RiverFish

Bullhead · Cottus gobio

Bullhead in the Main River Coly

Largest measured bullhead: 9 cm

The largest bullhead measured in Environment Agency surveys of the Main River Coly was 9 cm, recorded at Upstream Cadhayne (Te) on 15 June 2021.

Across 449 measured bullhead, the median measured length was 5.4 cm.

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

See bullhead records across England →

Most recent observation11 July 2025Upstream Cadhayne (Te) · 5 fish
Largest measured bullhead
9 cm
Median length
5.4 cm
Fish measured
449
Survey locations
9

Individual EA measurements

Largest measured bullhead

The largest individual measurements in this river and species dataset. Equal measurements are retained as separate surveyed fish.

LengthSurvey dateSurvey locationSurvey ID
9 cm15 Jun 2021Upstream Cadhayne (Te)159923
8.5 cm15 Jun 2021Upstream Cadhayne (Te)159923
8.2 cm16 May 2022Upstream Cadhayne (Te)161081
8.2 cm15 Jun 2021Upstream Cadhayne (Te)159923
8.1 cm15 Jun 2021Upstream Cadhayne (Te)159923
8 cm16 May 2022Upstream Cadhayne (Te)161081
7.9 cm16 May 2022Upstream Colyford (Sp)160944
7.9 cm15 Jun 2021Upstream Cadhayne (Te)159923
7.8 cm15 Jun 2021Upstream Cadhayne (Te)159923
7.8 cm15 Jun 2021Upstream Cadhayne (Te)159923

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 surveyedFirst recordedLast recordedVisits finding bullhead
Upstream Cadhayne (Te)7 Jul 201611 Jul 20257
Downstream FT BR Cadhayne (5 min)30 Jun 202330 May 20242
Upstream Colyford (5 min)29 Jun 202324 May 20242
Upstream Chantry Bridge (5 min)30 Jun 202324 May 20242
Colemans Cross (5 min)28 Jun 202324 May 20242
Upstream Colyford (Sp)18 Jul 199729 Jun 20238
Woodbridge (Sp)18 Jul 199731 May 20239
Upstream Southleigh Str6 May 20206 May 20201
Heathayne (Te)*22 Jul 199727 Jun 201312

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

1997–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 449 measured fish were spread across different length ranges.

Smallest
2 cm
Lower quarter
4.9 cm
Median
5.4 cm
Upper quarter
6.1 cm
Largest
9 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Main River Coly

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

Brown / sea trout Stone loach European eel Minnow Atlantic salmon

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 →