Fresh water- Rivers
Marine water-Oceans
Brackish water-Lagoons
Not necessarily. It can be fresh, brackish, or marine.
An estuary is the area between freshwater biomes and marine biomes. The waters are brackish and have some of the same characteristics of each biome.
Flounders are saltwater fish, some can be kept temporarily in brackish water.
B. Hartley has written: 'A check-list of the freshwater, brackish and marine diatoms of the British Isles and adjoining coastal waters'
Freshwater ecosystems contain the least amount of saltwater compared to other aquatic ecosystems, such as marine and brackish water ecosystems. Examples of freshwater ecosystems include rivers, lakes, ponds, and streams.
Tropical and brackish are not mutually exclusive. Tropical means warm, and brackish means somewhat salty. Many brackish fish ARE tropical, and many tropical fish are brackish. You can keep tropical brackish fish with other tropical brackish fish, if they have the same temperment and will not harm or eat eachother. You can keep some brackish fish with some freshwater tropicals, and similarly you can keep some brackish fish with some marine tropicals. There are no wide open set of principles for brackish fish compatability beyond those that I have just illustrated.
Marine
It becomes what is know as brackish. An example of brackish water is the Chesapeake Bay, fresh water enters at the top of the bay from the Susquehanna as well as about 100 other streams and rivers. The bay then opens into the Atlantic Ocean. The Chesapeake is tidal, but is also constantly being fed with fresh water.
Paramecium uses the processes of endocytosis and exocytosis. Paramecia are single-celled organisms that can be found in freshwater, brackish and marine environments. They grow in big numbers in stagnant basins and ponds.
A marine amphibian is a creature that lives in brackish water. Marine amphibians can be newts and salamanders amongst many others.
I think marine aquariums are saltwater unlike freshwater that do not have saltwater
Roifers, a zooplankton, help sustain a microscopic community that supports small fish and crustaceans, and allow them to eat and grow. They are primarily freshwater or brackish water organisms, and are not natural prey for marine animals.