Monthly Archives: February 2002

Eupentacta quinquesemita:white sea cucumber–The Race Rocks Taxonomy

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Here are the tentacles extended on a cluster of Eupentaca.Their bodies are hidden. Photo by Dr.A. Svoboda

GENERAL DESCRIPTION

Eupentacta quinquesemita is stiff to touch due to abundant calcareous ossicles in the skin and tube feet. The body grows 4-8 cm in length. The non-retractile tube feet give it a spiky look. It has five rows of tube feet (four tube feet in width) with smooth skin between. The two ventral feeding tentacles are smaller than the other eight. This character is useful for identifying this species when only the tentacles are visible. The expanded tentacles are creamy white with tinges of yellow or pink at the bases.

Skin ossicles: numerous large, porous, ovoid bodies dominate the ossicles but among them are small, delicate baskets. The latter are important in differentiating this species from Eupentacta pseudoquinquesemita.

HABITAT

They are fairly common under the rocks and in cervices, low intertidal zone on rocky shores; common on concrete piles and marina floats in Monterey harbor, Vancouver (British Columbia) to Morro Bay (San Luis Obispo. Co). High densities of this species occur in strong currents. Juveniles (up to 1 cm) settle among hydroids and small algae in high current areas and on floating docks.

REPRODUCTION

Eupentacta quinquesemita is a suspension feeder. It spawns from late March to mid May. The female produces eggs greenish in color, 370 to 416 um diameter: the male releases sperm, and fertilization takes place in open water. The yolky egg develops into a non-feeding evenly ciliated larva. In culture, the larva grows to the armoured stage in 11 to 16.5 days.

 

PREDATORS

The predators of Eupentacta quinquesemita are: the Sun Star (Solaster stimpsoni), the Sunflower Star (Pycnopodia helianthoides), the Six-armed Star (Leptasterias hexactis) and the Kelp Greenling (Hexagrammos decagrammus).

BIOTIC ASOCIATION

The internal parasite, Thyonicola americana, a shell-less wormlike snail, attaches elongated coils of eggs to the intestine of E. quinquesemita. The larvae are released into the intestine and probably scape through the anus. Any parasites that are ejected by evisceration perish.

FEEDING

Is by shovelling of sediment into the mouth and digesting the microfauna within. No direct feeding is required. Is omnivore.

DomainEukarya
Kingdom Animalia
Phylum Echinodermata
Class Holothuroidea
SubclassDendrochirotacea
Order Dendrochirotida
Family Sclerodactylidae
Genus Eupentacta
Species quinquesemita
Common name White sea cucumber

REFERENCES

Lambert, P. 1997. Sea Cucumbers of British Columbia, Southeast Alaska and Puget Sound. UBC Press, British Columbia Canada. 166 pages

Morris, R., P. Abbott, and E. Haderlie.1980. Intertidal Invertebrates of California. Standford University Press, Stanford, California. 690 pages.

Kozloff, E. 1996 . Seashore Life of the Northern Pacific Coast. Fourth Edition. University Of Washington Press. Seattle and London. 370 pages.

 

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.

 Patricia  (PC year28)

Orthasterias koehleri: Rainbow sea star– The Race Rocks Taxonomy

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General description:

Arms radius to 21cm, gets fairly big to 50cm; disk small, with five slender arms; aboral surface bearing prominent sharp spines and a conspicuous ruff of pedicellariae, which are white; color vivid; varying from rosy pink with a gray mottling, to bright red mottled or banded with yellow, the spines whitish or lilac.

Habitat

Uncommon, on mud, sand, and kelp but occurs in the very low intertidal zone, on shaded rock surfaces. It is more common at scuba depths and extends to 250m, being found from Alaska to Southern California.

Feeding
Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Asteroidea
Order Forcipulatida
Family Asteriidae
Genus Orthasterias
Species koehleri
COMMON NAME: Rainbow sea star

Orthasterias koehleri feed on small snails, limpets, clams, scallops, chiton, barnacles, and tunicates. They can dig clams out of cobbled bottoms, and use the pull of the tube feet to spread apart the outer layer of a clam shell until a small opening is made between the valves. The stomach is then inserted through the opening and the clam digested.

Reproduction

To expose the gonads in a rainbow sea star, make a 1-2 inch cut in the ray near the junction with the disk, push the digestive gland gently aside to expose the underlying gonad, then firmly grasp the gonoduct with forceps and cut it free from the gonopore. Fragments of gonad can be removed, but the cut gonad will leak gametes into the body cavity. Suture the incision or leave it to heal unsutured in clean and strongly flowing seas water. Recovery is better if the insicion is small, the digestive gland is undamaged, and all air is removed from the body cavity. This method has been used with success.

References

Intertidal Invertebrates of California, Between Pacific Tides
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.

Esrah Ugurlu (PC year 28

Usando Internet para Protección Ecológica

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 Usando internet para protección ecológica
m.m.burkle@sussex.ac.uk

Por MARTHA BURKLE
GRUPO REFORMA


El domingo de la semana pasada tuve la suerte de visitar un interesante proyecto en el que la web es utilizada para crear una dinámica experiencia educativa en estudiantes de preparatoria de todas las regiones del globo. El proyecto “Race Rocks” (www.racerocks.ca/) toma su nombre de una isla ubicada en el punto geográfico más al sur de Canadá. La isla tiene una historia de más de un siglo, cuando en 1860 las fuerzas británicas vieron la necesidad de establecer un faro náutico para poder orientar sus navíos en una zona marítima en la que las corrientes de agua y los vientos cambian de manera vertiginosa.

En 1974, el Colegio Pearson fue abierto en la región de Victoria, Columbia Británica, como parte de un proyecto internacional llamado “United World Colleges” -Preparatorias Unidas del Mundo – (www.uwc.org/uwchome.html).

Fundado en 1962 con el soporte de la ONU, la misión del proyecto internacional es formar a jóvenes entre 16 y 19 años de edad, procedentes de todas las regiones del mundo, en los valores de responsabilidad, vida comunitaria, conciencia ecológica y en la promoción de los ideales de justicia, paz, comprensión y cooperación internacional. A nivel mundial existen solamente 10 colegios como este (dos en norteamérica, uno en sudamérica, tres en Europa, uno en Africa y tres más en Asia), y año con año, estudiantes de preparatoria buscan ser seleccionados entre los 100 mejores (cada colegio admite solamente a cien estudiantes por año), en el aspecto académico y de compromiso con la comunidad.

El proyecto de investigación de ‘racerocks.com’ nace prácticamente con la fundación del colegio de Pearson, al sur de Canadá. Diseñado para proveer contenidos y experiencias de investigación en los diversos programas educativos dentro del colegio, los profesores de Pearson College alimentan la página web con el propósito de motivar en sus estudiantes el interés por la vida marina en la isla.

Utilizando una interesante combinación entre tecnología de punta y cuadernos de notas, los creadores del proyecto (con el patrocinio de Apple y Sony) instalaron cámaras digitales en diversos puntos de la isla para la transmisión en vivo, 24 horas al día, de la actividad marina en la zona. Dos cámaras registran la ecología marina en las costas de la isla, una cámara transmite vida acuática en las profundidades del océano, y una más es utilizada para eventos especiales en vivo. Seguramente usted, querido/a lector, compartirá conmigo cierta fascinación al conocer este único lugar, si visita la web que le permitirá escuchar en vivo los diversos sonidos producidos por focas, leones marinos, elefantes marinos, gaviotas y demás habitantes de la región.

A pesar de ser una red tecnológica relativamente pequeña, la tecnología involucrada en el proyecto de Racerocks.com es bastante sofisticada. Prácticamente todos los aparatos que configuran la red pueden ser adquiridos en el mercado, pero lo que los hace únicos es la original visión que los integró. Ambos, el colegio y la isla, comparten una red local. La infraestructura de la red es provista de velocidad por switches y routers que utilizan módems rápidos para proveer video y audio. Como la isla en sí está ubicada a varios kilómetros de la costa del colegio, era importante que la red tuviera alta capacidad y lograr esto fue difícil. Al inicio del proyecto, tres eran las opciones más viables: el uso de una conexión vía satélite, la transmisión inalámbrica, o la fibra óptica marina.

El proceso de toma de decisión respecto a cual seria la tecnología más propia, tuvo que tomar en cuenta factores económicos y de conservación del medio ambiente. El uso del satélite apareció como una vía muy costosa y poco probable; por su parte, utilizar fibra óptica submarina, era costoso también y además presentaba algunos problemas técnicos y otros involucrados con la protección ecológica del área. Finalmente, la opción del uso de microondas apareció como la más viable.

Radios modelo “Tsunami” y equipos de construcción de la compañía de telecomunicaciones “Glen Tel” fueron adquiridos e instalados en la parte superior del faro náutico en la isla.

Esta mañana, y mientras escribo esta columna, Racerocks.com está transmitiendo en vivo imágenes submarinas desde la isla a un congreso que se lleva a cabo simultáneamente en California. Probablemente lo más interesante de estas imágenes es el hecho de que son los mismos estudiantes, chicos y chicas en edad adolescente, quienes se encuentran ahí, haciendo la transmisión debajo del agua. Los y las estudiantes involucrados en el proyecto, registran eficientemente los cambios ecológicos en la isla, y comparan sus datos con los obtenidos por previas generaciones en el siglo XIX y cuidan de los equipos electrónicos.

México tiene a dos de sus mejores estudiantes de preparatoria en el Colegio de Pearson. Fue emocionante platicar con ellos y ver su compromiso de trabajo y dedicación.

La autora es doctoranda en Políticas de Ciencia y Tecnología en la Universidad de Sussex, Inglaterra

Reprinted with permission of the author.

Eagles and geese

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Monday, February 18, 2002
Good Evening
TEMPERATURE: Max. 7.8C Min. 5.9C Reset 6.5C  Rain 1.0 mm
MARINE LIFE: 16 mature 7 immature Bald Eagles,2 pairs of geese
on the island today.
HUMAN INTERACTION: 2 nd Nature out with visitors this morning,
and back in the afternoon for a dive off west race.
1 pleasure boat through M.P.A. today
posted by Carol or Mike S at 6:33 PM
Good Morning
WEATHER: Sky Overcast Vis. 15 Miles  Wind West 4 Knots  Sea Rippled
posted by Carol or Mike S at 7:14 AM

Strongylocentrotus droebachiensis: Green sea urchin –The Race Rocks taxonomy

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See this green urchin in the video and compare it with the purple and red urchins

 

Green Sea Urchin: average size is 50-60 mm, but may reach a maximum size of about 85 mm.

Distribution: The green sea urchin is one of the most widely distributed of all Echinoderms. It has a circumpolar distribution, which extends into the Arctic regions of both the Atlantic and Pacific Oceans. It commonly inhabits the rocky subtidal zone from the low-tide mark down to a depth of 1200 m, but also occurs intertidally in tide pools.

 

 

Diet: The green sea urchin primarily grazes on seaweeds (kelp being its preferred food source), but will also consume a wide variety of organisms including mussels, sand dollars, barnacles, whelks, periwinkles, sponges, bryozoans, dead fish, and – when hungry enough – other sea urchins.

This shows the grazing action of sea urchin teeth, arranged in a complex assemblage of small bones, the five teeth gouged out this star pattern in the stipe of a Pterygophora.

 

The skeleton of the sea urchin is called a “.test”. The radial symmetry is reflected in the placement of all the tube feet holes. Here you can see the size of a green urchin compared to a red urchin

 

 

 

Reproduction: Green sea urchins release their gametes into the water column where the eggs are fertilized by the sperm. The sexes are separate. The resulting larva (termed an “echinopluteus”) undergoes development planktonically for a period of one to several months before settling on the sea floor and metamorphosing into the adult form. Reproduction occurs on an annual cycle with spawning occurring in the spring, generally between February and May, but sometimes as late as June.  See the Lab on Sea urchin Embryology.

This video from underwater Safari shows a wolf eel crunching a sea urchin…

Behavior: Where urchins occur at high density, destructive grazing can produce habitats devoid of seaweeds. These areas may be termed “sea urchin barren grounds”.. When sea urchins are removed from these sites, either manually or by disease, the reduction in grazing pressure often results in the development of highly productive kelp forests. These kelp beds provide shelter for a wide variety of marine organisms (e.g. fish, lobsters, crabs, sea stars, bivalves, gastropods, bryozoans) and the habitat is typically much more diverse than barren grounds. Hence, sea urchins are one of the principal factors controlling habitat diversity in the rocky subtidal environment.

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.

Aldo Caixeta (PC yr 28)/strong>

Scyra acutifrons: Sharp-nosed crab– The Race Rocks Taxonomy

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This individual is well camouflaged and you can see the other associated organisms around it. The red circle is a serpulid worm

Geographic range is Alaska to Mexico

Size: up to 45mm (1.7 inches)

Domain Eukarya
Kingdom Animalia
Phylum Arthopoda
Subphylum Crustacea
Class Malacostrata
Superorder Eucarida
Order Decapoda
Family Epialtidae
Genus Scyra
Species acutifrons
Common Name:Sharp-nosed crab 

This is a reasonably common crab especially around the dock and higher subtidal areas. The adult males have large claws that they seem to keep folded in. The nose is flat and pointed. The crab shells are often covered with barnacles and other growth as can be seen in this picture. This species puts relatively little effort into decorating, occasionaly placing a small pieces of material on its rostrum but generally appearing to just let organisms colonize its roughened carapace. It feeds primarily on detritus and sessile invertebrates, and sometimes it associates with sea anemones. Females with eggs have been found all months but April to May and September to October. Number of eggs carried ranges fom 2,700 to 16,300.

References:

http://www3.bc.sympatico.ca/kerryw/creature/sharp.htm

Jensen G.C. 1995. Pacific Coast Crabs and Shrimps. Sea Challengers, Monterey, CA. p. 21.

Kozloff, E.N. 1983. Seashore Life of the Northern Pacific Coast. University of Washington Press. Washington. 370 pages.

Morris, R., P. Abbott, and E. Haderlie. 1980. Intertidal Invertebrates of California. Stanford University Press, California. 690 pages.

 

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.

Sumak Serrano (PC year 28)

Urticina piscivora: Fish-eating anemone

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upiscivora

U.piscivora photo by Dr. A. Svoboda

Urticina piscivora is one of the largest Northern Pacific sea anemones. You can find this type of species from La Jolla, Mexico to Alaska, it can grow about 8 inches (20 centimeters)
Urticina piscivora was called Tealia Anemone. The structure of this anemone consists of a bag formed by three layers a non-cellular “mesoglea” between two tissues, an outer layer called “epidermis” and an internal called gastrodermis.The interior of the bag is the gut also known as gastrovascular cavity. Sheets of tissue or septa extend out form the body wall dividing the gut into compartments wich manifests on the surface as tentacles. Many of the anemones have their tentacles in multiples of six.

Domain Eukarya
Kingdom Animalia
Phylum Cnidaria
Class Anthozoa
Genus Urticina
Species piscivora
Common Name Fish eating anemone
urtricina

Utricina photo by Pearson College divers.

Inside the centers of septa, they are often elaborated and called septa filaments .Heavily loaded with stinging cells or nematocysts. Stinging cells are used to immobilize their prey.Urticina piscivora eats small fish.

Sexes are generally separated in sea anemones, but some species may be serial hermaphrodites, functioning males during one spawning and females at a later time. The typical reproductive pattern is to spawn into the water where fertilization occurs. Asexual reproduction occurs in some sea anemones some can reproduce by splitting by two (binary fission), and others will leave little piece of the pedal disk behind as they move, (pedal laceration),

This file is provided as part of a collaborative effort
by the students, faculty, staff and volunteers  of  Pearson College UWC.		 Feb. 2002 Nora Lozano Yr.28

Return  to the Race Rocks Taxonomy

Epiactis prolifera : Brooding Anemone The Race Rocks Taxonomy

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epiactis

Epiactis prolifers G.Fletcher photo

Brooding anemones,  Epiactis prolifera are a small species. The height of an expanded specimen does not often exceed about 3cm. The basic colour is brown to greenish brown, but it is sometimes red, pinkish, blue,  red or dull green. They are usually found in the subtidal zone (at zero tidal level, especially on intertidal rock benches or surge channels, and in rocky areas with wave action, often in areas with crustose coralline algae. Brooding anemones are also regularly found on the leaves of eelgrass. Red or pinkish red specimens are sometimes found on rocky shores, but rare on eelgrass. They are rarely exposed to the air, not being able to tolerate exposure to the air and sun. Brooding anemones, like other sea anemones, attach themselves to something solid so as not to get carried off by currents or wave action.

The oral disk of brooding anemone is generally marked with radially arranged white lines. The pedal disk and column have similar lines, though they may not be as sharp. The numerous young regularly found on the pedal disk do not originate there by asexual budding, but are derived from eggs fertilized in the digestive cavity. The motile larvae, after swimming out of the mouth, migrate down to the disk and becomes installed there until they become little anemones ready to move and be able to feed themselves. Click on the photo on the left to see a belt of these juvenile anemone around the pink adult which has retracted.

 

Brooding anemone usually spend most of their lives in one place, but some have the ability to move, they can only travel three to four inches an hour. Sometimes the brooding anemone hitch a ride on hermit crabs or decorator crabs. Brooding anemones can protect the crab and if the crab is a messy eater, the sea anemone can pick up bits of food from the crab and eat it. This is one of the biotic associations of Epiactis prolifera. This is also an example of mutualism, where both the organisms living together benefit from each other.

Brooding anemones eat small fish and shrimps. Much of their prey is crustaceans. The brooding anemones capture its prey with its deadly stinging tentacles. Its mouth and tentacles are located on the top of its body. Their stalk and tentacles are bristling with an arsenal of stinging cells, or nematocysts. The double walled microscopic stinging cells contain a hollow thread with a minute harpoon-like barb at the end. When the cell is stimulated either physically or chemically, it explodes and fires the barb and attaches the thread with incredible force into the potential predator or prey and simultaneously injects a potent poison. Usually hundreds and thousands of these stinging cells are activated at once, which can paralyze prey or deter most predators.

After being immobilized, the prey which may include shrimps, crabs, jellyfish or small fish is manoeuvred by tentacles towards the mouth where it is consumed whole. Any indigestible material or waste will be excreted through the mouth as well. Even with its formidable arsenal of nematocysts, anemones are a favoured prey for other animals. Many nudibranchs feed on anemones and are not only immune to the anemones defenses, but have the ability to absorb un-detonated packets of stinging cells which are then used for the nudibranchs own defense. Sea stars and fish are also some regular predators. If a brooding anemone, like any other sea anemones, is torn apart, then each part becomes a new brooding anemone.

References:Eugene N.Kozloff: Marine Invertebrates of the Pacific Northwest
Seashore Life of the Northern Pacific Coast
Megumi F.Strathmann: Reproduction and Development of Marine Invertebrates of the Northern Pacific Coast
Doug Pemberton: Divers Magazine February 2001
http://divermag.com/archives/feb2001/anemones-feb01.html
Sea Anemones: http://library.thinkquest.org/J001418/anemone.html

This file is provided as part of a collaborative effort by the students, staff, faculty and Volunteers of Lester Pearson College February 2002 Sangeeta Asre Fiji IslandsPearson College: Year 28

 

Epiactis Prolifera: Brooding Anemone- The Race Rocks Taxonomy

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broodinganemone

A field of Epiactis prolifera, showing the high variability in colouration– photo by Ryan Murphy.

Brooding anemones or Epiactis prolifera are a small species: the height of an expanded specimen does not often exceed about 3cm. The basic colour is brown to greenish brown, but it is sometimes red, pinkish red or dull green. They are usually found in the subtidal zone (zero tidal zone), especially on intertidal rock benches or surge channels, and in rocky areas with wave action, often in areas with crustose coralline algae. Brooding anemones are also regularly found on the leaves of eelgrass. Red or pinkish red specimens are sometimes found on rocky shores, but rare on eelgrass. They are rarely exposed to the air, not being able to tolerate exposure to the air and sun. Brooding anemones, like other sea anemones, attach themselves to something solid so as not to get carried off by currents or wave action.

 

The oral disk of brooding anemone is generally marked with radially arranged white lines. The pedal disk and column have similar lines, though they may not be as sharp. The numerous young regularly found on the pedal disk do not originate there by asexual budding, but are derived from eggs fertilized in the digestive cavity. The motile larvae, after swimming out of the mouth, migrate down to the disk and becomes installed there until they become little anemones ready to move and be able to feed themselves. You can see the belt of juvenile anemone in several of the images above.

Domain Eukarya
Kingdom Animalia
Phylum Cnidaria
Class Anthozoa
Order Actiniaria
Family Actiniidae
Subclass Zoantharia
Genus Epiactis
Species prolifera
Common Name: Brooding Anemone
rmbrooding

Brooding Anemone photo by Ryan Murphy

Brooding anemones eat small fish and shrimps. Much of their prey is crustaceans. The brooding anemones capture its prey with its deadly stinging tentacles. Its mouth and tentacles are located on the top of its body. Their stalk and tentacles are bristling with an arsenal of stinging cells, or nematocysts. The double walled microscopic stinging cells contain a hollow thread with a minute harpoon-like barb at the end. When the cell is stimulated either physically or chemically, it explodes and fires the barb and attaches the thread with incredible force into the potential predator or prey and simultaneously injects a potent poison. Usually hundreds and thousands of these stinging cells are activated at once, which can paralyze prey or deter most predators.

After being immobilized, the prey which may include shrimps, crabs, jellyfish or small fish is manoeuvred by tentacles towards the mouth where it is consumed whole. Any indigestible material or waste will be excreted through the mouth as well. Even with its formidable arsenal of nematocysts, anemones are a favoured prey for other animals. Many nudibranchs feed on anemones and are not only immune to the anemones defenses, but have the ability to absorb un-detonated packets of stinging cells which are then used for the nudibranchs own defense. Sea stars and fish are also some regular predators. If a brooding anemone, like any other sea anemones, is torn apart, then each part becomes a new brooding anemone.

References:

Eugene N.Kozloff: Marine Invertebrates of the Pacific Northwest
Seashore Life of the Northern Pacific Coast
Megumi F.Strathmann: Reproduction and Development of Marine Invertebrates of the Northern Pacific Coast
Doug Pemberton: Divers Magazine February 2001
http://divermag.com/archives/feb2001/anemones-feb01.html
Sea Anemones: http://library.thinkquest.org/J001418/anemone.html

This file is provided as part of a collaborative effort by the students, staff, faculty and volunteers of Lester B. Pearson College February 2002 Sangeeta Asre- Fiji Islands
Year 28