RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Main Tamar

Largest measured brook lamprey: 19.7 cm

The largest brook lamprey measured in Environment Agency surveys of the River Main Tamar was 19.7 cm, recorded at u/s North Tamerton on 16 August 2018.

Across 24 measured brook lamprey, the median measured length was 12.8 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 Main Tamar.

See brook lamprey records across England →

Most recent observation6 August 2025Tamarstone · 3 fish
Largest measured brook lamprey
19.7 cm
Median length
12.8 cm
Fish measured
24
Survey locations
12

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.

LengthSurvey dateSurvey locationSurvey ID
19.7 cm16 Aug 2018u/s North Tamerton153728
15.5 cm15 Jul 2016Bridgerule148607
15 cm6 Aug 2025Tamarstone179031
15 cm6 Aug 2025Tamarstone179031
14.9 cm15 Jul 2016Bridgerule148607
14.8 cm19 May 2016u/s Tamar Lakes148060
14.5 cm28 Sept 2010u/s Tamar Lakes124790
14.3 cm19 May 2016u/s Tamar Lakes148060
14 cm19 May 2016u/s Tamar Lakes148060
13.9 cm6 Aug 2025Tamarstone179031

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 surveyedFirst recordedLast recordedVisits finding brook lamprey
Tamarstone5 Aug 20196 Aug 20253
Lowley Confluence23 Aug 202323 Aug 20231
Gordonhill Plantation23 Aug 202323 Aug 20231
Dexbeer6 Sept 20226 Sept 20221
u/s North Tamerton16 Aug 201816 Aug 20181
d/s Netherbridge19 Jul 201819 Jul 20181
Southcombe7 Sept 20167 Sept 20161
u/s Lamerhooe Ford19 Jul 201619 Jul 20161
Bridgerule15 Jul 201615 Jul 20161
u/s Tamar Lakes28 Sept 201019 May 20162
Gunnislake Weir Index River Fish Trap15 Dec 201315 Dec 20131
Gravel9 Aug 20109 Aug 20101

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

2010–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 24 measured fish were spread across different length ranges.

Smallest
8 cm
Lower quarter
10.5 cm
Median
12.8 cm
Upper quarter
14.6 cm
Largest
19.7 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Main Tamar

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

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

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 →