RiverFish

Gudgeon · Gobio gobio

Gudgeon in the River Thames

Largest measured gudgeon: 16.7 cm

The largest gudgeon measured in Environment Agency surveys of the River Thames was 16.7 cm, recorded at Shifford Fish Pass on 2 November 2022.

Across 4,242 measured gudgeon, the median measured length was 9.5 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 Thames.

See gudgeon records across England →

Most recent observation16 October 2025Hannington Bridge · 14 fish
Largest measured gudgeon
16.7 cm
Median length
9.5 cm
Fish measured
4,242
Survey locations
61

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
16.7 cm2 Nov 2022Shifford Fish Pass162074
16.2 cm11 Oct 2013Castle Eaton139770
16.2 cm22 Oct 2009Castle Eaton120445
16 cm6 Oct 2006Buscot to Grafton101726
15.9 cm22 Oct 2009Cricklade120636
15 cm22 Oct 2009Castle Eaton120445
15 cm22 Oct 2009Castle Eaton120445
15 cm5 Jun 2003Culham - Clifton Hampden (Margin)76433
14.8 cm15 Oct 2008Water eaton115978
14.7 cm22 Oct 2009Cricklade120636

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
Hannington Bridge29 Aug 200316 Oct 202510
Castle Eaton23 May 200216 Oct 202515
Cricklade23 May 200214 Oct 202514
Godstow to Osney19 Jun 200126 Sept 202515
Eynsham- kings1 Oct 200326 Sept 202512
Northmoor- Pinkhill26 Sept 200325 Sept 202512
Rushey to Shifford7 Jun 200124 Sept 20259
Buscot to Grafton5 Jun 200123 Sept 202513
Whitchurch to Mapledurham (Margin)12 Jul 200122 Jul 202512
Abingdon Weirpool14 Jul 201015 Jul 20254
Sandford - Abingdon - (Margin)20 Sept 199310 Jul 202528
Iffley - Sandford (Margin)11 Jul 19999 Jul 202514
Roundhouse to St Johns(margins)26 Jun 200212 Sept 202415
Clifton Hampden - Days (Margin)23 Sept 199313 Jul 202425
Culham - Clifton Hampden (Margin)22 Sept 199322 Jul 202321
Abingdon - Culham (Margin)21 Sept 199321 Jul 202322
Shifford Fish Pass2 Nov 20222 Nov 20221
Water eaton2 Oct 200218 Oct 202213
Hambleden - Hurley (margin)24 Jul 200127 Jul 202211
Cleeve - Goring (Weirpool)14 Jul 200523 Jul 20222
Whitchurch (Weirpool)12 Jul 200126 Jul 20197
Port Meadow (Day/Night)22 Jun 201816 Jul 20196
Godstow Weirpool5 Oct 201515 Jul 20194
Canal confluence to Marina4 Oct 20184 Oct 20181
Culham Weirpool17 Jul 201515 Jul 20172
Sandford Weir stream7 Jul 200913 Jul 20175
Caversham-sonning - (Margin)17 Jul 200110 Jul 20167
Days weirpool25 Jul 20127 Jul 20162
Days - Benson (Margin)24 Sept 19937 Jul 201617
Clifton Weir Stream10 Jul 200918 Jul 20156
Rushey bypass channel18 Sept 201418 Sept 20141
Mapledurham Mill Channel16 Apr 201416 Apr 20141
Radcot - Rushey17 Oct 201317 Oct 20131
Buscot weir pool5 Oct 201016 Oct 20132
Radcot Fish Pass25 Sept 201325 Sept 20131
Hailstone farm18 Mar 200421 Aug 20132
Shiplake-marsh - (Margin)20 Jul 200413 Jul 20136
Shiplake - Marsh (Weirpool)13 Jul 201313 Jul 20131
Cerney Wick Brook31 Mar 200410 Apr 20132
Goring to Whitchurch (Margin)13 Jul 200928 Jul 20124
Rushey Weir Pool12 Oct 200425 Oct 20113
Hambleden - Hurley (Weirpool)25 Jul 201125 Jul 20111
Goring weir pool20 Jul 201120 Jul 20111
Cleeve-Goring - (Margin)3 Jul 200119 Jul 20113
Osney Weirpool-Fyke Netting20 Jun 201120 Jun 20111
Sonning - shiplake (Margin)17 Jul 200922 Jul 20102
Marsh - Hambleden (Margin)24 Jul 200824 Jul 20081
Eynsham Weir Stream17 Mar 20067 Sept 20073
Port Meadow1 Sept 20071 Sept 20071
St Patricks stream16 Nov 200616 Nov 20061
Clifton Hampden - Days (Middle)23 Sept 199310 Jul 20044
Culham - Clifton Hampden (Middle)22 Sept 19939 Jul 20047
Sandford - Abingdon - Middle20 Sept 19936 Jul 20048
Godstow weirstream1 Oct 20031 Oct 20031
400yds d/s hannington B-small trib on RB24 Sept 200224 Sept 20021
Abingdon - Culham (Middle)6 Jul 19947 Jul 20023
Roundhouse to St Johns(mid-river)26 Jun 200226 Jun 20021
Hambleden - Hurley (middle)24 Jul 200124 Jul 20011
Caversham-sonning - (Mid River)17 Jul 200117 Jul 20011
Whitchurch - Mapledurham (Middle)12 Jul 200112 Jul 20011
Days - Benson (Middle)8 Jul 19946 Jul 20002

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

1993–2025

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 4,242 measured fish were spread across different length ranges.

Smallest
2.5 cm
Lower quarter
8.2 cm
Median
9.5 cm
Upper quarter
10.9 cm
Largest
16.7 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Thames

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

Roach Bleak Pike Chub Perch Dace

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 →