RiverFish

Bullhead · Cottus gobio

Bullhead in the River Glaven

Largest measured bullhead: 12.2 cm

The largest bullhead measured in Environment Agency surveys of the River Glaven was 12.2 cm, recorded at Upstream Thornage Ford on 14 January 1988.

Across 7,636 measured bullhead, the median measured length was 5.8 cm.

Surveyors recorded weights for 24 bullhead. The median was 0.1 oz (0.002 kg) and the largest recorded weight was 0.7 oz (0.019 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 Glaven.

See bullhead records across England →

Most recent observation16 June 2026Upstream Glandford Mill · 21 fish
Largest measured bullhead
12.2 cm
Median length
5.8 cm
Fish measured
7,636
Survey locations
13

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
12.2 cm14 Jan 1988Upstream Thornage Ford16836
11.7 cm11 Jan 1988Hunworth16833
11.5 cm18 Jan 1988Letheringsett16837
11.5 cm11 Jan 1988Hunworth16833
11.3 cm11 Jan 1988Hunworth16833
11.2 cm13 Jan 1988Thornage Bridge16835
11.1 cm12 Jan 1988D/s Hunworth railway bridge16834
11 cm5 Feb 2003Hempstead , Split Hills Plantation99824
11 cm13 Jan 1988Thornage Bridge16835
11 cm11 Jan 1988Hunworth16833

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 Glandford Mill8 Jul 199916 Jun 20267
Letheringsett18 Jan 198821 May 202610
Upstream Thornage Ford14 Jan 198816 May 202513
D/s Hunworth railway bridge12 Jan 19887 May 202517
Upstream Wiveton Bridge19 May 200811 Jul 20235
Thornage Bridge13 Jan 19888 Jun 20239
Hempstead Mill bridge23 Jan 20035 Dec 20143
Hunworth Rail Bridge U/s12 May 20085 Jun 20148
Hunworth11 Jan 198829 Apr 20085
Hempstead Hall5 Feb 20033 Apr 20082
u/s B1149 bridge, Holt6 Feb 20036 Feb 20031
Hempstead, Green Farm trackway d/s5 Feb 20035 Feb 20031
Hempstead , Split Hills Plantation5 Feb 20035 Feb 20031

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

1988–2026

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 7,636 measured fish were spread across different length ranges.

Smallest
1.9 cm
Lower quarter
5 cm
Median
5.8 cm
Upper quarter
6.9 cm
Largest
12.2 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 24 bullhead. This is a subset of the measured fish and may not represent the whole population.

Lightest
0 oz (0.0005 kg)
Lower quarter
0 oz (0.001 kg)
Median
0.1 oz (0.002 kg)
Upper quarter
0.2 oz (0.0055 kg)
Heaviest
0.7 oz (0.019 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 Glaven

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

3-spined stickleback European eel Brook lamprey Pike Perch Roach

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 →