A giant fish-eating worm with jaws twice the width of its body has been discovered hiding amongst coral and rocks in a Hull aquarium.
Staff at The Deep found the 1m-long (3.2ft) Bobbit worm as the rocks were about to be moved into a tank containing other fish.
Aquarist Seb Prajsner said: "It looked like something straight out of a science fiction movie."
The worms can grow up to 3m (9.8ft) in length and are up to 2cm (1in) wide.
It is believed it had hatched on the rocks and had gone unnoticed by staff.
Sliced in half
As they were about to transfer the coral to a major display tank, the worm shot out.
Armed with sharp teeth, the underwater predator is known to attack with such speeds that its prey is sometimes sliced in half and is among the longest worms in the world.
Colin Brown, chief executive at The Deep, said: "Thank goodness Seb discovered the potential menace before it caused more damage.
"The occasional Bobbit worm has cropped up in other aquariums, but sadly they have been discovered too late, as the answer to spates of unexplained fish disappearances.
"Our alien is safely in its own tank, under the watchful eye of our staff."