Fans of River Monsters know On Sunday night’s Mighty Rivers, host Jeremy Wade is searching for the endangered huchen or Danube salmon, a large species of freshwater fish in the salmon family.

1. Demon Fish - Jeremy Wade journeys up the Congo River in search of the ferocious Goliath Tiger Fish, but he will need the help of a local witch doctor to catch one. More info ...

4. Amazon Assassins - Legends tell of an evil spirit in a great fish in the depths of the Amazon - Jeremy Wade has encountered this creature before and is taking no chances this time. More info ...