Brook lamprey · Lampetra planeri

Brook lamprey in the River Tas

Largest measured brook lamprey: 19 cm

The largest brook lamprey measured in Environment Agency surveys of the River Tas was 19 cm, recorded at Upstream Hempnall Beck on 22 April 2005.

Across 70 measured brook lamprey, the median measured length was 12.1 cm.

Surveyors recorded weights for 28 brook lamprey. The median was 0.1 oz (0.002 kg) and the largest recorded weight was 0.5 oz (0.015 kg).

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

See brook lamprey records across England →

Most recent observation2 May 2024Downstream Stoke Mill · 15 fish

Largest measured brook lamprey: 19 cm
Median length: 12.1 cm
Fish measured: 70
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	22 Apr 2005	Upstream Hempnall Beck	84614
17.8 cm	28 Apr 2016	Upstream Shotesham Park	148297
17.5 cm	28 Apr 2016	Upstream Shotesham Park	148297
17.5 cm	15 Apr 2005	Markshall Bridge	84425
17 cm	19 Apr 2005	Downstream Stoke Mill	84428
17 cm	15 Apr 2005	Markshall Bridge	84425
16.8 cm	2 May 2024	Downstream Stoke Mill	166211
16.2 cm	27 May 2022	Downstream Stoke Mill	161829
15.5 cm	28 Apr 2016	Upstream Shotesham Park	148297
15.5 cm	15 Apr 2005	Markshall Bridge	84425

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
Downstream Stoke Mill	22 May 2000	2 May 2024	6
Upstream Shotesham Park	28 Apr 2016	30 Apr 2024	3
Markshall Bridge	15 Apr 2005	25 Apr 2024	3
Upstream Hempnall Beck	22 Apr 2005	22 Apr 2005	1

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

2000–2024

Survey records by year

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

100

001

002

003

004

305

006

007

008

009

110

011

012

013

014

015

216

017

018

019

020

021

322

023

324

Fish measured by surveyors

Measured length distribution

See how the 70 measured fish were spread across different length ranges.

Smallest: 6.1 cm
Lower quarter: 10.5 cm
Median: 12.1 cm
Upper quarter: 14 cm
Largest: 19 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 28 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 (0.002 kg)
Median: 0.1 oz (0.002 kg)
Upper quarter: 0.1 oz (0.0042 kg)
Heaviest: 0.5 oz (0.015 kg)

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

More fish in this river

Explore the River Tas

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

European eel Stone loach Roach Bullhead Dace Pike

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 →