Brook lamprey · Lampetra planeri

Brook lamprey in the River Main Deer

Largest measured brook lamprey: 19 cm

The largest brook lamprey measured in Environment Agency surveys of the River Main Deer was 19 cm, recorded at Derriton Bridge on 31 May 2018.

Across 7 measured brook lamprey, the median measured length was 16 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 Main Deer.

See brook lamprey records across England →

Most recent observation27 May 2022Forda Mill · 1 fish

Largest measured brook lamprey: 19 cm
Median length: 16 cm
Fish measured: 7
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
19 cm	31 May 2018	Derriton Bridge	154532
17.9 cm	25 May 2016	Derriton Bridge	148140
16.5 cm	21 Jun 2010	Forda Mill	122472
16 cm	21 Jun 2010	Forda Mill	122472
15.2 cm	1 Jun 2018	Forda Mill	154533
14.6 cm	31 May 2018	Derriton Bridge	154532
13.2 cm	27 May 2022	Forda Mill	161951

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
Forda Mill	21 Jun 2010	27 May 2022	3
Derriton Bridge	25 May 2016	31 May 2018	2
Babington Bridge	24 Sept 1996	24 Sept 1996	1
Gulliver Bridge	23 Sept 1996	23 Sept 1996	1

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

1996–2022

Survey records by year

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

296

097

098

099

000

001

002

003

004

005

006

007

008

009

110

011

012

013

014

015

116

017

218

019

020

021

122

Fish measured by surveyors

Measured length distribution

See how the 7 measured fish were spread across different length ranges.

Smallest: 13.2 cm
Lower quarter: 14.9 cm
Median: 16 cm
Upper quarter: 17.2 cm
Largest: 19 cm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Main Deer

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

Brown / sea trout Bullhead Minnow Stone loach European eel Atlantic salmon

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 →