Brook lamprey · Lampetra planeri

Brook lamprey in the Main River Tone

Largest measured brook lamprey: 17 cm

The largest brook lamprey measured in Environment Agency surveys of the Main River Tone was 17 cm, recorded at Ash Farm (Salmon Project) on 4 May 2011.

Across 122 measured brook lamprey, the median measured length was 12.5 cm.

Surveyors recorded weights for 59 brook lamprey. The median was 0.1 oz (0.004 kg) and the largest recorded weight was 0.4 oz (0.01 kg).

RiverFish uses Environment Agency survey measurements rather than rod-and-line angling records. These figures show fish measured during EA surveys of the Main River Tone.

See brook lamprey records across England →

Most recent observation18 October 2022Roughmoor (Te)

Largest measured brook lamprey: 17 cm
Median length: 12.5 cm
Fish measured: 122
Survey locations: 8

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	4 May 2011	Ash Farm (Salmon Project)	126155
17 cm	4 May 2011	Ash Farm (Salmon Project)	126155
17 cm	16 Apr 2003	Hornshay Farm at Nynehead (Se-03)	75895
16.5 cm	8 May 2013	Bulland Lodge	135963
16.5 cm	1 Jul 2010	Bulland Lodge	122566
16.5 cm	16 Apr 2003	Hornshay Farm at Nynehead (Se-03)	75895
16 cm	8 May 2013	Ash Farm (Salmon Project)	135964
16 cm	8 May 2013	Ash Farm (Salmon Project)	135964
16 cm	16 Apr 2003	Hornshay Farm at Nynehead (Se-03)	75895
15.9 cm	1 Jul 2010	Bulland Lodge	122566

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
Roughmoor (Te)	3 Aug 2004	18 Oct 2022	3
Bulland Lodge	21 May 2009	8 May 2013	4
Ash Farm (Salmon Project)	28 May 2009	8 May 2013	3
Harpford Bridge	8 May 2008	8 May 2008	1
Parsonage Farm (Te)	22 Sept 2003	6 Oct 2004	2
Hornshay Farm at Nynehead (Se-03)	16 Apr 2003	16 Apr 2003	1
Greenham (Se-03)	16 Apr 2003	16 Apr 2003	1
Marshes Farm	7 Sept 2001	7 Sept 2001	1

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

2001–2022

Survey records by year

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

101

002

303

204

005

006

007

108

209

210

211

012

213

014

015

016

017

018

019

020

021

122

Fish measured by surveyors

Measured length distribution

See how the 122 measured fish were spread across different length ranges.

Smallest: 4 cm
Lower quarter: 10.6 cm
Median: 12.5 cm
Upper quarter: 14 cm
Largest: 17 cm

0–99 mm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 59 brook lamprey. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0 oz (0.001 kg)
Lower quarter: 0.1 oz (0.003 kg)
Median: 0.1 oz (0.004 kg)
Upper quarter: 0.2 oz (0.0055 kg)
Heaviest: 0.4 oz (0.01 kg)

These are direct individual weights recorded by Environment Agency surveyors. Combined bulk weights are not included.

More fish in this river

Explore the Main River Tone

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

Brown / sea trout Bullhead European eel Stone loach Minnow 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 →