Several Different varients of fish (looking very similar) with one set of common names, try
Salmontail catfish
Shark catfish
Silver shark (sometimes)
forktailed catfish (australia)
nb the australian version can be kept either tropical or brakish the others while starting off as tropical need brakish before adulthood
HTH
Andrew
OOps forgot to mention depending on species expect a size of 1-3 feet
