Yes. Rawas as it is known in Marathi/Hindi is a sea fish.
salmon
I'm not sure what you mean by a freshwater salmon exactly, but the fish commonly called a sea trout is a type of perch and completely unrelated to salmon.
No, freshwater fish must be kept in freshwater and saltwater fish must be kept in saltwater. The one exception (that I know of) in nature is salmon which migrate from where they were born (freshwater) to the ocean and then back to where they were born again to breed.
One of the most common fish that can live in both salt and fresh water is a salmon:)
Fresh water fish. They are mostly found in northern United States. They are typically found in streams.
because saltwater fish must be live in saltwater
Some fish are salt tolerant and live in salt water (the sea) e.g. Tuna, Angelfish, lion fish, Ocean Trout, etc. Some fish are adapted to live in fresh water e.g. Brook Trout, Brown Trout, Rainbow Trout, Talapia, Catfish, Guppies, Mollies etc. Some fish can live in both sea water and fresh water e.g Salmon, eels etc.
saltwater
They are Saltwater fish.
Saltwater Fish adjust to salt/water loss by continuously drinking the saltwater. Then they must rid extra salt
the Indian name is 'SURMAI' the Indian name is 'SURMAI'
Saltwater fish are hypoosmotic.