Brook lamprey · Lampetra planeri

Brook lamprey in the River Bollin

Largest measured brook lamprey: 17 cm

The largest brook lamprey measured in Environment Agency surveys of the River Bollin was 17 cm, recorded at Bobo31 on 13 August 2025.

Across 6 measured brook lamprey, the median measured length was 15.5 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 Bollin.

See brook lamprey records across England →

Most recent observation13 August 2025Bobo31 · 1 fish

Largest measured brook lamprey: 17 cm
Median length: 15.5 cm
Fish measured: 6
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 cm	13 Aug 2025	Bobo31	180032
16 cm	21 Sept 2022	Bo07	162183
16 cm	7 Sept 2022	Bo08	161990
15 cm	7 Sept 2022	Bo08	161990
14 cm	15 Sept 2022	Bobo19	161996
13 cm	15 Sept 2022	Bobo19	161996

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
Bobo31	13 Aug 2025	13 Aug 2025	1
Bo07	21 Sept 2022	21 Sept 2022	1
Bobo19	15 Sept 2022	15 Sept 2022	1
Bo08	7 Sept 2022	7 Sept 2022	1

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

2022–2025

Survey records by year

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

322

023

024

125

Fish measured by surveyors

Measured length distribution

See how the 6 measured fish were spread across different length ranges.

Smallest: 13 cm
Lower quarter: 14.3 cm
Median: 15.5 cm
Upper quarter: 16 cm
Largest: 17 cm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Bollin

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

Stone loach 3-spined stickleback Bullhead Gudgeon Brown / sea trout 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 →