Gudgeon · Gobio gobio

Gudgeon in the River Colne

Largest measured gudgeon: 18.9 cm

The largest gudgeon measured in Environment Agency surveys of the River Colne was 18.9 cm, recorded at Stanwell Moor on 29 August 2004.

Across 3,009 measured gudgeon, the median measured length was 10 cm.

Surveyors recorded weights for 342 gudgeon. The median was 0.9 oz (0.026 kg) and the largest recorded weight was 10.1 oz (0.287 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 Colne.

See gudgeon records across England →

Most recent observation21 July 2026Uxbridge · 1 fish

Largest measured gudgeon: 18.9 cm
Median length: 10 cm
Fish measured: 3,009
Survey locations: 29

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
18.9 cm	29 Aug 2004	Stanwell Moor	80765
17.3 cm	12 Mar 1986	Moor roundabout 2	116074
17.2 cm	25 Jun 2008	Springwell Lane	111527
17.1 cm	19 Feb 1986	Denham Court	116043
16.8 cm	17 Jun 1986	Harefield Road	116068
16.7 cm	12 Mar 1986	Moor roundabout 2	116074
16.7 cm	12 Mar 1986	Moor roundabout 2	116074
16.6 cm	12 Mar 1986	Moor roundabout 2	116074
16.6 cm	20 Feb 1986	Milupa Factory	116032
16.5 cm	25 Jun 2008	Springwell Lane	111527

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
Uxbridge	20 Aug 2002	21 Jul 2026	19
Watford M1 link road	21 Sept 2000	16 Jul 2026	19
Springwell Lane	11 Feb 1986	15 Jun 2026	24
Stanwell Moor	6 Mar 1986	28 May 2026	18
Wall Hall	6 Jul 2005	14 May 2026	19
Drop Lane	8 Jul 2003	23 May 2023	11
Watford Tesco Extra	26 Jul 2022	26 Jul 2022	1
Heathrow EP: Little Britain	31 Oct 2019	31 Oct 2019	1
Heathrow EP: Poyle Channel	28 Oct 2019	28 Oct 2019	1
The Withey Beds	20 May 2015	20 May 2015	1
u/s West Drayton Mill	24 Sept 2013	30 Sept 2014	2
Merchant Taylor Backwater	16 Sept 2013	16 Sept 2013	1
Longbridge Way, Uxbridge	29 May 2012	29 May 2012	1
Denham	20 Oct 1998	1 Aug 2009	4
Cowley, Old Mill Lane	19 May 2009	19 May 2009	1
Harefield Road	17 Jun 1986	17 Jun 1986	1
Old Mill Lane	12 Jun 1986	12 Jun 1986	1
Cricketfield Lane	16 May 1986	16 May 1986	1
Stanwell Road	8 May 1986	8 May 1986	1
Poyle Channel	7 May 1986	7 May 1986	1
Staines Moor	13 Mar 1986	13 Mar 1986	1
Moor roundabout 2	12 Mar 1986	12 Mar 1986	1
Staines	11 Mar 1986	11 Mar 1986	1
Moor Roundabout	4 Mar 1986	4 Mar 1986	1
Packetboat Lane	27 Feb 1986	27 Feb 1986	1
Uxbridge Moor	26 Feb 1986	26 Feb 1986	1
Milupa Factory	20 Feb 1986	20 Feb 1986	1
Denham Court	19 Feb 1986	19 Feb 1986	1
Maple Cross	12 Feb 1986	12 Feb 1986	1

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

1986–2026

Survey records by year

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

1686

087

088

089

090

091

092

093

094

095

096

097

198

099

100

201

302

403

504

505

706

607

508

809

510

311

712

513

314

715

416

317

518

719

020

021

422

623

524

525

526

Fish measured by surveyors

Measured length distribution

See how the 3,009 measured fish were spread across different length ranges.

Smallest: 1 cm
Lower quarter: 8.2 cm
Median: 10 cm
Upper quarter: 11.8 cm
Largest: 18.9 cm

0–99 mm

1470

100–199 mm

1539

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 342 gudgeon. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0 oz (0.0008 kg)
Lower quarter: 0.6 oz (0.016 kg)
Median: 0.9 oz (0.026 kg)
Upper quarter: 1.5 oz (0.043 kg)
Heaviest: 10.1 oz (0.287 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 Colne

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

Chub Perch Roach Pike Dace Bullhead

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 →