Head to head
Brook Lamprey vs River Lamprey
Brook Lamprey
VS River Lamprey
The brook lamprey and the river lamprey are close relatives in the same genus whose larvae look nearly identical, but their adult lives could hardly be more different.
| Brook Lamprey | River Lamprey | |
|---|---|---|
| Scientific name | Lampetra planeri | Lampetra fluviatilis |
| Relationship | A close relative in the same genus, and a non-parasitic cousin of the river lamprey | A close relative in the same genus, with a parasitic, sea-going life |
| Adult size | Usually only 9 to 15 cm long | Reaches around 25 to 40 cm in length |
| Larval life | Several years as a blind larva buried in soft silt, filtering algae and fine organic matter | Several years as a blind larva buried in soft river silt, filtering fine material |
| Adult feeding | Does not feed as an adult, as its gut shrinks after the larva changes into an adult | A parasite that fastens onto fish with its sucker mouth and rasps off flesh and blood |
| Migration | Never goes to sea, and lives in freshwater all its life | Moves down to estuaries and coastal waters to feed for a year or two, then returns to rivers in autumn |
| Spawning | Gathers in groups to spawn in clean gravel in spring, working stones aside to build a shallow nest, and then dies | Spawns in clean gravel in spring, working stones aside to make a shallow nest, before dying |
| Conservation status | Least Concern, and protected under European Union law, a sign of clean, gravelly streams | Least Concern, and protected under European Union law, but affected by dams, pollution, and the loss of spawning gravel |
Brook Lamprey vs River Lamprey: common questions
Which lamprey is a parasite?
The river lamprey, which fastens onto fish in estuaries and coastal waters, whereas the brook lamprey does not feed as an adult at all.
Which one goes to sea?
The river lamprey moves to estuaries and coastal waters for a year or two, while the brook lamprey never leaves freshwater.
What happens after they spawn?
Both die after spawning in clean gravel in spring.