Ruffe · Gymnocephalus cernuus

Ruffe in the River Colne

Largest measured ruffe: 13.4 cm

The largest ruffe measured in Environment Agency surveys of the River Colne was 13.4 cm, recorded at Elms Lake on 19 February 2004.

Across 31 measured ruffe, the median measured length was 10 cm.

Surveyors recorded weights for 6 ruffe. The median was 0.6 oz (0.018 kg) and the largest recorded weight was 1 oz (0.0271 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 ruffe records across England →

Most recent observation1 August 2022Springwell Lane · 1 fish

Largest measured ruffe: 13.4 cm
Median length: 10 cm
Fish measured: 31
Survey locations: 4

Individual EA measurements

Largest measured ruffe

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
13.4 cm	19 Feb 2004	Elms Lake	79907
12.4 cm	19 Feb 2004	Elms Lake	79907
12 cm	12 Feb 1986	Maple Cross	115814
11.8 cm	12 Feb 1986	Maple Cross	115814
11.7 cm	19 Feb 2004	Elms Lake	79907
11.4 cm	19 Feb 2004	Elms Lake	79907
11.4 cm	19 Feb 2004	Elms Lake	79907
11.2 cm	19 Feb 2004	Elms Lake	79907
11.2 cm	19 Feb 2004	Elms Lake	79907
11 cm	19 Feb 2004	Elms Lake	79907

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

Explore the river

Where ruffe were found

Each point marks a survey location with at least one ruffe 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 ruffe
Springwell Lane	5 Jul 2017	1 Aug 2022	2
Denham	9 Aug 2007	9 Aug 2007	1
Elms Lake	19 Feb 2004	19 Feb 2004	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.

1986–2022

Survey records by year

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

186

087

088

089

090

091

092

093

094

095

096

097

098

099

000

001

002

003

104

005

006

107

008

009

010

011

012

013

014

015

016

117

018

019

020

021

122

Fish measured by surveyors

Measured length distribution

See how the 31 measured fish were spread across different length ranges.

Smallest: 4.3 cm
Lower quarter: 7 cm
Median: 10 cm
Upper quarter: 11.2 cm
Largest: 13.4 cm

0–99 mm

100–199 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 6 ruffe. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.4 oz (0.01 kg)
Lower quarter: 0.5 oz (0.015 kg)
Median: 0.6 oz (0.018 kg)
Upper quarter: 0.9 oz (0.0248 kg)
Heaviest: 1 oz (0.0271 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 Gudgeon

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 →