4879
The Freshwater Lionfish Batrachomoeus trispinosus is a most interesting fish that can be kept in the brackish water aquarium. These unusual fish are found in the muddy bottoms of mangrove estuaries and coastal waters. It is actually more of a marine fish, but because in nature it spends a good deal of time where salt waters are mixed with fresh, it is more adaptable to lower salinity levels than other marine animals.
http://animal-world.com/encyclo/fresh/miscellaneous/FreshwaterLionfish.php