Depending upon the species of fish, they eat shrimps, crabs etc. detrius, dead animals, live and dead insects and their larvae, water plants including algae. The list goes on and on.
they can be dripped into brackish water tanks
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.
Brackish?
No they can't because sharks are saltwater fish and large mouth bass are fresh water fish.
Flounders are Saltwater Fish, some can be kept temporarily in brackish water.
probably not, marine fish are designed to osmoregulate at a very specific and unchanging salinity (usually a SG of 1.025) whereas brackish fish by nature are adaptable to anything from fresh water to fully marine but are usually situated around a SG of 1.008. odds are if you put a marine fish in brackish water it would die
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.
Saltwater fish as fish that live in water with a salinity of higher degree than brackish water, such as fish from the ocean. Clownfish (Nemo), Tangs (Dory), Tuna (Charlie) are commonly known saltwater fish.
YES! Bull sharks mainly stay in brackish waters. They have the ability to swim up the river. Bull sharks have been found at the end of the Mississippi river in the Northern Part of America.
Brackish water
The mixing of fresh water and saltwater is called brackwater or brackish water.
The short answer is all of them. The one you see for sale in aquarium store should be in brackish water, which is a mixture of ocean and fresh water. More like marsh water. If you see them in "Pet$mart" remind them that that puffer fish need to be in brackish water and not the same water that all the other fish are swimming in at the store. As far as I know, there is no variety of classic puffer fish that lives in pure fresh water.