ITV4 Prehistoric River Monsters Catch up on the ITV Hub Jeremy Wade searches the world for legendary and flesh-eating freshwater fish. 2 episodes available to watch Share this programme: Copied to clipboard Share on Facebook Share on Twitter Copy link to share Series 1 Latest 3. Heavyweight Killers Sun Sunday 23 May 6.10am Jeremy Wade links living fish with the long-lost worlds of the prehistoric monsters. 2. Alien Sharks Sat Saturday 29 May 7.25am Jeremy is on the trail of alien-like super sharks, including the lethal buzzsaw killer.