Gudgeon · Gobio gobio

Gudgeon in the River Box (Main Reaches)

Largest measured gudgeon: 17.5 cm

The largest gudgeon measured in Environment Agency surveys of the River Box (Main Reaches) was 17.5 cm, recorded at Polstead Mill on 9 May 1997.

Across 3,157 measured gudgeon, the median measured length was 10 cm.

Surveyors recorded weights for 26 gudgeon. The median was 0.4 oz (0.0105 kg) and the largest recorded weight was 0.7 oz (0.021 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 Box (Main Reaches).

See gudgeon records across England →

Most recent observation22 May 2026Stour Confluence · 89 fish

Largest measured gudgeon: 17.5 cm
Median length: 10 cm
Fish measured: 3,157
Survey locations: 6

Individual EA measurements

Largest measured gudgeon

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
17.5 cm	9 May 1997	Polstead Mill	13802
17.2 cm	13 May 1997	Polstead Ford	13803
17.2 cm	9 May 1997	Polstead Mill	13802
17.1 cm	9 May 1997	Polstead Mill	13802
17.1 cm	9 May 1997	Polstead Mill	13802
17.1 cm	16 Apr 1991	Polstead Mill	13788
17.1 cm	27 Mar 1985	Polstead Mill	13776
17 cm	7 Jun 2016	Scotland Street	148219
17 cm	29 Apr 1994	Polstead Mill	13795
16.9 cm	9 May 1997	Polstead Mill	13802

Lengths are direct survey measurements. RiverFish does not estimate fish weights from length.

Explore the river

Where gudgeon were found

Each point marks a survey location with at least one gudgeon 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 gudgeon
Stour Confluence	16 Sept 1981	22 May 2026	18
Scotland Street	26 Mar 1985	21 May 2026	16
Polstead Mill	27 Mar 1985	11 Jun 2024	8
Peyton Hall Farm	6 Jun 2024	6 Jun 2024	1
Thorington Mill	25 Mar 1985	8 May 2024	11
Polstead Ford	13 May 1997	7 May 2024	3

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

1981–2026

Survey records by year

Each bar shows how many survey visits recorded gudgeon that year.

181

082

083

084

485

086

087

488

089

090

491

092

093

494

095

096

597

098

099

400

001

002

003

004

005

306

007

008

009

210

011

312

013

214

315

216

017

518

019

020

121

222

023

624

025

226

Fish measured by surveyors

Measured length distribution

See how the 3,157 measured fish were spread across different length ranges.

Smallest: 3.1 cm
Lower quarter: 8.8 cm
Median: 10 cm
Upper quarter: 11.3 cm
Largest: 17.5 cm

0–99 mm

1524

100–199 mm

1633

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 26 gudgeon. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.2 oz (0.007 kg)
Lower quarter: 0.3 oz (0.0082 kg)
Median: 0.4 oz (0.0105 kg)
Upper quarter: 0.5 oz (0.0148 kg)
Heaviest: 0.7 oz (0.021 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 Box (Main Reaches)

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

European eel Brown / sea trout Stone loach Dace Roach 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 →