the three types of symbiosis are: mutualism, commensalism, and parasitism. Parasitism is when one is helped one is harmed, commensalism is when one is helped and one isn't bothered, and mutualism is when all organisms are benefited. Did I help?
At the end of the winter they are most numerous in fresh water. they will cover surface of aquatic plants or poles and wooden borders of ponds. If you like to study them you can scrape the brown growth with a flat piece of plastic. you can also use a sponge. for the free living (plankton) species fine mesh plankton net is very useful.
