Pikes are also predator fish that can grow huge (usually up to 1.8m). In fact, pikes in their natural waterways are long favoured by anglers because they can put up a good fight. Pikes are also good seafood and have been eaten by man since forever.
One of the common pikes in aquariums is the Northern Pike. Usually for sale at four inch with a ducklike head, don't be surprised that they ultimately grow up into a monster.
Pikes are ok in freshwater aquariums when young, but when they grow up they need to be in brackwise water otherwise 'sudden death' will occur.