THIS IS LEGITIMATE!! It is extremely rare and unpractical in a confined environment. It only exists on 1 lake in the entire world! I dont have much information on it as their have been very few studies done on it. If your interested in freshwater sponges though they are native to North America and are commonly kept in aquariums heres a few pics http://www.fishlore.com/fishforum/freshwater-substrates-gravel-sand/42025-live-coral-freshwater-
Unfortunately, there are no known freshwater coral species. True corals (Class: Anthozoa) only exist in marine conditions. There are a few organisms that vaguely resemble coralline structures in freshwater. These are, for the most part, Bryozoans. Colonial bryozoan structures have a severely limited niche in FW. Leading to the logical supposition that their demands are highly restrictive to the possibility of maintaining colonies in an aquarium setup.
Stromatolites are another "coral-like" structure that, while predominantly found in saline conditions, can occur in freshwater. They are formed by microorganisms, predominantly cyanobacteria.
I have seen them in the Coahuilan desert and in Laguna Bacalar. While not all that impressive, are kind of interesting. Again, not something you could probably grow in your aquarium. Also if you could it would be rather boring, as they slowly form over thousands of years.
THIS IS LEGITIMATE!! It is extremely rare and unpractical in a confined environment. It only exists on 1 lake in the entire world! I dont have much information on it as their have been very few studies done on it. If your interested in freshwater sponges though they are native to North America and are commonly kept in aquariums heres a few pics http://www.fishlore.com/fishforum/freshwater-substrates-gravel-sand/42025-live-coral-freshwater-
