There is only a single family of aquatic sponges in the U.S., Spongillidae. While 30 species are reported for the U.S., Ohio EPA has identified only 11, with another possible, but not yet found, in 7 genera.
The sponges are indicators of high water quality and are found in clean ponds, lakes, streams and rivers.
They are seldom noticed, and often confused with algae, because they are sometimes green due to their interaction with plants and algae, but they have a rough feel rather than the slimy, soft feel of algae.