Brook lamprey · Lampetra planeri

Brook lamprey in the River Box (Main Reaches)

Largest measured brook lamprey: 21.2 cm

The largest brook lamprey measured in Environment Agency surveys of the River Box (Main Reaches) was 21.2 cm, recorded at Thorington Mill on 25 May 2012.

Across 602 measured brook lamprey, the median measured length was 16.1 cm.

Surveyors recorded weights for 602 brook lamprey. The median was 0.3 oz (0.0071 kg) and the largest recorded weight was 0.6 oz (0.016 kg).

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

See brook lamprey records across England →

Most recent observation12 July 2021Stour Confluence · 13 fish

Largest measured brook lamprey: 21.2 cm
Median length: 16.1 cm
Fish measured: 602
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.

Length	Survey date	Survey location	Survey ID
21.2 cm	25 May 2012	Thorington Mill	132341
21 cm	15 Apr 2015	Thorington Mill	144750
20.3 cm	22 Apr 2015	Stour Confluence	144638
20.3 cm	15 Apr 2015	Thorington Mill	144750
20.3 cm	25 May 2012	Thorington Mill	132341
20.2 cm	22 Apr 2015	Stour Confluence	144638
20.2 cm	15 Apr 2015	Thorington Mill	144750
20 cm	22 Apr 2015	Stour Confluence	144638
20 cm	15 Apr 2015	Thorington Mill	144750
20 cm	25 May 2012	Thorington Mill	132341

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
Stour Confluence	11 Apr 1988	12 Jul 2021	9
Thorington Mill	25 Mar 1985	31 May 2018	5

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

1985–2021

Survey records by year

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

185

086

087

188

089

090

091

092

093

294

095

096

097

098

099

100

001

002

003

004

005

006

007

008

009

010

011

212

013

114

215

116

017

218

019

020

121

Fish measured by surveyors

Measured length distribution

See how the 602 measured fish were spread across different length ranges.

Smallest: 6.2 cm
Lower quarter: 14.9 cm
Median: 16.2 cm
Upper quarter: 17.2 cm
Largest: 21.2 cm

0–99 mm

100–199 mm

583

200–299 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 602 brook lamprey. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0 oz (0.0005 kg)
Lower quarter: 0.2 oz (0.0056 kg)
Median: 0.3 oz (0.0071 kg)
Upper quarter: 0.3 oz (0.0089 kg)
Heaviest: 0.6 oz (0.016 kg)

These are direct individual weights recorded by Environment Agency surveyors. Combined bulk weights are not included.

More fish in this river

Explore the River Box (Main Reaches)

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

European eel Brown / sea trout Stone loach Dace Roach Chub

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 →