Recent British Foraminifera of The Channel

2011-09-09T02:45:00.000-07:00

The Two Images from Toaday Radiolaria from Barbados 9/9/11

A Successful Victorian Method of Mounting Radiolaria.

2011-04-13T01:13:00.000-07:00

An Old Method of Mounting Radiolaria

Sometimes we use our own methods of mounting things that are perfectly satisfactory but occasionally when reading through old literature from the Victorian era we chance upon a method that really is excellent and much better than what we have. This is a description of just such a method from that age, which is equally suitable for use in dry mounting as in Canada Balsam.

Is begins with having a sieved washed sample of Radiolaria that has first been washed in acid and looks clean and bright in good light, before mounting.

Preparation is as with most things the key to success. Quality 3X1” glass slides need to be well washed and quality Gum Tragacanth as well as a ringing table is required.

Mountng in Resins such as Canada Balsam or Eukit.

The Gum Tragacanth solution must first be prepared . I use the lid of the gum jar as a painters pallet and add one very small portion of gum to a large pool of distilled water on the lid. When the gum is fully dissolved there must be no blobs of mucilage visible. If there are any blobs, use a pipette to suck them up and add more water, until nothing is visible in the fluid.

The clean 3X1” slide is placed on the ringing table and a little paintbrush is used to run a circular pool of gum water onto the centre of a rotating glass slide. Check that the circular disk of gum/water is stable, sometimes it prefers to run off into pools. Then perhaps the suface is contaminated and an alcoholic wipe might help.When the liquid is correct, dry it off with gentle heat until quite dry. One should be able to see a dried up but complete feint disk of dry gum . If it is too white and prominent, wash it off and try again with less gum or more water. Remember, that the dried up disk of gum will become the same diameter as the completed strew of Radiolaria.

Then make sure the slide is cool . Here a cold plate from a fridge might help, and breath on it. Ones breath should condense on the glass in droplets but the disk of gum will become slightly liquid, as it absorbs moisture. Then pour the shells from a Petri dish onto the central disk quite thickly and then invert the slide smartly over the Petri dish so that most of the loose shells return to the dish. Tap the glass to make them fall. Then use the warmth of a lamp to dry the thing off fully and again invert the slide over the Petri dish so that the shells that landed on the liquefied gum remain, but those that landed on damp glass now fall, having dried out. One should now be looking a a clean disc of Radiolaria surrounded by clear glass. Make sure that the whole slide is dry by heating under a lamp.

Then a resin like Canada Balsam thinned with a little Xylene is dropped on the middle to help expel the air from the shells. Then place a drop of thicker Balsam or other resin over the shells and lower a cover slip.

This may seem to be quite a performance for a tiny circle of Radiolaria, but it will be worth the effort. The resin may then be dried off with heat in the usual way, and the slide labelled.

Dry Mounting

Dry Mounts may be constructed in a similar manner but first an aluminium ring must be cemented to the glass and a black background must be laid and dried . More care is needed in any heating or the paint may be damaged. The circle of gum-water can then be laid using the ringing table. When this is successful the same procedures can be followed but without the Canada Balsam or other resin of course. This same system can also be used to renovate a very old slide that has through the ravages of time become thoroughly unsuitable for use. The method itself was I know learned from a very old book but I am afraid that I have long forgotten the reference or the original author of the idea.

Image to follow next weekend, hopefully BD

Two Species of Lagena

2010-11-09T02:40:00.000-08:00

At the moment I am trying to complete an illustrated booklet on the Foraminifera from my digital pictures and I have just been distracted by these two species of lagena. As usual with only the resouurces of an amateur I am not too sure about this pair. As usual Cushman always comes up with something but sadly the illustrations are never so good for certainty. Please click on the image for a larger image. Any help would be appreciated BD.

A look at a 15 cm cube of chalk

2010-08-11T01:55:00.000-07:00

This is a photo of an average sized species of Foraminifera sieved from chalk at Ballard Down. A 0.01 mm grid has been superimposed on the image in order to enable measurements to be made.The thickness can be estimated from the quite globular chambers.Effectively the organism is actually somewhat wedge shaped;thicker at the top than the bottom.

Please click once on the image in order to enlarge it.

This entry is an effort to estimate the number of Foraminifera tests in a 15 cm cube of chalk from Ballard Down Dorset Uk.

I have always thought that such efforts were rather a waste of time, because there are so many variables when dealing with fossil material 95million years old. Never the less its really surprising what sort of a number one can come up with, but it is just these figures no matter how inaccurate, that engage and surprise the general public.How do we find an average when there are so many eroded tests to sample ?

I have just taken a typical surviving test mounted in a canada balsam strew that is neither too small nor too large by observation. The initial measurements were taken with a Beck eyepiece graticule graduated in parts of a mm. I shrank and expanded the image until it was exact according to my record through the microscope.
Since the chambers of the test are quite globular, I measured the radii of each chamber and calculated the volume of each, using the formula (Radius cubed times PI times 4/3) ; the formula for the volume of a single globe. The results were then added together. My selected "average" test made 0.00044107 cu mm which is pretty small .

This was then divided into the volume of the 15cm block cube which is hopefully 3,375,000 cubic mm. The result is rather nicely 7,651,846,645 which is fascinatingly enough very nearly the human population on Earth not so long ago. I think we are currently way past this figure and well over the 8 billion. This means that the calculation for the whole of Ballard Down would need a considerable amount of paper, and my old computer would certainly blow a fuse in the process.
When I consider the effect of potential inaccuracies on this figure it can more probably become greater than smaller.

I fully appreciate that numerous other and perhaps better methods can be used to arrive at a figure. I tried several alternatives but came back to the above with all its faults. BD.

A Question concerning the point of the needle answered

2010-02-14T01:44:00.000-08:00

On 14 February 2010 09:32, wrote:
This refers to an article of mine in Micscape UK QV on a mounted needle.

Hi ............
Yes I knew it!!!!!!!!.............. I should have spent more time writing about the point.

that was the really the point of the aticle I suppose.!!!................
I have to write that at first I could not find a tube that was 1mm external so I used 1.5mm diam. and had to shape the point by rotating it when it just protruded from my mark one version . I used a combination of a fine triangular file and very fine sandpaper to make a blunt point of about 0.3mm diam. at the end but the very end was flat and burnished flat and then painted with Matt black.
The relatively. large forams like Elphidium I glued on the round end with water based Gum tragacanth so that any part of the periphery could be imaged. by rotation .====Then I decided that a flat platform was also a good stage for angular shots of apertures .so I filed one side flat to create a flat stage 2mm long which bit into the end of the cylinder to a width of 0.3mm. I had to buy a brass vernier measure .
When I found my 1mm external hollow brass tube in Holland the diameter of the insert was 0.3mm and that was the right size without treatment except when I wanted the inclined stage. All the measurements were based on my wanting to look at the Foraminifera tests. and in particular those of +_ 500um diam.

So briefly Gumming with Gum Tragacanth on the end of the 0.3mm insert rod is how I now do it.

Centralisation on the end so would be trial and error whilst under the microscope as the tests are drying off..

Its up to you folk to develop it. I can see that some with a large(ThicK) mechanical finger on thir stage (ie the Clip)may need another slide glued underneath but that is not a problem. Also for reflected light only then a layer of paint underneath might look neater and avoid little glares!.

Also Please read info on the supply of 1mm hollow tubes
NOTE for integration into the text or at the end.

A SUPPLY OF 1MM HOLLOW BRASS TUBES.
At first I could not find any tube less than 1.5mm in diameter in the
UK. I had to use thicker glass up to 1.5mm but it
was much more difficut to cut neatly.

Even on line scanning on US sites, I found nothing; they still seem to
be using imperial measure anyway. Then I began to look at the EU and
sure enough there was the 1mm I was looking for on a Dutch site for
hobbyists.

http://www.plasticmodelbouw.nl/contact

The internal hole was 0.3mm which was just right. A pack of several
tubes was less than £10 with postage and took only 3 days BD.
Best wishes Brian Darnton. Swanage UK

An Introduction To Dorset Foraminifera

2010-02-07T08:25:00.000-08:00

Recent Foraminifera of the Dorset Shores.
These delightful microscopic shells grace the tidal waters of Dorset. They are not true shells however but are more closely related to the antediluvian Amoeba of our school text books. In order to protect themselves from the multitude of hungry creatures in the sea, they have simply developed a spiral shell like structure called a test, though the smaller ones prefer the simplicity of an urn shape. In the open ocean, the more globular species float with the plankton and it is these free spirits that form deep deposits on the sea bed. Given a few million years of pressure they will become chalk, as at Ballard Down. They are mainly constructed from some form of crystalline chalk and others look externally almost like porcelain.
In the great lagoons of Poole Harbour they enjoy the muddy less-salty water by means of an adaptation. With a shortage of the minerals of the open sea, they create a bag of chitin-like material and bond silt and sand particles onto this to make their tests. This can be seen in the illustrations on the top row, these are called arenaceous tests and are often very beautiful indeed.
Each species has a preferred level of saltiness and temperature, so seen together they are useful environmental indicators. At Swanage and Weymouth the mortalities are washed up at the most westerly edge of the bays with the sea-coal fragments. This alternate black and white banding is a good clue to their location. In the harbours and lagoons like The Fleet they are to be found around the edges near the high tide marks. as well as embedded in the mud itself.
The Foraminifera of warmer waters can be larger than one millimetre but most of the Dorset ones are from a tenth to a half of a millimetre in diameter and provided they are well illuminated they can be seen with a good hand lens or a simple microscope.
This phylum of single celled members of the Protista are just a tip of the iceberg sample of what exists in the seas around our world, when examined with a microscope B.D.

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2009-11-05T01:41:00.000-08:00

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2009-11-05T01:33:00.000-08:00

Arenaceos Foraminifera of Dorset

2009-11-01T01:46:00.000-07:00

Illustrations of the Foraminifera in West Dorset UK

2009-10-30T06:37:00.000-07:00

QUAD IN BBC BASIC SEE PREVIOUS NOTES.

2009-02-02T13:22:00.000-08:00

Geometry of the Diatom Frustule on BBC BASIC

2009-02-02T08:11:00.000-08:00

Some Time ago I wrote a little article on playing with Diatom shapes on THE BASIC computer programmes. It was more intended to be a little Christmas fun for microscopists at a time when I was looking at fractals..
The work was published on MICSCAPE UK and is still in their data base under my name (B.Darnton). Several people had fun writing in both BBC BASIC and QBASIC using the relevent language. Recently a friend drew my attention to the fact that a new BBC BASIC is available at http://www.rtrussell.co.uk/ . This will run within MS WINDOWS. A free download of a trial version can be accessed as well as the full programme which of course needs a fee. There is much advice on how to use it under HELP but one of the improved features is the automatic colour coding of words so that for example line numbers appear in one colour and words of command in orange etc. The result is that mistakes like incorrect case use, or bad spelling, stand out in the wrong colour which is very useful when writing the programmes.
I hope to be able to upload both the images produced, as well as images of the programmes. These will not copy in text form :I left them as an image in order to demonstrate the colour code effect. These programmes will run on the free download from R.T.Russell and unless developed do not require the ull programme.

NOTE If you would like to watch the development of the running programmes then insert a line

WAIT 10 anywere in the loop before the NEXT line.

A New Microscope

2008-11-15T11:51:00.000-08:00

My new microscope, which is a Henry Crouch, was recently purchased at the excellent camera shop of Mr Palmer of Bridport Dorset ( Near the bus station). I have improved the fine focus with a new adjustment and I have purchased an alternative low power objective lens of Voigtlaender & sohn A G 38mm (Euryscop), for my little Foraminiferids. The Boxed microscope also contained the standard pair of objective lenses in brass cylinders with data. The Number of the microscope is 8801 and I wonder if anyone has a book containing data such as the age of this instrument. I really would be obliged for this information. brian.darnton@googlemail.com

Slide of Poole Foraminifera with labelled grid of 12

2008-06-17T10:48:00.000-07:00

The slide was created on a standard 3 inch by 1 inch glass slide.
The artwork was first completed on a computer and the printout was reduced by photography with a 35mm camera using litho-film. The 19mm round film was gummed to a slide using uv cured glass bond after treatment . The coverslip was also stuck with glass bond.
The main species are included from the harbours` southern shore.

The Fleet Lagoon near Weymouth Dorset U.K.

2008-04-18T08:17:00.001-07:00

This photo shows the shallowness of this part of the fleet. The image was taken at low tide.
Please click on the image for a larger version. The Light coloured deposits can be seen on the aerial maps of the area as seen on the web. Live Maps may be used by either searching or clicking. See link below.

http://maps.live.com/

The red dots outline the very rich and extensive deposition sites. The species found are very similar to those of the estuarine sites of Dorset like Poole Harbour, but the arenaceous types are less numerous than at Poole.
The Village of East Fleet with its literary connections and ancient churches is an enchanting place. There are fossil types here but floatation has been used to reject them.

This is a photo of the water surface during the last stage of floatation, using material from East Fleet. It is a rich collection.

A General Guide to the Deposition Zones of the Foraminifera.

2008-04-11T13:40:00.000-07:00

In the British Isles the tidal flows are from the SW Corner along the the South Coast. On the diagram this would be right to left, so the place to search is point B. This is valid for Swanage, Weymouth and Tor Bay. If the bays of the North East are examined then the flow is from the North Eastern corner of Scotland and on the diagram would be left to right and the site would be at A. This is valid for Scarborough and Filey. A quick look at the tide tables of ports either side of the bay in question, will soon determine direction if there is doubt. Of course few bays follow the exact symmetry of a diagram so a little common sense is required. Do not forget that blog images can be enlarged by a click of the mouse. In estuarine conditions like Poole Harbour,limited deposition zones can be identified by the concentration of shelly remains in the mud. Please see earlier posts. BD.

A glance at some of the non Arenaceous types at poole

2008-04-07T12:20:00.000-07:00

This list is just a snapshot and by no means a complete listing.

Another look at species at Poole

2008-04-07T12:07:00.000-07:00

These are some of the Arenaceous types, from the gastropod deposition site at Redland, Poole Harbour.

A deposition zone for Arenaceous types

2008-04-05T12:58:00.000-07:00

In the open sea, the deposition sites in sheltered bays are pretty obvious ( see early blogs)but within the estuarine conditions of Poole Harbour do these exist? These gastropod shells seem to collect along with shelly mud in the middle tide marks of the harbour and the sievings (0.1mm-0.9mm)from this material are quite rich in arenaceous as well as other foraminifera. I have washed and sieved out the shells so that identification is possible. They are somewhat larger than 10mm. Click on the image for an enlarged version.

A species of foraminifera that does not seem to belong here?

2008-03-20T08:29:00.000-07:00

NB Please click to enlarge most images BD

These are two images of a species that is found the year round in Swanage Bay U.K.at the deposition zone (see relevant post). The first upper image is from a test dry mounted. The lip is usually slightly more reflexed and the length is on average 300 microns though larger ones occur. It is not numerous but with each collection there are one or two tests. The lower image is from a test in Canada Balsam and in dark field illumination to reveal the hidden chambers. There is a large mega primary chamber and six or so in biserial formation. I can not find this in listings of recent Forams of the British Isles in the main text books. The only similar species is in the Brady plates Plate 75 fig 22 Siphogenerina raphanus in the Robert Wynn Jones version. The illustrated species comes from the Pacific Ocean. Since it does not seem to belong to the UK fauna , there is the possibility of it being fossil but I always float the washed and dried gatherings and fossils usually have some form of heavy inclusions. Since Swanage lies between Jurassic and Cretaceous rocks the fossil possibility I suppose exists. If anyone can point me towards a more correct name I would be obliged. For a larger picture please click on the image.

brian.darnton@googlemail.com

Dated March 2009

I have had no comments to date. but will add the folllowing information

Siphogenerina raphanus
After really long term searching I am more certain that species, which consistently turns up daily in floatings from
Swanage is part of our recent foram fauna of the Dorset Coast.

It is not listed by Murray in his 1971 Atlas nor by J.R. Haynes in his 1973 work on Cardigan Bay. The identification came
from the Robert Wynn-Jones Brady Plates revival of 1994 where there is an original image from the Brady Books on Plate 75 fig 21a &b and 22. There is no mention of the British Channel but later I found it in Cushmans Atlantic 1923 at least. Plate 42 fig14. Its a very poor drawing indeed but his text is helpful.

Generic Synonyms from Cushman.
Uvigerina, several refs to Sagrina as well as 3 references to Siphogenerina.
Some features:
Up to 1mm long. ---It begins life as a biserial test but half way becomes mono.-The costae are continuous not being broken at the sutures. There is a description of the flaring lip which I would call slightly reflexed. It is certainly distinctive enough not to be confused by S dimorpha although this near species has been recorded in the British Isles and Norway in a very positive manner.

The Southern Shore of Poole harbour

2007-10-09T11:40:00.000-07:00

This shoreline on the Southern shore of Poole Harbour is a very fruitful site for Foraminifera. Anchor mud as well as shore gatherings are equally rich in the summer months at least. The Photo is taken looking northwards from along the Redland Peninsula. The area is characterised by a graveyard of old hulks as pictured below

Foraminifera being scraped up with mud from the intertidal pools.

The mud will of course need to be passed through a 400 micron sieve to eliminate weed and then collected in a 100 micron sive for washing in clean water, before drying, cooling and the floatation process.

FORAMINIFERA IN CROSS CURRICULAR EDUCATION

2007-10-08T05:49:00.000-07:00

Digital image by Sue Fox of Kennedy School Warren Michigan U.S.A.

INFORMATION SHEET ON THE FORAMINIFERA

• Foraminifera are Biological indicators: The assemblage of species can indicate the effects and changes of temperature & salinity.
• There are millions of Foraminifera in the seas of the world, where they are deposited from inshore species and deeper sea deposits during rough weather.
• Although sometimes numerous, the deposition zones are usually restricted to the edge of the bays nearest the incoming tidal flow. i.e. The West end in South England ;The Northern end in the North East.
• Chalk cliffs and other exposures contain fossil Foraminifera.
• They are almost as primitive as the better known Amoeba, but grow a chalky shell called a test. Some species create an outer shell (Arenaceous) cemented from marine particles like fine sand or silt or biological remains like other Forams or sponge spicules.
• They live in sea water on the bottom, on weeds, rocks or mud. Others float in the open Sea as plankton.
• They can also be found rarely in brackish ponds over salt deposits as on the Austro-Hungarian border.
• They are very small being rarely more than 0.5mm in diameter, but some warm water species can grow up to an inch (Nummulites).
EDUCATIONAL .ASPECTS.

The study of Foraminifera could be an ideal component of the School Curriculum. It lends itself easily to cross-curricular development in the widest possible sense. The subject certainly impacts on Biology, Art, Mathematics, Geography and Geology. The Foraminifera are regarded as climate indicators, and faunal change may be significant in the future. Although Foraminifera figure in remote parts of higher education, limited US schools are beginning to take an interest in the subject.The Pioneer school is Kennedy Elementary (van Dyke Schools) Warren Michigan USA.

Art The empty tests or "shells" have considerable aesthetic appeal and are very diverse in shape, describing spirals from simple to compound as well a.s many other morphological developments. The natural colours and textures of the test vary considerably.
Mathematics. The treatment of statistically based biological counts of species in samples.Foraminifera shapes and forms provide interesting comparisons for geometric analysis and subsequent graphical representation.
Geography. The study of world wide distribution can lead to climate linked data. The components of a collection can indicate common climatic factors like temperatures and salinity.
Biology. Material from shore or deep water gatherings does not require to be killed or fixed, nor would their collection affect the environment in any significant manner. Investigation would be quite suitable for low magnification, low cost microscopes. The anatomy and physiology of foraminifera is quite varied and can be tackled in a simplistic or an in depth manner. The study of fossil tests is an essential part of more advanced Geology but also lends itself to the simplistic approach. Many teachers are unaware or their significance or even their existence.

Brian Darnton United Kingdom

Anchor mud as a means of foraminifera collection

2007-08-28T06:49:00.000-07:00

This is a picture of a Spade anchor being used to collect raw mud from Poole Harbour sites. The resultant material must then be washed through 500micron sieves to eliminate weed and then collected in a 100 micron sieve which holds the forams. If you need the finer types a 60 micron sieve is better but of course much slower.

Although anchor mud gathering is thought to be a system preferred by the very first sailing ships before elaborate dredges were inventd, its very suitable for the amateur as it does not need to be purchased. An anchor generally comes with the boat. The use of the anchor has considerably increased the numbers of inshore species in my collection.The Image was kindly taken by the owner and skipper of the good ship "More Hopeful" which is moored on the southern edge of Poole harbour.

Young test of Ammonia tepida

2007-06-09T03:15:00.000-07:00

This test is about 190 microns in diameter and was still attached to the parent from which it was derived by a tough strand of protoplasmic like material.
This demonstrates Summer reproduction with a large primary chamber of 55 microns followed by a smaller one of around 30 microns. It is not until the 8th chamber that the size becomes greater than the primary one.It has not yet been cleaned but it emerged from floatation in this condition and the strand broke during mounting.The test was mounted in old canada balsam. The slide is interesting in that it clearly shows the early test development which is often obscured by subsequent growth in adult tests.

Arenaceous Foraminifera of the Swanage Area

2007-06-07T13:20:00.000-07:00

Museum of Recent British Foraminifera

2007-06-05T05:37:00.001-07:00

A Slide of British Recent Foraminifera

2007-06-02T09:26:00.000-07:00

Victorian ideas on the Floatation of recent Foraminifera

2007-05-27T05:32:00.000-07:00

The gathered tests and sand or mud must first be washed in a 100 micron sieve with flowing water to remove salt. They must then be dried and cooled.

A whisky glass is 3/4 filled with cool tap water and the powdery material from the sieve is sprinkled onto the surface. The best foram tests will float and drift towards the edge of the glass. The silica and other debris will either sink or float in the middle of the glass. If the water level is reduced with a bulb pipette then the tests will be stranded around the edge of the glass where they can be picked up with a brush which can be washed out in a petri dish of pure water. A 1/2" wick of kitchen towel can be used to dry out the dish by micro-siphoning. The dried tests can be sieved for mounting.

The main Deposition Zone in Swanage Bay

2007-05-25T11:57:00.000-07:00

Empty tests *of the inshore Foraminifera are deposited on the beaches of the U.K. on the side of the bay from which the tidal stream flows. So on the South coast it`s on the most Westerly end of the bay. In Swanage the site is around the Public Hard near the Mowlem building. The tests have a similar density to the sea coal and together they provide a useful disinctive banding as in the picture. Detail will be revealed by clicking on the image. A flat plastic card is all that is required to scrape up the whiter parts in the banding. The mixture then needs to be washed in clean tap water to remove salt in a 100 micron sieve and then dried out by heat and cooled.Victorian type floatation may then be used to yield the better tests.
* Tests are the shelly remains of the Forams.

Below is a Plate of the more common Species at Swanage Bay.
Please click on the image for a view at greatest magnification.
The two most numerous species deposited during the whole year are
Elphidium crispum and Massilina secans q.v. below
Elphidium lives mainly on the seaweed and Massilina can be found in the numerous rock pools between stable stones.

Collecting in the Saltmarsh of Poole Harbour

2007-05-24T13:06:00.000-07:00

Collecting from the mud of a saltmarsh is a little trickier. little depressions where shelly remains lie is a good place to scrape. Near the high tide line there may be stranded pools. These areas particularly at Arne, are quite rich in a variety of uncommon Arenaceous types QV in laterPosts. Be on the look out for very soft muds that will not support walkers and are dangerous. The base of channels are generally the hardest areas for walking.