I’ve spent a lot of my summer looking at the sorts of creatures that inhabit freshwater ponds and creeks. Of these, my favorite are the cyclops and the hydra. Cyclops look like tiny darting white dots to the naked eye, but the microscope reveals a lot of color and patterning in their bodies. I found this one darting around in the sample of water from a creek in the Brooklyn Botanical Garden. It was not alone; other cyclops swam around with it, along with a few dozen clam shrimps and many protozoa.
Earlier in the summer, I found this hydra completely by accident, attached to the branch of a freshwater plant. Since childhood I have been obsessed with hydras, but never had the opportunity to observe one before now. No larger than a centimeter or so in length, this one extends its tentacles into a drop of water in search of smaller creatures to eat. Looking at it under a scope gives us a chance to see the cells of its outer body and the anatomy of its gut; it also gives us a chance to compare its cells to the cells of the plant it’s connected to.
It strikes me as funny how many of these creatures I look at have their names taken out of mythology. Odysseus fought the cyclops, and of course, the Hydra, with its toxic breath and weakness to fire called to mind the fear the ancient world had of microbes and diseases, their seemingly magical ability to live through all but the most scathing cures. So that people discovering these critters as we awoke to the scientific revolution observed the strangeness of their forms and called to mind creatures from the distant human imagination.