RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Alde (Main Reaches)

Largest measured brook lamprey: 12.8 cm

The largest brook lamprey measured in Environment Agency surveys of the River Alde (Main Reaches) was 12.8 cm, recorded at Upstream Langham Bridge on 14 July 2010.

Across 12 measured brook lamprey, the median measured length was 10.5 cm.

Surveyors recorded weights for 10 brook lamprey. The median was 0.1 oz (0.0027 kg) and the largest recorded weight was 0.1 oz (0.004 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 Alde (Main Reaches).

See brook lamprey records across England →

Most recent observation9 May 2024Upstream Langham Bridge · 1 fish
Largest measured brook lamprey
12.8 cm
Median length
10.5 cm
Fish measured
12
Survey locations
3

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
12.8 cm14 Jul 2010Upstream Langham Bridge122774
11.8 cm4 Jul 2016Upstream Langham Bridge148819
11 cm14 Jul 2010Upstream Langham Bridge122774
10.8 cm14 Jul 2010Upstream Langham Bridge122774
10.7 cm14 Jul 2010Upstream Langham Bridge122774
10.7 cm14 Jul 2010Upstream Langham Bridge122774
10.3 cm14 Jul 2010Upstream Langham Bridge122774
10 cm25 Mar 2003Upstream Langham Bridge79271
9.5 cm25 Mar 2003Upstream Langham Bridge79271
9.4 cm14 Jul 2010Upstream Langham Bridge122774

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
Upstream Langham Bridge25 Mar 20039 May 20244
Upstream Blaxhall Railway Bridge5 Nov 19875 Nov 19871
Upstream Farnham Bridge3 Nov 19873 Nov 19871

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

1987–2024

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 12 measured fish were spread across different length ranges.

Smallest
4.8 cm
Lower quarter
9.5 cm
Median
10.5 cm
Upper quarter
10.9 cm
Largest
12.8 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 10 brook lamprey. This is a subset of the measured fish and may not represent the whole population.

Lightest
0.1 oz (0.0018 kg)
Lower quarter
0.1 oz (0.0023 kg)
Median
0.1 oz (0.0027 kg)
Upper quarter
0.1 oz (0.0034 kg)
Heaviest
0.1 oz (0.004 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 Alde (Main Reaches)

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

European eel Dace Roach Stone loach 3-spined stickleback Flounder

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 →