This is the moment a rare sea lamprey was spotted swimming through a Worcester fish pass for the first time this year.

The eel-like creature, which is over a metre in length, was spotted at the Diglis Fish Pass on Tuesday night (April 11).

Sea lampreys, which are also known as vampire fish, are parasitic animals that attach themselves to the skin of a fish to feed on its blood.

They have long eel-like bodies and round, sucker-like mouths with circular rows of sharp teeth.

Lampreys live in seas and lakes but migrate up rivers to spawn, something many fish have struggled to do in the River Severn because of navigation weirs installed in Victorian times.

This is exactly why the Diglis Fish Pass was built.

“The fish pass built at Diglis is the biggest deep vertical slot fish pass in England and Wales and it has a unique underwater viewing window,” said a spokesperson for Unlocking the Severn, a restoration project building fish passages in six locations on the rivers Severn and Teme.

“River and sea lamprey are very rare and we’ve seen them comfortably cruising though,” the spokesperson added.

“Recently including one lamprey, also known as the ‘vampire fish’ hitching a ride on an Atlantic Salmon.”

£19.7 million conservation project

Unlocking the Severn is a joint venture between the Canal & River Trust, Severn Rivers Trust, Environment Agency and Natural England, with funding from the Heritage Lottery Fund and the EU LIFE Programme among others.

READ MORE: Moment biggest shoal of fish yet swim by Diglis fish pass

The £19.7 million project to build fish passes in Worcester was inspired by the struggle of a fish called the twaite shad, which was unable to reach its former freshwater habitats.

Worcester News: The sea lamprey is also known as the vampire fishThe sea lamprey is also known as the vampire fish

Construction of four fish passes at Diglis, Bevere, Lincomb and Holt, as well as the partial removal of Powick Weir and upgrades to Knightsford Weir, not only helped the shad but opened up the river to all sorts of species of fish.

You can book free tours of Diglis Island and the fish pass, which are provided by volunteers, and read more about the conservation work by visiting