Brook lamprey · Lampetra planeri

Brook lamprey in the River US Cam

Largest measured brook lamprey: 17 cm

The largest brook lamprey measured in Environment Agency surveys of the River US Cam was 17 cm, recorded at Pampisford Mill on 13 March 2025.

Across 19 measured brook lamprey, the median measured length was 14.5 cm.

Surveyors recorded weights for 17 brook lamprey. The median was 0.2 oz (0.005 kg) and the largest recorded weight was 1.8 oz (0.05 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 US Cam.

See brook lamprey records across England →

Most recent observation13 March 2025Pampisford Mill · 1 fish

Largest measured brook lamprey: 17 cm
Median length: 14.5 cm
Fish measured: 19
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
17 cm	13 Mar 2025	Pampisford Mill	175951
16.5 cm	9 Feb 2005	Pampisford Mill	84134
16 cm	16 Mar 2010	Hauxton Junction	121267
16 cm	16 Mar 2010	Hauxton Junction	121267
15.4 cm	5 Jul 2013	Sawston Paper Mill	136985
15 cm	14 Jun 2010	Pampisford Mill	122313
15 cm	16 Mar 2010	Hauxton Junction	121267
15 cm	9 Feb 2005	Sawston Paper Mill	84136
14.6 cm	4 Jul 2013	Pampisford Mill	136998
14.5 cm	14 Jun 2010	Pampisford Mill	122313

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
Pampisford Mill	29 Sept 1993	13 Mar 2025	6
Sawston Paper Mill	9 Feb 2005	5 Jul 2013	2
P.B.I (Trumpington Meadows)	22 Feb 2005	11 Nov 2010	3
DS Hauxton Mill Bridge	16 Mar 2010	11 Nov 2010	2
Hauxton Junction	16 Mar 2010	16 Mar 2010	1

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.

193

094

095

196

097

098

099

000

001

002

003

004

305

006

007

008

009

610

011

012

213

014

015

016

017

018

019

020

021

022

023

024

125

Fish measured by surveyors

Measured length distribution

See how the 19 measured fish were spread across different length ranges.

Smallest: 10 cm
Lower quarter: 13.6 cm
Median: 14.5 cm
Upper quarter: 15.2 cm
Largest: 17 cm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 17 brook lamprey. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.1 oz (0.002 kg)
Lower quarter: 0.1 oz (0.004 kg)
Median: 0.2 oz (0.005 kg)
Upper quarter: 0.2 oz (0.006 kg)
Heaviest: 1.8 oz (0.05 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 US Cam

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

Roach Chub Perch Gudgeon Dace Brown / sea trout

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 →