River Monsters, STV, 8pm
ON a volcanic island in the Pacific Ring of Fire, an ancient fishing community is being terrorised by something in the water that has left behind a trail of bloodied victims. With a collective knowledge built up over centuries, these fishermen thought they knew everything in these waters – until now. The only clue they have to the attacker’s identity are the large puncture wounds it has left behind. Here, angling detective Jeremy Wade journeys to this land of fire and folklore to put himself to the ultimate test.

The Big Soap Quiz: Coronation Street v Emmerdale, STV, 9pm
IN the soap ratings war, ITV’s old favourites Coronation Street and Emmerdale have long been happy bedfellows. However, when it comes to contests, team members from the Dales and Weatherfield rarely take prisoners (unlike Pat Phelan). Here, Mark Charnock, better known as Emmerdale’s lovably eccentric Marlon Dingle, and Jack P Shepherd, aka Corrie’s bad boy David Platt, return to settle a score and lead their teams. Overseeing the latest round of soap-related head scratchers is Stephen Mulhern.

Graham Norton’s Good Guest Guide, BBC 1, 10.35pm
THE host presents his very own guide on how to be a “good guest” with a set of easy-to-remember rules for any star thinking about appearing on his chat show. Graham uses classic clips from his back catalogue featuring the world’s biggest stars to illustrate his advice. He also hears from personalities including Ricky Gervais, Miriam Margolyes and Julie Walters on how they faced the challenge.

Costa Del Celebrity, Channel 5, 8pm
ANNE Diamond reunites with her old breakfast telly presenting partner Nick Owen and, together with chef Ainsley Harriott, reality TV star Christine Hamilton and actress Vicki Michelle, they travel to Spain to sample life on the Costa Blanca.