River Lamprey
Species Information
Tiit Hunt [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons
Statistics
Scientific name: Lampetra fluviatilis
Length:Â up to 50cmÂ
Weight:Â up to 150g
Average lifespan:Â 4-8 years
Conservation status
Priority Species under the UK Post-2010 Biodiversity Framework.
When to see
January to December
About
The river lamprey is one of the most primitive fish alive today. They are jawless with a round sucker-mouth which it uses to attach to other fish to feed on them. Lamprey also feed on carrion. Lamprey are cartilaginous fish and as a result their skeletons are formed from a strong and flexible cartilage instead of bone.
Adult lamprey live and feed in coastal habitats and return to freshwater to spawn. During migration, adult river lampreys move upstream at night and rest in cover during the day. When they find a suitable breeding place, the male fish will sucker onto the female fish and wrap itself round her to ensure that the eggs she lays are fertilised. Spawning takes place from April to May on pebble and gravel substrates. The female river lamprey can lay up to 25,000 eggs with several males attached to her.
After spawning the adult fish die. Young hatching lamprey spend several years buried in silt until they reach adulthood when they will migrate to sea.Â
How to identify
Lampreys are an eel-like fish with a toothed, sucker-mouth. The river lamprey is a bluish-grey on the back and sides with a white underneath. It can be distinguished from other lamprey as it has two separate dorsal fins and a small number of teeth around its sucker. There are three species of lamprey in Scotland: the river lamprey, the brook lamprey and the sea lamprey. Â River lamprey are larger than brook lamprey, reaching 30 to 50cm in length, but smaller than sea lamprey.
Did you know ?
Populations of purely freshwater river lamprey are rare in Europe, but one population does exist in Scotland. They are known as dwarf river lamprey as they reach a length of only 25cm and are found in Loch Lomond.
How you can help?Â
Did you know you can help wildlife in your local river ? You can do this in many ways from reporting pollution to SEPA, by not flushing wet wipes down the toilet and even at one of our many conservation volunteer days. Check out our Get Involved page for more information on how you can get involved with your local river.