Brook lamprey · Lampetra planeri

Brook lamprey in the River Wenning

Largest measured brook lamprey: 20.5 cm

The largest brook lamprey measured in Environment Agency surveys of the River Wenning was 20.5 cm, recorded at Clapham Station on 23 August 2013.

Across 20 measured brook lamprey, the median measured length was 12 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 Wenning.

See brook lamprey records across England →

Most recent observation20 August 2025Greystonegill Bridge · 1 fish

Largest measured brook lamprey: 20.5 cm
Median length: 12 cm
Fish measured: 20
Survey locations: 4

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.

Length	Survey date	Survey location	Survey ID
20.5 cm	23 Aug 2013	Clapham Station	138526
17 cm	8 Aug 2014	Clapham Station	142289
14 cm	3 Aug 2010	Clapham Station	123212
14 cm	3 Aug 2010	Clapham Station	123212
14 cm	3 Aug 2010	Clapham Station	123212
13.5 cm	20 Aug 2025	Greystonegill Bridge	180043
13 cm	3 Aug 2010	Clapham Station	123212
13 cm	3 Aug 2010	Clapham Station	123212
12.5 cm	3 Aug 2010	Clapham Station	123212
12 cm	8 Aug 2014	Clapham Station	142289

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 surveyed	First recorded	Last recorded	Visits finding brook lamprey
Greystonegill Bridge	20 Aug 2025	20 Aug 2025	1
Clapham Station	3 Aug 2010	23 Aug 2018	4
Low Bentham	12 Jul 2013	12 Jul 2013	1
Hornby	12 Jul 2013	12 Jul 2013	1

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

2010–2025

Survey records by year

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

110

011

012

313

114

015

016

017

118

019

020

021

022

023

024

125

Fish measured by surveyors

Measured length distribution

See how the 20 measured fish were spread across different length ranges.

Smallest: 7 cm
Lower quarter: 10 cm
Median: 12 cm
Upper quarter: 13.6 cm
Largest: 20.5 cm

0–99 mm

100–199 mm

200–299 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Wenning

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

Brown / sea trout Atlantic salmon European eel

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 →