Petromyzon & Lampetra species
Petromyzon & Lampetra species
The prehistoric parasite older than the dinosaurs, Lamprey are a fascinating, yet terrifying rare ancient fish that is protected by law.
Biggest threats? Artifical barriers in rivers, such as weirs (lamprey are not strong swimmers and struggle to get up them); habitat destruction and pollution.
Three types of lamprey are found in the Eden catchment
Brook Lamprey (up to 20cm long)
River Lamprey (up to 40 cm)
Sea Lamprey (up to 1.2m)
They live for around 8 years, and spend the first 5-6 years of their lives living in a sandy/silty area of the riverbed
Lamprey have been popular as food for thousands of years and are still considered a delicacy in parts of Europe. Rumour has it that King Henry I of England died from overdosing on lamprey!
Lamprey are prehistoric fish that have existed for millions of years—long before dinosaurs roamed the Earth. With their snake-like appearance and seven pairs of breathing holes instead of gills, they’re unlike any other fish found in UK rivers.
Three species live in the River Eden, Brook lamprey, River lamprey and Sea lamprey (the largest, growing up to 120 cm long)
Lamprey are vertebrates, but their skeleton is made of cartilage, not bones. They are jawless, which means that their mouths are permanently open, forming a circular suction disc, lined with concentric rows of hooked teeth—perfectly adapted for their parasitic lifestyle.
It’s rare to find all three species of lamprey in a single river, but the River Eden provides ideal conditions. Its extensive deposits of gravel and fine silt create perfect spawning and nursery habitats, supporting the full lifecycle of brook, river, and sea lamprey.
Both river and sea lamprey are parasitic. They attach themselves to other fish and feed on their flesh and internal organs. Their powerful tongues act like drills, scraping through skin to access blood and tissue. While this sounds alarming, lamprey attacks on humans are extremely rare.
Sometimes, lamprey hitch a ride by clinging to larger fish—especially during upstream migrations to breed.
All three species of lamprey are rare and are protected species.
Lamprey use the turbulence from their body movements to shift pebbles and build nests, known as redds, in the riverbed.
The brook lamprey has a unique lifecycle. It only develops eyes and a mouth when it reaches adulthood. At that point, it stops feeding entirely and uses its sucker-like mouth solely to move sand and gravel to construct its nest.
River and Sea lamprey migrate out to sea for part of their lives. They feed parasitically on other fish, attaching themselves with their strange, toothed, sucker-like mouths. Sometimes they cling onto a fish just to get a lift - especially when migrating upstream to breed.
Brook lamprey only develop eyes and a mouth when they are adults. At this point, it stops feeding and only uses its sucker-like mouth to pick up and move sand and gravel to make a nest in the riverbed.
