RiverFish

Gudgeon · Gobio gobio

Gudgeon in the River Marlow

Largest measured gudgeon: 14.5 cm

The largest gudgeon measured in Environment Agency surveys of the River Marlow was 14.5 cm, recorded at Marlow Upstream Fry on 22 August 2024.

Across 859 measured gudgeon, the median measured length was 3.8 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 Marlow.

See gudgeon records across England →

Most recent observation4 September 2025Marlow Downstream Fry · 14 fish
Largest measured gudgeon
14.5 cm
Median length
3.8 cm
Fish measured
859
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
14.5 cm22 Aug 2024Marlow Upstream Fry166469
12 cm1 Sept 2023Marlow Upstream Fry164324
10.9 cm22 Aug 2024Marlow Upstream Fry166469
10.9 cm1 Sept 2023Marlow Upstream Fry164324
10.8 cm1 Sept 2023Marlow Downstream Fry164323
10.8 cm17 Aug 2010Marlow Upstream Fry124337
10.7 cm1 Sept 2023Marlow Downstream Fry164323
10.6 cm17 Aug 2010Marlow Upstream Fry124337
10.5 cm1 Sept 2023Marlow Upstream Fry164324
10.5 cm1 Sept 2023Marlow Downstream Fry164323

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
Marlow Downstream Fry26 Aug 20034 Sept 202515
Marlow Upstream Fry26 Aug 200322 Aug 202416

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

2003–2025

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 859 measured fish were spread across different length ranges.

Smallest
1.1 cm
Lower quarter
3.2 cm
Median
3.8 cm
Upper quarter
4.6 cm
Largest
14.5 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Marlow

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

Minnow Chub Roach Bleak Dace Perch

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 →