Steve Bellion, 23, caught the giant reptile at Earlswood Lakes near Solihull last Friday.
It is believed the animal has been biting through anglers’ lines and preying on wildlife for about a decade.
The creature has been rehomed at West Midland Safari Park in Worcestershire where it is hoped it will mate with a male of the same species.
It is thought the North American animal was released by a private owner after becoming too big.
‘Special animal’
Anglers claim the reptile has escaped after being caught by lines on previous occasions.
The alligator snapping turtle, North America’s largest freshwater turtle, can weigh over 80kg (12.5 stone) and live to 160 years old.
Bob Lawrence, director of wildlife at West Midland Safari Park, said: “Thankfully alligator snapping turtles are a rarity in British waters – they can create havoc for native species.
“It’s great the turtle now has a safe home. She appears to be in good health, and as we also have a male of the same species, we will be checking compatibility to ascertain the possibility of mating.”
It is thought the creature pulled from Earlswood Lakes is about 80 years old.
British Waterways ecologist Paul Wilkinson said: “Although it is a shame that we are taking this special animal out of the wild, it is necessary to protect the natural balance.”