Gudgeon
By Alex Clayton · Updated 23 October 2026
The gudgeon fish (Gobio gobio) is a small, bottom-living fish of lowland rivers, usually 7 to 15 cm long, with two short barbels at the corners of its mouth. If you have just swung in a little whiskered fish from a gravelly river shallow, it is probably one.
Gudgeon in the UK earn their place on two counts. They shoal up and are easy to catch, which makes them a classic first fish for beginners and children, and on many rivers they help build a weight in matches.
This guide covers identification, how gudgeon differ from stone loach and minnow, size, habitat, catching them and the rules. For other species, see our coarse fish species guides.
Gudgeon Identification: The Key Features
Gudgeon identification starts at the mouth. Look underneath the head and count the barbels: a gudgeon has exactly two, one hanging from each corner of the mouth.
The rest of the fish confirms it. The body is low-slung and rounded, built for life close to the riverbed, and the mouth is set underneath for picking food off the gravel. The tail is clearly forked.
Run through this checklist with the fish in your wet hand:
- Barbels: two, one at each corner of the mouth.
- Markings: a row of 6 to 12 faint dark blotches along each flank.
- Colour: greenish-brown back, silvery sides and a white belly.
- Tail: forked, not rounded or square.
If you want a final check, a gudgeon has 40 to 45 scales along its lateral line. You won’t need to count them on the bank, because the barbels and blotches together settle it.
Colour varies from fish to fish, so trust the barbel count over the colour. If you are still unsure, the wider fish identification guide covers the other small fish you are likely to meet on UK rivers.
Gudgeon vs Stone Loach vs Minnow
You lift a tiny fish out of a shallow run and it could be any of three species. All three share the same gravelly water and look alike in a child’s net. One feature sorts most of them: the barbels.
| Feature | Gudgeon | Stone loach | Minnow |
|---|---|---|---|
| Barbels | 2 | 6 | None |
| Typical length | 7 to 15 cm | 6 to 10 cm | 4 to 10 cm |
| Typical weight | ½ to 5 oz (14 to 140 g) | under ¼ oz (3 to 6 g) | ¼ to ½ oz (8 to 16 g) |
| Colour and markings | Greenish-brown back, silvery sides, dark flank blotches | Mottled olive-brown | Olive-brown with dark bars and a dark stripe along the side |
The stone loach is the fish most often mistaken for a gudgeon, because both have whiskers. Count them: a loach has six barbels around the mouth, and its fins are rounded where the gudgeon’s tail ends in a fork. At well under ¼ oz (3 to 6 g), it is also far lighter.
The minnow has no barbels at all. Its flank shows dark bars and a stripe rather than a line of separate blotches. If you think you have a minnow, our minnow guide has the full detail.
The quick test: two whiskers plus a row of blotches means gudgeon.
How Big Do Gudgeon Grow?
A big gudgeon is still a small fish. The Wildlife Trusts give a typical length of 7 to 15 cm (about 3 to 6 in) and a weight of roughly half an ounce to just under 5 oz (0.014 to 0.14 kg). Other references put most adults at 9 to 13 cm, with exceptional fish reaching 21 cm, a little over 8 in.
Expect most of your gudgeon to sit toward the lower end of that range. Even a top-weight fish fits comfortably in your palm.
Gudgeon are also short-lived. The Wildlife Trusts give a typical lifespan of 3 to 5 years, and around 5 years is the usual quoted maximum.
Published figures for the British record vary between sources. The official list is kept by the British Record (rod caught) Fish Committee, so check their current list rather than trusting a weight quoted on a forum or tackle site.
Where Gudgeon Live and What They Eat
The shallow gravel run where gudgeon gather is worth watching for more than gudgeon. Plenty of other animals come to feed on them.
Gudgeon are widespread in lowland England and rarer in Wales and Scotland, according to the Wildlife Trusts. They are bottom-living fish of rivers and streams, often found over gravel or sand in shallow, steady runs. They can turn up in some canals and stillwaters, but rivers are the reliable bet.
They feed on small animals living on the riverbed, plus eggs and fry:
- mayfly larvae
- freshwater shrimp
- worms
- fish eggs and small fry
Gudgeon spawn in spring and summer, typically from April to August once the water passes about 13°C. The sticky eggs hatch in roughly 10 days.
Otters and kingfishers eat gudgeon, and predatory fish such as pike and perch take small fish of this size too.
The IUCN lists the species as Least Concern, so gudgeon are not considered threatened.
How to Catch Gudgeon
Gudgeon are easy to catch once you get two things right: a small bait, and that bait on the bottom. Get both right and a shoal will often keep biting while you keep feeding.
Start on a shallow gravelly run or steady glide on a river. Most anglers use a light float rod or a pole, set so the bait sits on the bottom or trips just over it.
Typical tackle and bait:
- Hooks: small, typically around size 18 to 22.
- Baits: a single maggot, pinkie or caster, or a small redworm.
- Feeding: loose feed a few maggots or pinkies little and often to hold the shoal in your swim.
Gudgeon are small and slippery, so wet your hands, unhook them quickly and slip them back. They are generally regarded as too bony to be worth eating, so almost all are returned.
For a child’s first session, a gudgeon run on a river is a good place to start, once you have checked the close season below. Then step up to bigger bottom feeders such as bream, silver bream or tench.
Gudgeon Fishing Rules in England
Most gudgeon live in rivers, which is where the close season applies.
Rod licence. In England you need a rod licence to fish for freshwater fish from age 13, according to the GOV.UK freshwater rod fishing rules. Check the current price there before you buy (fishing licence guide).
Close season. The coarse fish close season on rivers, streams and drains in England runs from 15 March to 15 June. Most enclosed stillwaters and canals can be fished all year (GOV.UK: when and where you can fish). Check local byelaws and club rules too (fishing seasons guide).
Live bait. Small fish such as gudgeon may only be used as live bait in the water they were caught from, and some local byelaws ban it. National byelaws apply, plus supplementary byelaws in six Environment Agency areas (GOV.UK local fishing byelaws).
These are England’s rules. In Wales, check Natural Resources Wales; in Scotland and Northern Ireland, check the relevant fisheries authority and permit holder.
Frequently asked questions
Are gudgeon good to eat?
Gudgeon are rarely eaten in the UK. They are small and bony, with very little meat, so almost all anglers return them alive to the water they came from. Wet your hands and unhook them quickly.
How long do gudgeon live?
Gudgeon typically live for 3 to 5 years, according to the Wildlife Trusts, and around 5 years is the usual quoted maximum. That makes the gudgeon a short-lived fish compared with most coarse species.
Are gudgeon rare in the UK?
No. Gudgeon are widespread in lowland England, though rarer in Wales and Scotland. The IUCN lists the species as Least Concern, so they are not considered threatened.
What is the British record gudgeon?
Published figures for the British record gudgeon vary between sources. Check the current British Record (rod caught) Fish Committee list for the official figure rather than trusting a weight quoted elsewhere. A typical adult gudgeon is 7 to 15 cm long and weighs up to just under 5 oz (0.14 kg).