This animation demonstrates
how we took water from the different beakers with the dropper
and dropped about 3-4 drops of water onto the daphnia. We wound
up not using the VERY cold water because it was too cold for the
fish to survive in, and by the time we got around to testing the
daphnia's heart rate in the VERY cold water, most of the daphnia
had died in their container (see error in Analytic Essay for more
detail on why we could not test using the VERY cold water)!