Brook lamprey · Lampetra planeri

Brook lamprey in the River Cadnam

Largest measured brook lamprey: 14.8 cm

The largest brook lamprey measured in Environment Agency surveys of the River Cadnam was 14.8 cm, recorded at Wittensford Bridge on 30 September 2019.

Across 30 measured brook lamprey, the median measured length was 12 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 Cadnam.

See brook lamprey records across England →

Most recent observation17 September 2025Newbridge · 2 fish

Largest measured brook lamprey: 14.8 cm
Median length: 12 cm
Fish measured: 30
Survey locations: 2

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
14.8 cm	30 Sept 2019	Wittensford Bridge	155548
13.8 cm	30 Sept 2019	Newbridge	155545
13.4 cm	30 Sept 2019	Newbridge	155545
13 cm	16 Sept 2022	Wittensford Bridge	161534
13 cm	30 Sept 2019	Newbridge	155545
12.9 cm	3 Sept 2018	Newbridge	153660
12.7 cm	18 Sept 2008	Newbridge	116150
12.6 cm	30 Sept 2019	Newbridge	155545
12.5 cm	30 Sept 2019	Newbridge	155545
12.5 cm	30 Sept 2019	Newbridge	155545

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
Newbridge	18 Sept 2008	17 Sept 2025	11
Wittensford Bridge	25 Jul 2012	20 Sept 2024	6

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

2008–2025

Survey records by year

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

108

009

010

011

112

113

014

015

016

017

218

219

120

221

222

223

224

125

Fish measured by surveyors

Measured length distribution

See how the 30 measured fish were spread across different length ranges.

Smallest: 8.4 cm
Lower quarter: 10.6 cm
Median: 12 cm
Upper quarter: 12.6 cm
Largest: 14.8 cm

0–99 mm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Cadnam

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

Bullhead Minnow Stone loach Brown / sea trout Roach 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 →