Brook lamprey · Lampetra planeri

Brook lamprey in the River Uck

Largest measured brook lamprey: 17 cm

The largest brook lamprey measured in Environment Agency surveys of the River Uck was 17 cm, recorded at Buxted Bridge on 13 September 2023.

Across 144 measured brook lamprey, the median measured length was 11.8 cm.

Surveyors recorded weights for 9 brook lamprey. The median was 0.1 oz (0.004 kg) and the largest recorded weight was 0.2 oz (0.006 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 Uck.

See brook lamprey records across England →

Most recent observation14 August 2025Uckfield · 13 fish

Largest measured brook lamprey: 17 cm
Median length: 11.8 cm
Fish measured: 144
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	13 Sept 2023	Buxted Bridge	163709
14.8 cm	18 Aug 2021	Uckfield	160159
14.5 cm	14 Aug 2025	Uckfield	177952
14.4 cm	20 Aug 2003	Great Streele	77116
14.3 cm	5 Sept 2007	Owlsbury Farm	107232
14.2 cm	13 Sept 2023	Buxted Bridge	163709
14.2 cm	5 Sept 2007	Owlsbury Farm	107232
14.1 cm	5 Sept 2007	Owlsbury Farm	107232
14 cm	1 Aug 2024	Uckfield	166436
14 cm	10 Oct 2019	Upstream Isfield Gate	155714

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
Uckfield	11 Sept 2018	14 Aug 2025	6
Buxted Bridge	3 Nov 2009	13 Aug 2025	9
Isfield Weir	16 May 2014	7 Aug 2025	2
Upstream Isfield Gate	10 Oct 2019	10 Oct 2019	1
Tickerage Castle	20 Aug 2015	20 Aug 2015	1
Great Streele	20 Aug 2003	5 Sept 2013	3
Hastingsford Bridge	30 Apr 2013	30 Apr 2013	1
Owlsbury Farm	5 Sept 2007	5 Sept 2007	1

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

2003–2025

Survey records by year

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

103

004

005

006

107

008

209

010

011

112

313

114

215

016

117

218

219

020

121

022

223

224

325

Fish measured by surveyors

Measured length distribution

See how the 144 measured fish were spread across different length ranges.

Smallest: 7 cm
Lower quarter: 11 cm
Median: 11.8 cm
Upper quarter: 12.6 cm
Largest: 17 cm

0–99 mm

100–199 mm

129

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 9 brook lamprey. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.1 oz (0.004 kg)
Lower quarter: 0.1 oz (0.004 kg)
Median: 0.1 oz (0.004 kg)
Upper quarter: 0.2 oz (0.005 kg)
Heaviest: 0.2 oz (0.006 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 Uck

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

Stone loach Minnow Roach Bullhead Gudgeon 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 →