River shark is the common name for a southeast Asian river fish in the catfish family (not a shark). It is farm raised in Vietnam and sold in the U.S. under the name SWAI, and in Europe under the name panga. It is an inexpensive. mild, flaky, white fish that can be broiled, grilled, or fried. I have not eaten any yet but have heard mixed comments. There are numerous posts on the internet warning about health issues related to it. The claims are that the fish are bottom feeders and will eat almost anything. These posts further claim that they are essentially fed garbage. Farm raised catfish in the U.S. are channel catfish that are fed commercial feed that floats. Because it is less expensive it is possible that some restaurants are serving SWAI and simply labeling it as catfish leading customers to assume that it is U.S. farm raised catfish. I have not reached an opinion. You will have to decide for yourself. I post this because I only recently heard of the fish, and noted them in the seafood freezer section of my local Wal-Mart.