RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Western Rother

Largest measured brook lamprey: 17 cm

The largest brook lamprey measured in Environment Agency surveys of the River Western Rother was 17 cm, recorded at Coultershaw on 1 August 2008.

Across 166 measured brook lamprey, the median measured length was 12.2 cm.

Surveyors recorded weights for 72 brook lamprey. The median was 0.1 oz (0.004 kg) and the largest recorded weight was 0.4 oz (0.011 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 Western Rother.

See brook lamprey records across England →

Most recent observation18 June 2026Coultershaw · 6 fish
Largest measured brook lamprey
17 cm
Median length
12.2 cm
Fish measured
166
Survey locations
10

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
17 cm1 Aug 2008Coultershaw112414
16.4 cm5 Jul 2002Empshott Mill52040
16 cm26 Jul 2010Coultershaw123941
15.9 cm28 Jun 2005Durford Bridge86719
15.5 cm13 Jul 2004Durford Bridge80587
15.2 cm20 Jul 2004Adhurst80738
15.1 cm2 Jul 2004Empshott Mill80298
15 cm3 Aug 2010Fittleworth Bridge123945
15 cm24 Jun 2008Stanbridge111610
15 cm13 Jul 2006Durford Bridge101869

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
Coultershaw24 Jul 200218 Jun 20269
Terwick Mill15 Jul 200316 Jun 202612
Stanbridge24 Jun 200831 Jul 202514
Fittleworth Bridge3 Aug 201020 Jun 20246
Liss9 Aug 201218 Jul 20182
Durford Bridge17 Jul 20022 Sept 20146
Woolbeding22 Jul 200924 Jul 20132
Adhurst10 Jul 20032 Jul 20075
Cowdray Estate6 Jul 200519 Sept 20062
Empshott Mill4 Oct 200129 Jun 20066

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

2001–2026

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 166 measured fish were spread across different length ranges.

Smallest
1.3 cm
Lower quarter
10.6 cm
Median
12.2 cm
Upper quarter
13.5 cm
Largest
17 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 72 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 (0.005 kg)
Heaviest
0.4 oz (0.011 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 Western Rother

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

European eel Brown / sea trout Bullhead Stone loach Minnow 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 →