Tag Archives: plankton

Pyramimonas sp. The Race Rocks Taxonomy

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pyrampool

On the east side of the island is the largest pool with Pyramimonas.

Pyramimonas is a green micro-algae, that is a type of phytoplankton.

Phytoplankton refers to the autotrophic component of the plankton that drifts in the water column.

pyram2

Samples taken from the green water in the upper tidepools

greenalgae

Here it is photographed at 400X under the microscope.

Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high numbers, their presence may appear as discoloration of the water (the color of which may vary with the phytoplankton present). This is certainly the case in the high intertidal tide pools at Race Rocks

In the high intertidal areas of Race Rocks, there are tidepools with wide fluctuations of abiotic factors. The organisms inhabiting these pools are well adapted to these extremes. Garry talks to a biology class about some of the variables influencing these high tide pools, and the flagellated green algae living within them.

The intense green color of the pools, swirly coloration of the water and a frothy covering early in the day indicate high photosynthetic capability. These plankton have an interesting response to changing salinity referred to in the video above.

Phytoplankton, like other plants, obtain energy through photosynthesis, and so must live in the well-lit surface layer (termed the euphotic zone) of an ocean, sea, or lake. Through photosynthesis, phytoplankton (and terrestrial plants) are responsible for much of the oxygen present in the Earth’s atmosphere.

pyramdiagPhytoplankton is consumed by microscopic animals called zooplankton (these are the second level in the food chain).
Zooplankton is consumed by Crustaceans (the third level in the food chain).
Fish that eat crustaceans could constitute the fourth trophic level, while seals consuming the fishes are the fifth.
A major reference work on this species may be found at :http://megasun.bch.umontreal.ca/protists/pyram/appearance.html

Domain:  Eukarya
Kingdom:  Protoctista
Division:  Chlorophyta
Class:  Prasinophyceae
Order:  Pyramimonadales
Family:  Pyramimomonadacea

Genus Pyramidomonas or Pyramimonas
Species unspecified

Photos below by Garry FLetcher of Laura Verhegge’s class.
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. Oct.2005Astrid Raquel Argueta PC yr 31

 

Coscinodiscus radiatus, Centric Diatom

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coscinpattern1

Pictures taken in lab by PC students from a water sample from Race Rocks

 

coscino Scientific classification
Kingdom: Chromalveolata
Phylum: Heterokontophyta
Subphylum: Bacillariophyceae
Class: Coscinodiscophyceae
Order: Coscinodiscales

Family: Coscinodiscaceae Kützing, 1844
Genus: Coscinodiscus Ehrenberg, 1839
Species: radiatus?

Coscinodiscus radiatus

coscinpattern

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

 

Tigriopus californicus: Harpacticoid–The Race Rocks Taxonomy

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We frequently find abundant populations of Harpacticoids in the high tidepools number 10, 7 and 2 at Race Rocks

Populations can fluctuate widely through the seasons.. Since pool 7 is at the highest elevation, it may not receive new inputs of seawater unless there is a wind from the West. In the summer, with no rain, and with elevated temperatures, this shallow pool will develop salt crystals. At that time, the only population of Tigriopus californicus is in pool 2 which is deeper and shaded, and in pool 10 which is small but shaded. Later on, in October, pool 7 may have an abundant population concentrated along the vertical walls of the pool. In this photo, The photo above was taken on a compound microscope at 10 power, but it has been enlarged considerably by photomicrography

In this photo Gerald has scooped up a sample from pool 10,where they are visible to the naked eye as small moving reddish dots.

 

 

 

Research done on this organism by the student T.C. Merchant at the Hopkins Marine Station of Stanford University in 1977, refers to this unique osmoregulatory adaptation for this Euryhaline environment.

“Abstract: Tigriopus californicus exhibit a unique osmoregulatory behavior which is highly adaptive in the high splash pool habitat. They conform osmotically in intermediate salinities and regulate hypo and hyper osmotically in high and low salinities respectively. Gut fluid appears to remain isosmotic with the environment. Evidence is presented to suggest the gut may be a regulatory surface in Tigriopus. The range of osmoconformance depends on the length of acclimation to a given salinity. O2 consumption in Tigriopus is high in low salinities decreasing as salinity rises. Metabolism appears not to change significantly over the conforming range 35 to 60 0/00″

Other interesting research on this organism has been on its Phylogeny. Research done in southern latitudes on Tigriopus revealed one of the highest levels of mitochondrial DNA differentiation ever reported among conspecific populations. S.Edmands ( Molecular Ecology,Volume 10 Page 1743  – July 2001) showed that populations from Puget Sound northward had significantly reduced levels of within-population variation based on cytochrome oxidase I sequences. These patterns are hypothesized to result from the contraction and expansion of populations driven by recent ice ages.

The Pesticide Action Network North America.lists extensive results of toxicity studies with Pesticides using Tigriopus californicus.

Dr. Maarten Voordouw working with Dr.Brad Anholt of the University of Victoria has researched the evolution of Sex ratios in Tigriopus californicus. He found there to be a variation in offspring sex ratio larger than the binomial expectation, and that females produce male-biased clutches at higher temperatures. The trait is heritable and is transmitted primarily through the paternal line. http://web.uvic.ca/~banholt/anhlabsite/tigs.html

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.   G.Fletcher

 

Plankton Lab

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BACKGROUND: Microscopic plankton can be can be collected in a way that allows us to determine densities of the organisms, and therefore compare different pelagic environments. We have already seen how plankton populations can vary from part of the ocean to another. In order to quantify plankton, the following method is suggested. You are urged to come up with your own research problem concerning plankton populations and then proceed to use the following techniques to investigate. Although this lab refers to Pedder Bay on Vancouver Island,, It could be modified to suit any location.

PROCEDURE:

In order to determine densities of organisms, we first have to know the volume of the water from which the sample is taken.

  • You will use a plankton net with a small propellor driven counting log to measure distance travelled in the water that is sampled. To calibrate the log, measure off a distance on the docks, read the dial at the beginning of the trial, drag it through the water the length of the measured section, and the difference in the reading at the end of your tow will be the length of your cylinder of water.
  • Now calculate how many counts on the dial there are per meter.
  • Divide the number of counts per meter into the number of counts through the distance you drag the net for your sample. This gives you a number of meters in length for the sample cylinder.
  • Measure the diameter of the net opening and now calculate the volume of sample taken from the open ocean. The formula for volume of a cylinder is V=(pi X radius squared) X h(meters)

 What is in The sample?

  • Note the total volume of the sample taken. Then remove a representative subsample of 1 ml.
  • Place the 1ml sample in a slide with a measured viewing chamber. Count numbers of individual species in representative quadrats. Obtain the average, and multiply this number by the total number of quadrats available.

 Density determination.

  • .Now calculate the density of the individual species in the sample . i.e. number per cubic cm. then per cubic meter.
  • Calculate the number for a larger area e.g. Pedder Bay ! Hint treat it as a segment of a cone for volume determinations, use a marine chart to determine the measurements of the bay..

Micro-photographs of plankton from Pedder Bay:

Pedder Bay frequently has blooms of Mesodinium rubrum. This organism turns the bay a deep wine colour . It is not a poisonous red tide, but we have noticed that when it is pumped up into seawater tanks, it will easily smother some of the filter feeders such as sponges. Blooms often coincide with nutrient loading followed by a period of sunny weather.