This horrific-looking prehistoric water monster has returned to England's rivers. Yay?
The lamprey is an eel-like fish that dates back hundreds of millions of years, well before the dinosaurs; many call it a "living fossil." The largest British species, the sea lamprey, can grow up to a metre in length and has circles of sharp teeth that it uses to latch onto other fish and feed on their blood. Fancy a swim?
While the lamprey still exists, it's rare in Britain, topping the UK Environment Agency's list of the rarest fish in England earlier this year. The agency has now announced, however, that the endangered fish has returned to its old river habitats, having been spotted for the first time since the 1800s.
While they look like they belong in a swamp, lampreys need clean water, and pollution caused by the Industrial Revolution led to a dramatic decline in their numbers in England. Mills and weirs built at the same time also held them back—like salmon, lamprey head upstream to spawn, and these structures act as obstacles.
The Environment Agency has been helping the creatures out by removing some blockages and also trialling technologies such as "lamprey tiles": ladders over weirs that "enable lamprey to squirm upwards using their sucker-like mouths to anchor themselves."
It's still difficult to see lamprey in England as despite the comeback they remain rare. There are three species in the rivers, and one of which stays in freshwater and two of which live mainly in the sea but come upstream to spawn, which is when you're most likely to see them.Whether they're a welcome sight or not, they're a good sign as they signal the waters are less polluted. And apparently they make a decent pie.