The tardigrade reality show
Obviously, it might be ethically doubtful to remove an inhabited moss cushion
from its original position and to soak it in a petri dish in order to finally topple it
over until the tardigrades are falling out.
Furthermore, most biological tardigrade investigations will be performed on
tardigrades which are sliding helplessly on slippery glass surfaces like
microscope slides. Some brute amateurs and professional even tend to neglect
the iron rule of cold light. As a consequence many tardigrades are stewed incidentally.
Even if you generally neglect morals with respect to tiny organisms you should be aware
that natural tardigrade behaviour will be observed only under mild, tardigrade-friendly conditions.
As an example we would like to present a small video clip showing a tardigrade
which is crawling on its natural moss cushion and hiding in a small cavity
(filmed under cold light, 2 MB):
Compared to usual videos showing tardigrades in artificial environment
it becomes apparent that this tardigrade is not just struggling in order to grasp
a safe moss leaf but instead follows some reasonable course of action.
Of course we have no chance to understand the motivation behind the movement.
It might still be possible that the tardigrade is feeling uneasy because of
the relatively strong light which might imply rapid desiccation and thus danger
under natural conditions.
The video is slightly accelerated (by a factor of 2)
in order do cut down download time.
An interesting field microscope
Many microscope amateurs are routinely screening Ebay auctions in order to
get additional information on rare microscope equipment. In particular
small field microscopes
tend to be scarce and highly priced. The list of those collectible "cult" instruments
is not very long: Nikon Model H, Swift FM31, Swift M51, McArthur microscope, Hensoldt Tami
and Hensoldt Protami. Those instruments are quite interesting for the tardigrade enthusiast as well.
Of course the psychology behind this attitude is a mixture of reasonable motives and glamour motives,
i.e. to own a very portable thoroughly scientific instrument with a little bit
of James Bond glamour. And you might remember that even the rational and sober Sherlock Holmes
praised his tiny field microscope.
As a consequence of scarcity and collectors' avarice prices easily rise beyond the
1,000 US $ mark, in some cases even hit 5,000 US $.
But when keeping in mind the construction problems and the optical resolution powers
of those microscope dwarfs the prices are still acceptable - well, you just need to
be a little crazy, not extremely crazy.
First of all we would like to draw your attention towards the most famous stars in
this portable microscope heaven:
Here you will find a review of the classical Nikon Model H field microscope:
Nikon Model H Revisited
And furthermore there is a nice website by a collector of Nikon field microscopes:
Nikon Model H presentation by Gregory Guida
A free download version of the John S. Billings microscope collection
is available online as well (and, of course, also the Nikon Model H is included).
In the meantime a new star has risen to field microscope heaven and there are rumors that
it actually might be a serious competition for the yet unrivalled Nikon model H.
Just have a look at the photograph and caption below:
A remarkable, apparently mostly
unknown professional field microscope, at par with the Nikon Model H:
very sturdy compact build, almost everything made of solid metal, with an electrical
illumination well fitted into the stand and perfectly adapted to the special optical requirements,
a condenser with N.A. 1.2 (which will work with the oil immersion objective as well),
iris diaphragm, blue bulb-to-daylight colour conversion filter. The microscope can be
taken out of its pocket and it is immediately usable, you just have to switch on the light.
Even the coarse focus can rest in a pre-fixed position, so normally just a tiny
movement of the fine focus milled wheel will immediately provide a crisp image. Overall the basic
construction at first sight resembles the classical McArthur microscope but it appears
to boast some advantages over it, as it still allows an upright specimen position
and because all susceptible parts are sheltered by the stand.
The instrument shown here was fabricated in 1974 for the Chinese army and apparently has never
been used. We will discuss the optical perfomance in the next issues and show some
sample images as well - see you!
© Text, images and video clips by
Martin Mach (firstname.lastname@example.org).
Water Bear web base is a licensed and revised version of
the German language monthly magazine
Style and grammar amendments by native speakers are warmly welcomed.