Bullhead · Cottus gobio

Bullhead in the Cogwell Brook

Largest measured bullhead: 7.6 cm

The largest bullhead measured in Environment Agency surveys of the Cogwell Brook was 7.6 cm, recorded at W049n on 13 September 2013.

Across 21 measured bullhead, the median measured length was 3.6 cm.

RiverFish uses Environment Agency survey measurements rather than rod-and-line angling records. These figures show fish measured during EA surveys of the Cogwell Brook.

See bullhead records across England →

Most recent observation21 August 2025W049n

Largest measured bullhead: 7.6 cm
Median length: 3.6 cm
Fish measured: 21
Survey locations: 2

Individual EA measurements

Largest measured bullhead

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
7.6 cm	13 Sept 2013	W049n	138713
7.5 cm	13 Sept 2013	W049n	138713
6 cm	13 Sept 2013	W049n	138713
4.8 cm	13 Sept 2013	W049n	138713
4.5 cm	13 Sept 2013	W049n	138713
4.2 cm	13 Sept 2013	W049n	138713
4 cm	13 Sept 2013	W049n	138713
4 cm	13 Sept 2013	W049n	138713
4 cm	13 Sept 2013	W049n	138713
3.9 cm	13 Sept 2013	W049n	138713

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

Explore the river

Where bullhead were found

Each point marks a survey location with at least one bullhead 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 bullhead
W049n	14 Jul 1992	21 Aug 2025	8
W171L	11 Jul 2003	11 Jul 2003	1

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

1992–2025

Survey records by year

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

192

093

194

095

096

097

098

099

000

001

002

203

004

005

006

007

008

109

010

011

012

113

014

015

016

017

018

119

020

021

022

023

124

125

Fish measured by surveyors

Measured length distribution

See how the 21 measured fish were spread across different length ranges.

Smallest: 1.8 cm
Lower quarter: 3 cm
Median: 3.6 cm
Upper quarter: 4.2 cm
Largest: 7.6 cm

0–99 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Cogwell Brook

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

Brown / sea trout

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 →