Brook lamprey · Lampetra planeri

Brook lamprey in the River Gannel

Largest measured brook lamprey: 13.8 cm

The largest brook lamprey measured in Environment Agency surveys of the River Gannel was 13.8 cm, recorded at Benny Mill on 18 May 2021.

Across 16 measured brook lamprey, the median measured length was 8.8 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 Gannel.

See brook lamprey records across England →

Most recent observation20 May 2021Trewerry Mill · 7 fish

Largest measured brook lamprey: 13.8 cm
Median length: 8.8 cm
Fish measured: 16
Survey locations: 3

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
13.8 cm	18 May 2021	Benny Mill	160509
12 cm	23 May 2011	Gwills	126532
10.5 cm	20 May 2021	Trewerry Mill	160511
10.5 cm	3 Oct 2018	Gwills	153775
10 cm	20 May 2021	Trewerry Mill	160511
9.8 cm	23 May 2011	Gwills	126532
9.5 cm	23 May 2011	Gwills	126532
9.2 cm	20 May 2021	Trewerry Mill	160511
8.5 cm	20 May 2021	Trewerry Mill	160511
8.5 cm	20 May 2021	Trewerry Mill	160511

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
Trewerry Mill	20 May 2021	20 May 2021	1
Benny Mill	18 May 2021	18 May 2021	1
Gwills	23 May 2011	3 Oct 2018	2

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

2011–2021

Survey records by year

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

111

012

013

014

015

016

017

118

019

020

221

Fish measured by surveyors

Measured length distribution

See how the 16 measured fish were spread across different length ranges.

Smallest: 6.8 cm
Lower quarter: 8.2 cm
Median: 8.9 cm
Upper quarter: 10.1 cm
Largest: 13.8 cm

0–99 mm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Gannel

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

Brown / sea trout European eel Bullhead

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 →