Bullhead · Cottus gobio

Bullhead in the River Ash (Thames)

Largest measured bullhead: 6.7 cm

The largest bullhead measured in Environment Agency surveys of the River Ash (Thames) was 6.7 cm, recorded at Gaston Bridge on 13 October 2005.

Across 6 measured bullhead, the median measured length was 5.2 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 Ash (Thames).

See bullhead records across England →

Most recent observation5 September 2023Gaston Bridge

Largest measured bullhead: 6.7 cm
Median length: 5.2 cm
Fish measured: 6
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
6.7 cm	13 Oct 2005	Gaston Bridge	86943
6.3 cm	13 Oct 2005	Gaston Bridge	86943
5.5 cm	20 Aug 2010	Gaston Bridge	123561
5 cm	13 Oct 2005	Gaston Bridge	86943
4.3 cm	13 Oct 2005	Gaston Bridge	86943
4.2 cm	13 Oct 2005	Gaston Bridge	86943

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
Gaston Bridge	13 Oct 2005	5 Sept 2023	5
Ford Bridge Roundabout	20 Aug 2010	20 Aug 2010	1

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

2005–2023

Survey records by year

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

105

006

007

008

009

210

111

012

013

014

015

016

117

018

019

020

021

022

123

Fish measured by surveyors

Measured length distribution

See how the 6 measured fish were spread across different length ranges.

Smallest: 4.2 cm
Lower quarter: 4.5 cm
Median: 5.3 cm
Upper quarter: 6.1 cm
Largest: 6.7 cm

0–99 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Ash (Thames)

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

European eel Chub Dace Gudgeon Roach 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 →