RiverFish

Gudgeon · Gobio gobio

Gudgeon in the River Old Windsor

Largest measured gudgeon: 12 cm

The largest gudgeon measured in Environment Agency surveys of the River Old Windsor was 12 cm, recorded at Old Windsor Downstream Fry on 21 August 2018.

Across 2,502 measured gudgeon, the median measured length was 3.9 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 Old Windsor.

See gudgeon records across England →

Most recent observation3 September 2025Old Windsor Upstream Fry · 780 fish
Largest measured gudgeon
12 cm
Median length
3.9 cm
Fish measured
2,502
Survey locations
2

Individual EA measurements

Largest measured gudgeon

The largest individual measurements in this river and species dataset. Equal measurements are retained as separate surveyed fish.

LengthSurvey dateSurvey locationSurvey ID
12 cm21 Aug 2018Old Windsor Downstream Fry153458
11.3 cm20 Sept 2006Old Windsor Upstream Fry111943
11 cm21 Aug 2018Old Windsor Downstream Fry153458
11 cm20 Sept 2006Old Windsor Downstream Fry111934
10.9 cm3 Sept 2025Old Windsor Downstream Fry178526
10.9 cm21 Aug 2018Old Windsor Downstream Fry153458
10.6 cm21 Aug 2018Old Windsor Downstream Fry153458
10.6 cm21 Aug 2012Old Windsor Downstream Fry135279
10.6 cm20 Sept 2006Old Windsor Upstream Fry111943
10.3 cm21 Aug 2018Old Windsor Downstream Fry153458

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 surveyedFirst recordedLast recordedVisits finding gudgeon
Old Windsor Upstream Fry9 Sept 20043 Sept 202516
Old Windsor Downstream Fry9 Sept 20043 Sept 202516

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

2004–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 2,502 measured fish were spread across different length ranges.

Smallest
1.1 cm
Lower quarter
3.3 cm
Median
3.9 cm
Upper quarter
4.6 cm
Largest
12 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Old Windsor

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

Dace Chub Roach Minnow Bleak 3-spined stickleback

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 →