conocyema deca.

This octopus is fed upon by seals, sea otters, dogfish sharks, lingcod, and man. It supports small commercial fisheries in Alaska, Canada, Washington, Oregon, and Northern California. Locally, it is also used by halibut fishers as bait.

Literature Cited:

Robert H. Morris, Donald P. Abbott, and Eugene C. Haderlie, Intertidal Invertebrates of California

Eugene N. Kozloff, Marine Invertebrates of the Pacific Northwest

octopus and diverLink to an assignment on Biodiversity submitted to us by
Shawna Millard Biology 202 at Bellevue Community College, Washington.

 

 

Return to the Race Rocks Taxonomy

This file is provided as part of a collaborative effort by the students, faculty and volunteers of Lester B. Pearson College .  This file was started by: Amanda Muscat PC yr 27, Dec. 2001.

Cepphus columba: Pigeon Guillemot–The Race Rocks Taxonomy

Posted on by

rmmar2609piggguil

Pigeon Guillemots arrive in early January, some still in their mottled winter plumage. Their numbers build and nesting takes place in late spring. A favourite foraging area is in the main channel in font ( to the North) of the Race Rocks docks. They may number up to 100 in the water, diving down in the current and coming up with small fish, especially gunnels.

Ryan Murphy has done some amazing telephoto shots starting in February of 2009 of Pigeon Guillemots such as those below.  They are included in a set here on his Flickr site.

rm2010pigguilskip rmguillemot4
rmguillemot2

rm2piguil copy

Four samples of photos of Pigeon Guillemots by Ryan Murphy

winterplumage-pigu

Winter Plumage on Pigeon Guillemots, photo by Pam Birley by the Remote control Camera 5

raisajan152011pigu

Winter Plumage of Pigeon Guillemot. photo by Raisa Mirza


Description: The pigeon guillemot has an average size of 12-14”. Its summer plumage is black with large white wing patches interrupted by black stripes.

It is interesting to note that in winter, its head and upper parts lighten slightly, however in all seasons feet and bill lining are brilliant red. In the spring it can be heard making a high whistle.

How and what they eat: The Pigeon Guillemot feeds by diving and taking up small fish. Some examples are: Penpoint Gunnels or “Blenny”, sand lance, smelt, and sculpins.

Habitat: This species resides in rocky coastal areas, with shallow inshore waters as its feeding grounds. Nest cavities are found amongst holes and rock crevices on the West, North East and South sides of Great Race Rocks. Some habitat for nesting was created years ago when blasting for the helicopter pad produced rubble under which they could tunnel..

rmgunnelandpigil copy

Ryan Murphy took this picture of a pigeon guillemot having just caught a gunnel.

Lumpenus sagitta, pacific snake prickleback captured by Pigeon guillemot

Lumpenus sagitta, pacific snake prickleback captured by Pigeon guillemot, Ryan Murphy photo.

Predators: Seagulls are predators of pigeon guillemot eggs. At Race Rocks, the main threat is predation by Bald Eagles, Peregrine falcons and nest predation by River Otters.

ahjuly3011pigguilchick

Summer ecoguardian Adam Harding was able to take pictures of a the chicks in a guillemot nest in the summer of 2011. The nest was located at the end of the low rock wall West of the science house

 

piguilnest

1 or 2 greenish or whitish, dark-spotted eggs are laid in a crevice or burrow. This nest burrow had been abandoned,perhaps due to predation, at the end of the season eggs were still present unhatched in the burrow. The light keeper’s assistant is shown here-1984-

Pigeon Guillemots

Pigeon Guillemots photo by Ecoguardian Courtney Edwards in March , 2014

The slide show above was made from pictures taken by Pam Birley in 2007

Kiprop made this video of the Guillemots jostling for position on the rocky shore on the West side of the island.

slide show of mating guillemots by Pam Birley was made from camera 5 screen captures.

Video of pigeon guillemots on the island and out in the passage where they dive and forage.[/caption]

Return to the Race Rocks Taxonomy and Image Gallery

Other Members of the Class Aves 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 of this taxonomy was done in Dec. 2001 by Anthony Woodside, PC Year 27

Ligia pallasii: Sea Slater –The Race Rocks Taxonomy

Posted on by

video of sampling of populations of Ligia sp

 

During the Johan Ashuvud project 2004, students explored the intertidal with Garry. They examined various organisms as well as the artificial tidepool.

In this video, we also get a chance to meet all the students taking part in the project

The central part of this video has a section on Ligia sp.

Sexual dimorphism in body proportions is marked in L.pallasii. Males, with their large, laterally expanded ephemeral plates, have a length/width ratio of about 1.6; females and immature males are narrower, with a corresponding ratio of about 2.1. Half- moulted males are occasionally found in which the rear half of the body has moulted and is abruptly significantly wider than as yet unmoulted front half, an odd sight, usually several days after the posterior moult.On the walls of cliffs and sea caves, the larger and broader males often cover and shield the females and juveniles.

L.Pallassi prefers sea cliffs. At Race Rocks, the loose upper intertidal rocks and crevasses on the Western side of the main island provide ideal habitat. There are differences in the osmoregulatory responses shown by these species associated with their behavior and ecology.The slower -moving pallasii lives permanently in cool, moist habitats characterized by fluctuating hypo-saline condition. L.Pallasii are air breathers with gill-like pleopods not equipped with tracheal trees.The respiratory pleopods must be kept moist to function properly.This is done by immersion or by dipping the tail in water in such away that the uropods serve as capillary siphons.

Ligia species are fed upon by birds, especially gulls, and by the intertidal crab. Life span of L.pallasii is 1.5 to 2 years , with breeding occurring in spring and early summer, and the average brood size is 48 plus or minus 11 young.The overall sex ratio is 1:1.

Domain Eukarya
Kingdom Animalia
Phylum or Division Arthropods
Class Crustacea (crustaceans)
Order Isopoda
Family Ligiidae
Genus Ligia
Species pallasii
COMMON NAME:sea slater

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- Palwasha Hussain Khel

 

Ophiothrix spiculata: Brittle star–The Race Rocks Taxonomy

Posted on by

Ophiothrix spiculata is a common species among algal holdfasts at Race Rocks. Its arm’s spines are especially long, and each one has a number of small thorns on it. the color is extremely variable but it is generally reddish brown, there may be some orange on the disk, too. in spite of all the color variation, this species is unmistakable because of its thorny spines.

Two sets of video on brittle stars are seen here. They were observed off the docks at Race Rocks in about 10 meters of water. Note the other organisms that live in the area also.

 

This brittle star is lives on the rocky sea floor, from shallow waters to great depths. Brittle stars are related to sea stars. These marine invertebrates move very slowly along the sea bed. More than 2000 species of brittle stars exist in the world.
It has long, thin, spiny arms that radiate from a flat central disk; the arms do not touch each other at their bases. Many of the arms are forked. If a brittle star’s arm is cut off, it will regenerate.
Usually the central disk in these brittle stars is under 2 cm) in diameter. They have an exoskeleton and vary in color. They do not have a brain; they have a simple ring of nerve cells that moves information around the body. Tube feet located along the arms sense light and smells.

This juvenile brittle star was filmed in the lab by Sylvia Roach using a Digital camera attached to a dissecting microscope at 4X

Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Ophiuroidea
Order Ophiurida
Family Ophiodermatidae
Genus Ophiothrix
Species spiculata
COMMON NAME: brittle star

They often gather in large groups and collectively filter food from the circulating water. When roused from a hiding spot their best form of defense is to crawl away-

The projections on the five arms of this brittle star look like many tiny hairs, but are actually spines. That being said, they are gentle, very delicate creatures that do not harm humans. They are nocturnal (feed and move about primarily at night); they stretch out to catch food particles, passing the bits down to the central mouth.
To avoid predation, if a predator catches one of its legs, it has the ability to swim off, leaving that leg behind, and it can regenerate a new one!

Waving arms point out the home of the stars. Those aren’t worms, they’re brittle stars, sea star cousins that hide themselves under rocks and in the holdfasts of kelp, especially in the Pterophyga at Race Rocks.

For comparison with another species, see this image in our ecological equivalents file an image of a large 20cm species from the Galapagos:

 

 

 

Reference Cited:

Eugena N. Kozloff , Seashore Life of the North Pacific Coast

http://www.mbayaq.org/efc/living_species/default.asp?hOri=1&inhab=142

 

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.

 March October 2003-  Rahilla (PC)

Leptasterias hexactis The Race Rocks Taxonomy

Posted on by

The six rayed sea star is found both intertidally and subtidally at Race Rocks. They are one of the smaller sea stars.

Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroidea
Order Forcipulatida
Family Asteriidae
Genus Leptasterias
Species  hexactis  (Stimpson,1862)
COMMON NAME: Six- rayed Star
Introduction
Description: Radius 2″ (51 mm), 6-armed ( note the species name hexactis referring to the six arms.). Green, black, brown, or red, sometimes mottled. Disk moderate-sized with 6 fairly broad arms; spines on upper surface dense and mushroom-shaped. rarely do we find these at Race Rocks exceeding 15 cm in length.
Habitat: On rocky shores. We frequently find these when doing intertidal studies or when diving in shallow water at Race Rocks. Range British Columbia to s. California.
Discussion: L. hexactis eats small snails, limpets, mussels, chitons, barnacles, sea cucumbers, and other species, including dead animals. It produces yellow, yolky eggs that stick together in a mass after fertilization. These are brooded under the disk of the female until they hatch as miniature sea stars after 6 to 8 weeks. The small six-rayed sea stars of the West Coast are quite variable and have presented problems of identification. The only other species currently recognized is the Small Slender Sea Star (L. pusilla) which has sharp spines and longer, thinner arms than L. hexactis, and is a light gray-brown or reddish color. It also has a very limited range from San Francisco to Monterey Bay. It reaches a radius of 1″ (25 mm).
Echinoderms have a few important aspects in common. They have bony ossicles in their body. They have a water-vascular system which pumps water through the madroporite. They also have small jaws that are supported by the water-vascular system. And they have tube feet which they use to attach to objects, for protection, as well as to obtain food. They have radial symmetry and most can regenerate lost limbs.

 

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.

 December 2001(PC)

Mediaster aequalis: Vermillion star–The Race Rocks Taxonomy

Posted on by

Mediaster in its habitat. Photo by Dr.A..Svoboda

Snail predation

 

Vermillion stars are seen frequently by divers in the 0-15 meter depth at Race Rocks.

 

Information.
Bright red (vermillion in fact) with large plates along its five arms. To 20 cm. Common just below the surface on low tides but hardly ever high and dry. These are abundant subtidally – you may find plenty after storms or extreme tides.

This Vermillion star male was emitting sperm while in the tank at Pearson College in early January 2004 . This went on for more than three hours. Millions of sperm are broadcast into the water where they may have a chance encounter with eggs which are simultaneously released into the current by the females. Of the great numbers of eggs and sperm released only a few are fertilized and actually make it to maturity. This is a good example of
r-selection in the population.

– http://www.wavelengthmagazine.com/1998/jj98neigh.htm

Mediaster aequalis is one of the smaller sea stars ranging in size from three to seven inches. It is found on many types of beaches at very low tides.

– http://www.geocities.com/oscmarinetech/Animals.htm#Vermillion%20Star

The vermillion sea star is common in shallow subtidal waters. Its feeding area stretches to nearly the tip of each arm on the underside. The vermillion star, so named because of its colour can be found from the Alaskan Peninsula, south to southern Caifornia.

Colour: Vermillion aborally, more orange orally; tube feet red to flesh colour.

Habitat: common on rocks shell, sand, gravel, pebbles and mud.

Feeding: diet varies with substrate and season; eats encrustin sponges and bryozoans on ock; seapen.

Reproduction: breeds from March to May; number of eggs in 65mm sea star estimated at 1,800 per year. the eggs measure 1 to 1.2mm and are bright opaqe orange. It is estimated that Vermillion sea stars reach sexual maturity within four years.

Speed: The sea star can move anywhere between 27 and 40 cm per minute.

Reference: The Sea Stars of British Columbia, Lambert, 1981, British Columbia Provincial Museum, Victoria

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.

Dec 2001 Damien Guihen (PC yr 27)

Henricia leviuscula The Race Rocks Taxonomy

Posted on by

 

Blood stars are seen frequently by divers in the 0-15 meter depth at Race Rocks. They are planktonic feeders.

Kingdom Animalia
Phylum Echinodermata
Class Stelleroidea
Sub Class Asteroidea
Order Spinulosida
Sub Order Leptognathina
Family Echinasteriade
Genus Henricia
Species Leviuscula
Common Name Blood Star

The Blood Star is characterized by its brilliant red or reddish-orange color. Its comparatively small and graceful its body is only 10 to 12 cm from the tip of one ray to the tip of the one across from it. It has an arm radius to 8.9 cm, usually less; its disk is small, its arms are long, tapering, and are usually five in name (sometimes four or six); it has an absent pedicellariae; its aboral surface has a tan to orange-red or purple color., often banded with darker shades, and bearing many groups of short spinlets arranged in a fine network.
Habitat: Common on protected sides of rocks, under rocks, and in caves and pools, more frequently where rock is encrusted with sponges and bryozoans, low intertidal zone, subtidal to over 400 m.

The sea star feeds on bacteria and other tiny particles, which are captured in mucus and swept to the mouth by ciliated tracts. It may also feed by applying the stomach to the surfaces of sponges and bryozoa.

Breeding habits in the sea star vary with size. Smaller females brood their eggs in a depression around the mouth formed by arching the arms. Larger females discharge eggs directly into the water and do not brood them. The sperm have spherical heads and the eggs are orange-yellow and yolky, and development is direct.

REFERENCES CITED:

1. Robert H. Morris, Donald P. Abbott, and Eugene C. Haderlie,Intertidal Invertebrates of California, 1980, Stanford University

LINKS:

http://elib.cs.berkeley.edu/photos/fauna/sci-invertebrate.html

http://enature.com/fieldguide/showSpeciesSH.asp?curGroupID=
8&shapeID=1072&curPageNum=9&recnum=SC0074

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.

 Dec 2001Tania Melendez (PC yr.27)

Strongylocentrotus purpuratus: Purple sea urchin– The Race Rocks Taxonomy

Posted on by

 

 

 

 

Purple Urchins and Californianus sp mussels at a “zero” level tide on the west side of Great Race Rocks.
July 2000

The purple sea urchin is about 10 cm. across, spines up to 2cm. and is bright purple. Its body “skeleton”, called the test, is shell like with bumps and holes from which the moveable spines and tube feet extend .The spines are used for protection, movement and for trapping drifting algae. It has a claw like mouth with 5 teeth-like plates. It is composed of over 60 shells and is called Aristotle’s lantern and is located on the underside or oral side of its body. The anus and the genital pores are on the aboral side of the sea Urchin.

In February, 2004 we had a note from CECIERJ requesting permission to use our video of the purple sea urchin in media being prepared for their undergrad distance learning courses. By offering these courses, the consortium CEDERJ contributes to bringing high quality free education to the inner cities of the Rio de Janeiro State. As well as permitting such use of our resources, we have added for them, an introduction by one of our Brazilian students, Rita who helped us make this video in Portuguese about the Sea Urchins and Echinoderms..

Diet: The Sea Urchin feeds on algae, plankton, kelp, periwinkles, and occasional tiny barnacles or mussels.

They are eaten by crabs, sunflower stars, snails, sea otters, some birds, fish, and people.

Reproduction: Fertilization in Sea Urchin is external, the female release several million tiny, yellow jelly-coated eggs at a time. The gametes join the water column as planktonic forms .

Behaviour: Although they often live in sheltering holes that they have worn in the rocks and they have also been observed to makes holes in solid steel, this behaviour is not evident at Race Rocks. Most of them live in shallow water here, They move surprisingly fast on their tube feet and spines. Moving their feet by a hydraulic water vascular system which creates suction in the end of the foot by pulling water out of the madreporite. They can also regrow broken spines.

The following images show the structural features on the test of a dead purple sea urchin. The image was produced by scanning.


This image shows the aboral view of a purple sea urchin.The dark patch in the middle is the anus. These were dead specimens.Thus the spines are missing.

Domain Eukarya
Kingdom Animalia
Phylum Ecinodermata
Class Echinodea
Order Echinoida
Family Strongylocentrotidae
Genus Strongylocentrotus
Species purpuratus
common name Purple Sea Urchin

The lower image shows the oral view of a purple sea urchin. The hole in the middle is its mouth with the sharp edges its 5 teeth. Note the pentaradial symmetry.

Parastichopus californicus The Race Rocks Taxonomy

Posted on by

 Video of Albinism and Leucism in Sea Cucumbers

 

 

 

 

Video of escape response when attacked by Pycnopodia sp.

 

 

 

 

Video of a male sea cucumber releasing sperm

 

 

 

Emily finds a partially albino (pinto?) Parastichopus while diving near Church Island… just up the Strait from Race Rocks. 

 

 

DESCRIPTION:

The California Sea Cucumber grows up to 50cm long. They are the largest cucumbers in B.C. waters. They range in colours from red in juveniles to brown or mottled brown, with all white individuals occurring rarely. They are covered on the dorsal side with flesh coloured papillae, and on the ventral side by tube feet. A circle of peltate feeding tentacles surround a subterminal mouth, directed ventrally at the anterior end. Oxygenated water is forcibly pumped into the sea cucumber’s respiratory trees in several successive inhalations, and then deoxygenated water is forcefully expelled. Eye-witness accounts have noted small fish being expelled with this force of water, perhaps living in symbiosis with the California sea cucumber.

RANGE:

Gulf of Alaska to Cedros Island, West of Lower California. Intertidal to 249m. Common on mud, gravel, shell, rock rubble or solid bedrock, from exposed coast to sheltered inlets. Greatest densities occur in quieter waters where organic sediments settle on hard surfaces. Harvesting of Sea Cucumber is also done by divers, throughout their range.

FEEDING, BEHAVIOR, AND BREEDING:

Sea cucumbers feed as they move along the bottom, traveling up to a maximum of 3.9m a day. They gain nutrition from organic material in sediment, mostly form bacteria and fungi. California Sea Cucumbers cease feeding and become dormant from September to early March. Once they reach maturity at four years of age, they will migrate to shallow water to spawn from late April to August, although this timing varies with location. Fertilization takes place in open water. Free swimming larva feed on plankton for 35-52 days before settling to the bottom. Parastichopus californicus has few natural predators. Sunflower starts sometimes eat them, and the sea cucumber reacts strongly by rearing back and flexing violently to avoid being eaten. They are harvested commercially in B.C., Washington, and Alaska for meat, and limits have been set for the amount that may be caught. When disturbed, as other sea cucumbers, it will contract and squirt a powerful stream of water from its posterior end. Five pairs of muscle bands which run the length of the body help this organism in contracting and escape from sea stars. Perhaps one of the most interesting features is this organisms ability to regenerate new organs for winter after expelling them during its dormant phase. It seems there is controversy as to whether sea urchins expel or reabsorb their organs. Recent evidence cited by Philip Lambert of the RBC museum in Victoria(1997) indicates that the sea cucumbers reabsorb their organs.

FURTHER INFORMATION NEEDED:

-further study at Race Rocks of commensal fish living in respiratory tree

-behaviour studies

-colouration, how long it takes to occur in full pigmentation, as a white individual found near Race Rocks has recently begun to change tan colour–later development?

-mechanism of absorbing/ejecting and regenerating organs

WEBSITE LINKS TO SEA CUCUMBERS:

Sea cucumber fishery – Pacific Region
http://www.pac.dfo-mpo.gc.ca/ops/fm/shellfish/Sea_Cucumber/biology_cucumber.htm

A paper by Phil Lambert on Sea Cucumber Taxonomy
http://rbcm1.rbcm.gov.bc.ca/nh_papers//taxing.html

REFERENCES CITED:

Carefoot, Thomas (1977), Pacific Seashores : A Guide to Intertidal Ecology
Lambert, Philip (1997), Sea Cucumbers of B.C., Southeast Alaska and Puget Sound
Morris, Abbott, Haderlie (1990), Intertidal Invertebrates of California
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.  – Sarah Trefry Dec 2001 (PC)

Other Members of the Phylum Echinodermata at Race Rocks 
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File