RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Main Thrushel

Largest measured brook lamprey: 16.2 cm

The largest brook lamprey measured in Environment Agency surveys of the River Main Thrushel was 16.2 cm, recorded at Thrushelton on 6 August 2024.

Across 135 measured brook lamprey, the median measured length was 12.3 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 Main Thrushel.

See brook lamprey records across England →

Most recent observation4 August 2025Thrushelton · 5 fish
Largest measured brook lamprey
16.2 cm
Median length
12.3 cm
Fish measured
135
Survey locations
7

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
16.2 cm6 Aug 2024Thrushelton167731
15.5 cm22 Jul 2015Wrixhill Bridge145597
15.1 cm6 Aug 2024Thrushelton167731
15.1 cm21 Aug 2018Beaver153827
15 cm3 Sept 2021Beaver160591
14.5 cm3 Sept 2021Beaver160591
14.5 cm2 Sept 2021Wrixhill Bridge160590
14.5 cm9 Sept 2010Downstream Thrushelton123809
14.4 cm3 Sept 2021Beaver160591
14.4 cm30 Aug 2019Beaver155576

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
Thrushelton6 Aug 20244 Aug 20252
Tinhay Bridge17 Aug 20107 Jul 20259
Townleigh10 Aug 20096 Aug 202411
Beaver28 Aug 201326 Jul 20226
Oatnell1 Sept 20158 Sept 20212
Wrixhill Bridge22 Jul 20152 Sept 20212
Downstream Thrushelton9 Sept 20106 Jul 20112

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

2009–2025

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 135 measured fish were spread across different length ranges.

Smallest
6.5 cm
Lower quarter
11.5 cm
Median
12.3 cm
Upper quarter
13.2 cm
Largest
16.2 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Main Thrushel

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

Brown / sea trout Atlantic salmon Bullhead Stone loach European eel Minnow

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 →