Sampling in
Field
In order to obtain live
specimens of tardigrades you will need to go into
the field and collect samples from various
locations. Record the date, time, and location,
including type of tree, for each sample you
collect. The greater the variety of locations you
take your samples from the higher the potential for
different types of water bears. Collect samples of
moss and lichens from tress and rooftops, being
carefully not to harm any of the vegetation (Please
use extreme caution when collecting from high
places.) Place the samples in separate paper sacs,
making sure to label each sac with the appropriate
collection data. These can then be stored in a dry
place for an unlimited amount of
time.
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Rehydration and
Extraction
After returning to the lab, the
animals can be rehydrated and isolated from other
debris. Being careful not to mix samples, place
each half of each sample (saving the other half) in
a separate dish and add enough water to cover all
of the collected material. (The water should be
spring water or tap water that has been in an open
dish for 24 hours, allowing for evaporation of the
chlorine.) The sample should soak for at least 3
hours and up to 24 hours. After the animals have
been rehydrated, they can be seen by examining a
small portion of the debris under a dissecting
microscope. Isolate the tardigrades by placing them
in a small culture dish with water, a very small
amount of debris, and food (rotifers and nematodes
which can be found in your original
sample).
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Culturing
Water bears can be maintained in
a culture dish for a number of weeks. Maintaining a
few key elements will provide an appropriate
habitat for tardigrades. First they must have
enough water to adequately cover them. Every 3-5
days most of the water should be taken out and
clean water should be added. The other key element
is providing them with enough food. Add rotifers
and nematodes as the are eaten. Also keeping a
loose cover over the dish helps keep unwanted
debris out and helps slow evaporation.
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LM/SEM Microscopy
Preparation
Once you have isolated a number
of tardigrades you will want to take a closer look
at them under a compound light microscope (LM).
First they must be slowed down. Placing them in
anoxybiosis, a death like state when no oxygen is
present, is the best way to do this. Put a number
of tardigrades into a small vial, fill the vial
with water, and then seal it. After a few hours
your animals should be in "dead man's float", a
temporary state. They will appear bloated and
motionless. A specimen can then be placed on a
slide and covered with a cover slip. You will want
to use Vaseline or a similar substance on the
corners of the cover slip to keep from squishing
the animal. Now examine the animal and make a
detailed drawing. When you are finished the animal
can be returned to a culture dish, where it will
return to its original state.
You are know ready to identify
your water bear on the web. Click here to access
the Taxonomic
Key.
Protocol for preparation using a
scanning electron microscope (SEM) are stilled
being refined. If you have access to an SEM please
contact
us and we will provide
you with further instruction.
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Mailing
Samples
If you have found a sample you
would like to mail to us here are a few
guidelines.
Packaging - place at least two
handfuls of your sample in a labeled paper bag. It
can then be mailed in a padded envelope or small
box. Include a short letter indicated what species
you have and why. Send package second day mail.
Address to:
SDP Dr. Susie Balser
Dept. of Biology
Illinois Wesleyan University
PO Box 2900
Bloomington, IL 61702-2900
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