RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Alre

Largest measured brook lamprey: 13.4 cm

The largest brook lamprey measured in Environment Agency surveys of the River Alre was 13.4 cm, recorded at Arle 1: Arle Mill on 7 September 2017.

Across 2 measured brook lamprey, the median measured length was 12.7 cm.

RiverFish uses Environment Agency survey measurements rather than rod-and-line angling records. These figures show fish measured during EA surveys of the River Alre.

See brook lamprey records across England →

Most recent observation11 August 2025Arle 1: Arle Mill · 12 fish
Largest measured brook lamprey
13.4 cm
Median length
12.7 cm
Fish measured
2
Survey locations
2

Individual EA measurements

Largest measured brook lamprey

The largest individual measurements in this river and species dataset. Equal measurements are retained as separate surveyed fish.

LengthSurvey dateSurvey locationSurvey ID
13.4 cm7 Sept 2017Arle 1: Arle Mill151503
12 cm7 Sept 2017Arle 1: Arle Mill151503

Lengths are direct survey measurements. RiverFish does not estimate fish weights from length.

Explore the river

Where brook lamprey were found

Each point marks a survey location with at least one brook lamprey record.

Choose a point on the map to see what was recorded there.

Map points are approximate and don’t show fishing access. Check local permissions before visiting.

Place surveyedFirst recordedLast recordedVisits finding brook lamprey
Arle 1: Arle Mill13 Sept 201111 Aug 20258
Arle 4: d/s Eel House29 Sept 201529 Sept 20151

Choose a point or table row to see the location. More survey visits can mean more records, but not necessarily more fish.

2011–2025

Survey records by year

Each bar shows how many survey visits recorded brook lamprey that year.

Fish measured by surveyors

Measured length distribution

See how the 2 measured fish were spread across different length ranges.

Smallest
12 cm
Lower quarter
12.4 cm
Median
12.7 cm
Upper quarter
13.1 cm
Largest
13.4 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Alre

Compare other species with enough survey and measurement data for a detailed page.

Bullhead Brown / sea trout European eel Pike Grayling

Before you fish

Good to know

These are past survey records, so the fish present today may be different. Map points are approximate—check local access, permissions and fishing rules before visiting.

Learn how RiverFish uses the data →