Hydra viridissima

Hydra viridissima also known as the green hydra, is a species of hydra found in North America. It is found in still waters from early Spring to late Fall. The characteristic green colour come from cells of the unicellular alga Chlorella within the cells of the gastrodermis.

When disturbed it retracts to a small green BLOB which is easily overlooked. Gently sweeping through a clean weedy pond and allowing the collected water and leaves to stand in a jar will often reveal a Hydra emerging after only a few minutes. (See: poetry.)

Hydra viridissima