Brook lamprey · Lampetra planeri

Brook lamprey in the River Lymn FMU

Largest measured brook lamprey: 19.5 cm

The largest brook lamprey measured in Environment Agency surveys of the River Lymn FMU was 19.5 cm, recorded at Stockwith Mill on 8 May 2007.

Across 25 measured brook lamprey, the median measured length was 15.6 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 Lymn FMU.

See brook lamprey records across England →

Most recent observation7 November 2025Mill Bridge · 1 fish

Largest measured brook lamprey: 19.5 cm
Median length: 15.6 cm
Fish measured: 25
Survey locations: 5

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
19.5 cm	8 May 2007	Stockwith Mill	105283
18.2 cm	8 May 2007	Stockwith Mill	105283
18.2 cm	8 May 2007	Stockwith Mill	105283
18.2 cm	8 May 2007	Stockwith Mill	105283
18 cm	8 May 2007	Stockwith Mill	105283
18 cm	30 Apr 2003	Partney Bridge	78667
16.5 cm	8 May 2007	Stockwith Mill	105283
16.5 cm	28 Apr 2003	Raithby Bridge	78456
16.4 cm	8 May 2007	Stockwith Mill	105283
16 cm	8 May 2007	Stockwith Mill	105283

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
Mill Bridge	29 Apr 2002	7 Nov 2025	2
Raithby Bridge	3 Mar 1993	11 Jul 2016	5
Stockwith Mill	2 Mar 1993	6 Jul 2016	4
Snipe Dales	26 Mar 2014	26 Mar 2014	1
Partney Bridge	3 Mar 1993	13 Jun 2012	4

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

1993–2025

Survey records by year

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

393

094

095

296

097

098

099

000

001

102

203

004

005

006

107

008

009

010

011

212

013

114

115

216

017

018

019

020

021

022

023

024

125

Fish measured by surveyors

Measured length distribution

See how the 25 measured fish were spread across different length ranges.

Smallest: 12.1 cm
Lower quarter: 14.4 cm
Median: 15.6 cm
Upper quarter: 16.5 cm
Largest: 19.5 cm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Lymn FMU

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

Bullhead Brown / sea trout European eel 3-spined stickleback Roach Perch

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 →