Brook Lamprey - Lampetra planeri

Head-body length: up to 25 cm at spawning. The brook lamprey is a primitive, jawless fish resembling an eel, and is the smallest of the lampreys found in the UK. The brook lamprey (Lampetra planeri) is the smallest of the British lampreys, and has two dorsal (back) fins which are in close contact. It is grey-blue to green in colour and during the spawning period the areas around the mouth and the anal opening become rusty red. Lampreys are some of the most primitive vertebrates alive today, they are known as Cyclostomes, which means 'round mouths' and refers to the fact that they are jawless, having instead a round sucker-like mouth. A further primitive characteristic is that the skeleton consists of cartilage and not bone. Lampreys are similar in shape to eels, and have a series of uncovered round gill openings (known as gill pores) on the sides of the head and a single nostril on the upper surface of the head

It is a non-migratory freshwater species, occurring in streams and occasionally in lakes in north-west Europe.

All year round.

Like other lamprey species, the brook lamprey requires clean gravel beds for spawning and soft marginal silt or sand for the larvae. It spawns mostly in parts of the river where the current is not too strong.

The Brook Lamprey has declined in some areas of the UK but is relatively widespread and common in parts of England. In Scotland it is generally absent north of the Great Glen. Red Data Book species.

 Rare in Leicestershire and Rutland where it is found only in the Gwash and Chater and smaller Charnwood rivers (including the Black Brook and River Lin)