Clavularia sp. : Pale Soft Coral– The Race Rocks Taxonomy

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A colony of Clavularia sp. by Ryasn Murphy, April 2010. The individual polyps can be seen in unusual clarity.

See Ryan’s underwater set on Flickr with a range of invertebrates:

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This is an enlarged close up of part of the image above.

 

This species is currently being identified. Each polyp is smaller than 1.2cm. Although it may appear at first as a hydroid, it is actually a soft coral, in known as an octocoral because of the eight tentacles. It is found in small patches a few cm. in diameter on the rocks right off the docks at Race Rocks in 10-12 metres of water.

 

Dr. Anita Brinckmann Voss identified this sample and indicated that it is related to Gersemia the soft pink coral. She has seen it in samples from Race Rocks before but not in such a large colony. She also indicated that a new species has been described from the North Pacific and she will try to get us a reference to it.

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Another photo by Ryan Murphy of a Clavaria colony. The colour difference here is unexplained so far.

Domain Eukarya
Kingdom Animalia
Phylum Cnidaria
Class Anthozoa
Subclass Octocorallia
Order Alcyonacea
Family Clavulariidae
Genus Clavularia
Species sp .
Common Name: Pale soft coral

Octocorals on Coral reefs make up a large portion of the species there. The potential medicinal uses of several species of clavularia have been published. The abstract of one such study on Clavularia viridis is shown below:
Lin YS, Khalil AT, Chiou SH, Kuo YC, Cheng YB, Liaw CC, Shen YC. of the Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, Republic of China.
Abstract
Chemical investigation of the nonpolar extract of soft coral Clavularia viridis resulted in isolation of five new prostanoids, designated as claviridic acids A-E (1-5, resp.), in addition to the known clavulones I-III. Their structures were determined on the basis of spectroscopic techniques, especially HR-ESI-MS, CD, and 2D-NMR experiments. The isolated marine prostanoids exhibited potent inhibitory effect on PHA-induced proliferation of peripheral blood mononuclear cells (PBMC), as well as significant cytotoxic activity against human gastric cancer cells (AGS)

This file is provided as part of a collaborative effort by the students, faculty, staff and volunteers of
Lester B. Pearson College
April 2010
Garry Fletcher

Balanophyllia elegans: Orange Cup Coral–The Race Rocks Taxonomy

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Close up of Balanophyllia. Photo by Dr.A.Svoboda

The orange cup coral is one of the few true corals. It is found from Oregon to Southern California and also in British Columbia.. It is found in low intertidal zones and at Race Rocks it is very abundant, often associated with the brooding anemone and encrusting tubeworms of the 8-10 metre level. It is usually found on and under shaded rocks, on the sides of surge channels and under ledges.

Its physical characteristics include the following: It has a stony, cuplike, calcareous, external skeleton. It has polyps coloured bright orange to yellow. Balanophyllia elegans transparent tentacles bearing wart-like batteries of nematocysts are present in the marginal portion of their discs. The polyps nearly completely retract into the skeleton. The orange cup coral feeds on living and dead animal matter using its tentacles.

Food is caught primarily in the tentacles, but in addition the mouth may open widely, permitting their mesenteries with their nematocyst-laden margins to trap food. Studies done on the orange cup coral and a few similar organisms showed that the tentacles have organelles called spirocysts which resemble nematocysts and evert to produce tangles of sticky tubules. These spirocysts may be important in capturing prey or in attaching coelenterates to the substratum or both. The orange cup coral reproduces by releasing eggs into the parents gastrovascular cavity, where they are fertilized and undergo development to the planula stage before release to the ocean. These then settle on a rock substrate and metamorphose into tiny polyps, which then secrete a skeleton.

Domain Eukarya
Kingdom Animalia
Phylum Cnidaria
Class Anthozoa
Subclass Zoantharia
Order Scleractinia
Family Dendrophyllidae
Genus Balanophyllia
Species elegans
Common Name: orange cup coral

References

Kozloff, E.N. 1996 Marine invertebrates of the Pacific Northwest.

Morris, Abbott, Haderlie 1980, Intertidal Invertebrates of California.

This file is provided as part of a collaborative effort by the students, faculty, staff and volunteers of Lester B. Pearson College Dec 2002 Udochukwu Obodo
(PC yr29)

Gersemia rubiformis: Sea strawberry–The Race Rocks Taxonomy

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Gersemia rubiformis –Photo by Dr. A.Svoboda

In the following video, the soft pink coral Gersemia rubiformis is highlighted. It grows at 7-10 meters over a 3 square meter area off peg #3.  note the retraction of the colony when it is disturbed. Also note the other associated invertebrates in the same area.

Ed note: I have found that the QuickTime videos would not play if I was using Chrome as my browser, so by typing chrome:plugins in the address bar , then finding QuickTime, you can then click enable to re-enable the plugin.

if that doesnt work, switch to Firefox or another browser.
The following video shows in close details the characteristics of the soft pink coral (Gersemia rubiformis) found at Race Rocks. Soft corals are mostly sub-tidal. A soft coral has spicules of calcium carbonate within it, so it is moderately firm, but it does not have a completely calcified skeleton, like that of reef-building corals of warmer seas, or even like that of the cup coral of our coast. The polyps of soft corals have eight tentacles, each with delicate side branches. This establishes their relationship to sea pens and to most of the colonial reef-building corals. This colonial invertebrate forms a lumpy colony, sometimes 10 or 15 cm in diameter, whose colors range from cream through orange to deep pink elsewhere, but are consistently deep pink here at Race Rocks. The lumps, when the polyps have withdrawn, slightly resemble raspberries, which belong to the genus Rubus; hence the specific name rubiformis. Extended, the individual polyps stick out about 5mm beyond the lump to which they belong.   Filmed by Jean-Olivier Dalphond and Damien Guihen on a sunny day at Race Rocks.


Gersemia rubiformis – a soft coral found underwater at Race Rocks. Usually it is found at the depth of 8 to 10 meters with an amazing variety of many other invertebrates. Here, no invertebrate is found growing on its own, they always occur in association with other invertebrates.

Gersemia occurs in fairly big pink patches in rather greater depths in the ocean but there are some small patches of it along the North cliff of Race Rocks. The lumpy colonies it forms usually are 10 to 15 cm in diameter.

Gersemia grows at the shallow depth because of the availability of nutrients there. Emerging from the walls are small pale pink polyps

Extended, the individual polyps stick out about 5 mm beyond the lump to which they belong. These polyps have small tentacles at the end. Each polyp has 8 of them, each with delicate branches which are able to catch masses of plankton for food. The vertical structure of the colony allows the polyps to be filter feeders and strain out plankton and other drifting organisms from the water column.

Embedded within the body wall of the polyp are millions of microscopic, photosynthetic organisms, known as zooxanthellae. They live symbiotically, provide food and fuel and absorb many of the waste products of the polyp. Without the zooxanthellae, the corals could not exist. It is the zooxanthellae that contains necessary chemicals for the adequate production of calcium carbonate, for reef forming types of corals. However Gersemia does not have a completely calcified skeleton, like that of reef-building corals of warmer seas. Zooxanthellae are also responsible for providing much of the colour in corals, which usually range from cream through orange to deep pink elsewhere, but are consistently deep pink in Race Rocks.
CLASSIFICATION:
Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Alcyonacea
Family: Nephtheidae
Genus: Gersemia
Species: rubiformis
Common name: Sea Strawberry

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. Ania Pawlicka——- PC yr 27, 2001