Brook lamprey · Lampetra planeri

Brook lamprey in the River US Lark

Largest measured brook lamprey: 17.1 cm

The largest brook lamprey measured in Environment Agency surveys of the River US Lark was 17.1 cm, recorded at US West Stow Country Park on 3 May 2023.

Across 10 measured brook lamprey, the median measured length was 14.2 cm.

Surveyors recorded weights for 9 brook lamprey. The median was 0.2 oz (0.005 kg) and the largest recorded weight was 0.3 oz (0.008 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 Lark.

See brook lamprey records across England →

Most recent observation3 May 2023US West Stow Country Park · 6 fish

Largest measured brook lamprey: 17.1 cm
Median length: 14.2 cm
Fish measured: 10
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
17.1 cm	3 May 2023	US West Stow Country Park	162306
16.6 cm	3 May 2023	US West Stow Country Park	162306
16.6 cm	3 May 2023	US West Stow Country Park	162306
16.5 cm	3 May 2023	US West Stow Country Park	162306
14.8 cm	9 Jul 2014	West Stow Country Park	141638
13.5 cm	12 Jul 2012	Tuddenham Heath	132312
13.4 cm	12 Jul 2012	Tuddenham Heath	132312
11.8 cm	21 Jul 2015	Tuddenham Heath	145599
11.2 cm	3 May 2023	US West Stow Country Park	162306
10.6 cm	3 May 2023	US West Stow Country Park	162306

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
US West Stow Country Park	3 May 2023	3 May 2023	1
Tuddenham Heath	12 Jul 2012	21 Jul 2015	2
West Stow Country Park	8 Jun 1992	9 Jul 2014	3
Temple Weir	23 Feb 2000	23 Feb 2000	1

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

1992–2023

Survey records by year

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

192

093

094

095

096

097

098

099

200

001

002

003

004

005

006

007

008

009

010

011

112

013

114

115

016

017

018

019

020

021

022

123

Fish measured by surveyors

Measured length distribution

See how the 10 measured fish were spread across different length ranges.

Smallest: 10.6 cm
Lower quarter: 12.2 cm
Median: 14.2 cm
Upper quarter: 16.6 cm
Largest: 17.1 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 9 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: 0.2 oz (0.005 kg)
Median: 0.2 oz (0.005 kg)
Upper quarter: 0.3 oz (0.0075 kg)
Heaviest: 0.3 oz (0.008 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 Lark

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

Stone loach Gudgeon Chub Roach Minnow 3-spined stickleback

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 →