The ruffe (Gymnocephalus cernua), also called the pope or ruff, is one of the smallest percid fish in British freshwater and one of the most commonly caught accidental bycatch species on the river. A small, olive-mottled, spiky fish with two dorsal fins joined at their base, the ruffe is closely related to the perch but considerably smaller, rarely exceeding 6 inches. For the beginner who catches one while float fishing a canal or river and does not recognise it, the ruffe can be confusing – it looks superficially like a small perch but with spotted (not barred) markings and no bright colour in the fins.
Despite its small size, the ruffe is a notable invasive species in certain contexts. Introduced to Loch Lomond via ballast water in the 1980s, the ruffe has caused significant problems for vendace and other native species in that system, and is listed as an invasive non-native species in Scotland where it has been introduced beyond its native range.
[Image placeholder: A ruffe held between finger and thumb, showing its joined dorsal fin (spiny and soft sections), spotted olive-brown flanks, and downturned inferior mouth]
Identification
Ruffe are distinctive once recognised, though at first glance they may be mistaken for small perch:
Two dorsal fins joined at the base: Unlike perch (where there is a clear gap between the two dorsal fins), the spiny first dorsal and soft second dorsal of a ruffe are joined together with no separation.
No vertical barring: Ruffe have an all-over spotted and mottled pattern of olive-brown with darker spots. Perch have the distinctive 6-8 bold vertical bars. This is the quickest field difference.
Inferior mouth: Slightly downturned, bottom-feeding mouth position.
Coloration: Olive-green to greenish-brown on the back with dark spots. Flanks are lighter and mottled. Belly cream to pale yellow. Fins are without the vivid orange-red of a perch.
Size: Typically 3-6 inches (7-15cm). Rarely exceeds 6 inches in UK waters. A 5-inch ruffe is a good fish; anything over 6 inches (15cm) would be exceptional.
Distribution
Ruffe are native to most of England and Wales, particularly in slow, silty rivers, canals, and lowland lakes. They are absent from Scotland (other than as an introduced invasive species in Loch Lomond and a few other Scottish waters), Wales (native range limited), and Ireland.
Primary distribution: – Slow rivers and drains throughout England, particularly in the Midlands, East Anglia, and the North – Canals throughout the English network – Lowland lakes and shallow gravel pits – Abundant in the lower Thames, Trent, Great Ouse, and their tributaries
Habitat
Ruffe occupy the bottom zones of slower rivers, canals, and stillwaters:
- Silty, muddy bottoms in moderate to slow flow
- Canals (particularly areas with soft silt bottom and some current from lock activity)
- Slower river reaches and backwaters
- Shallow lowland lakes
Ruffe prefer slower, deeper water than gudgeon (which occupy fast, gravelly runs), although both species can be found in similar rivers occupying different microhabitats.
Seasonal Behaviour
Ruffe are active through summer and remain catchable well into late autumn and early winter. They are not as cold-tolerant as perch but continue feeding at lower temperatures than many other coarse fish.
Spring (March to June): Ruffe spawn in spring (April to June), in shallow water over gravel or submerged vegetation. They are catchable as soon as the river season opens in June.
Summer and autumn (June to November): Active feeders. Most ruffe are caught in summer and early autumn while targeting other species – they are very willing biters.
Winter (December to February): Activity reduces in cold water. Still catchable in mild conditions.
Spawning
Ruffe spawn in April to June when water temperatures exceed 10°C. Like perch, they produce ribbons or strands of eggs attached to stones or vegetation. They can spawn multiple times in a season. In suitable habitat they can produce very large numbers of juvenile fish quickly, which is part of what makes them successful invaders in new water bodies.
Size and British Record
The British record ruffe stands at 5oz 4dr (148g), caught by R.J. Jenkins in the River Colne in Staines in 1980. Check brfc.org for current figures.
Most UK ruffe are: – Typical catch: 1-2oz (10-12cm) – Good specimen: 3-4oz – Exceptional: 4oz+ (the record fish represents an extreme outlier)
Regulations
Standard coarse fish regulations apply. No minimum size, no bag limit nationally. Close season applies on rivers (15 March to 15 June). Rod licence required.
Important note for Scotland: Ruffe are classified as an invasive non-native species in Scotland (outside their native range). Handling and release in Scottish waters may be subject to restrictions. Do not transport live ruffe from one water to another.
Baits and Methods
Ruffe are caught almost exclusively as bycatch while targeting other bottom-feeding species. The key to catching them specifically is:
- Small hook: Size 18-22
- Small bait: Single maggot, pinkie, small worm section, bloodworm
- Bottom presentation: Float set to fish the bait on or just above the bottom (ruffe are bottom feeders with an inferior mouth)
- Slow or still presentation: Canal trotting or static leger with a fine tip
In match fishing on canals and rivers with ruffe populations, a small pinkie or bloodworm on a size 20-22 hook on pole tackle is the most precise method for specifically targeting them. In the right swim, a matchman targeting ruffe can accumulate a good weight from sheer numbers.
Ruffe as Invasive Species
In Loch Lomond, where ruffe were accidentally introduced in the 1980s (almost certainly via ballast water in a boat that had been transported from an English river or canal), they have caused significant ecological damage. Ruffe fed heavily on the eggs and larvae of the native vendace and Arctic charr, contributing to the near-extinction of the Loch Lomond vendace population. Ruffe removal programmes have been conducted in the loch, with limited success.
This case illustrates the importance of never moving fish between water bodies and always cleaning fishing equipment (boots, nets, waders) between venues.
Frequently Asked Questions
Is a ruffe the same as a pope?
Yes. The pope (or pope ruff) is an older English name for the same species, Gymnocephalus cernua. The name “pope” is now less commonly used; most UK anglers use “ruffe.”
How do I tell a ruffe from a small perch?
The two clearest differences: (1) ruffe have joined dorsal fins (spiny and soft sections connect with no gap), while perch have two clearly separate dorsal fins with a gap between; (2) ruffe are spotted/mottled without bold vertical bars, while perch have 6-8 strong vertical bars and vivid orange-red fins.
Can ruffe grow to a pound?
No. Ruffe are a very small species; the British record is just over 5oz. A fish over 4oz is exceptional. They will never be large enough to feature in carp-style specimen fishing; they are important for match anglers accumulating weight, and as ecological indicators of water quality.
Are ruffe harmful to other fish?
In their native English range, ruffe are a natural part of the ecosystem and not harmful. As an invasive species outside their native range (particularly in Scotland), they can be extremely damaging to native fish by competing for food and eating fish eggs and larvae. Never move ruffe between waters.
Where are ruffe found in the UK?
Ruffe are widespread in slow rivers, canals, and lowland lakes throughout England, particularly the Midlands, East Anglia, and the North. They are present in the Thames, Trent, Great Ouse, and the English canal network. They are invasive in Loch Lomond and a few other Scottish waters.