Water Bears - Tardigrades

Tardigrades or water bears are said to be common creatures but after some fruitless searching in moss and lichen it was a delight to be given some "mucky water" from a neighbour's garden; water that had stood in a big plant pot and had accumulated some lichen and moss. In there were tens of bears. At first we watched them with a stereo microscope, using the highest magnification that the Prior could manage, which is x120. Sure enough - 4 pairs of stumpy legs. Several seemed to have mauve spots, several on each segment, but others were essentially colourless. Photography was not successful until I found a dead one on its back in the bottom of the petri dish. Using a fine pipette, I carefully transferred this to a microslide and that enabled me to take the following pictures, all using the video camera on the compound microscope. Estimated length of creature 0.2 mm.

x10 objective

x40 objective

x10 objective

Actually it wasn't dead and during the photography it began to stir into action again so it was transferred to petri dish where several others have been seen! Experiments with dark field illumination have been quite successful with the x10 objective.

Since these pictures were taken we have found a good source of tardigrades in moss on a concrete path in the garden. Soaking the moss in distilled water for a couple of hours and then gently squeezing some of the water out of the moss produced at least a dozen tardigrades, some colourless, some colourless except for a rusty-red patch roughly amidships and some "tartan" - i.e. with a pattern of dark mauve/red lines on all segments. Photographs with the video camera attached to the stereo microscope are disappointing because of the small size of these creatures.