From a water sample taken from Lake Cook in Alexandria, Virginia. This is the rear edge of the shell of a freshwater limpet, ~3mm long. When I checked him out under the microscope, he had a gang of vorticella living on his shell. Vorticella seem to install themselves on any hard surface they can find, whether animal, vegetable or mineral. I’ve seen hundreds attached to a cyclops – surely one of the most active animals of its size. I don’t know if the vorticella actually benefits from a relationship with the creatures it inhabits.
