Head to head
Topmouth Gudgeon vs Gudgeon
Topmouth Gudgeon
VS Gudgeon
The topmouth gudgeon and the gudgeon share a name and a small size, but one is a native of European rivers and the other an invader from eastern Asia.
| Topmouth Gudgeon | Gudgeon | |
|---|---|---|
| Scientific name | Pseudorasbora parva | Gobio gobio |
| Relationship | A small fellow member of the carp family | A small fellow member of the carp family |
| Origin | Native to rivers and lakes of China, Japan, Korea, and the Amur basin in eastern Asia | Native to rivers and lakes across Europe and northern Asia |
| Size and mouth | Usually 6 to 9 cm long, with an upturned mouth that gives it its name | Usually 10 to 15 cm long, rarely more than 20 cm, with a pair of short barbels at the corners of its mouth |
| Where it feeds | Eats zooplankton, insect larvae, small crustaceans, plant material, and the eggs of other fish | Feels along the bottom for insect larvae, small crustaceans, snails, and worms in the sand and gravel |
| Behaviour and breeding | The male defends a nest site, usually on the underside of stones or submerged objects, and guards the eggs fiercely | Lives in shoals over sand and gravel, where its speckled body is well camouflaged |
| Effect on others | Carries a parasite called the rosette agent, which can infect and kill native fish such as salmon and trout, and is hard to eradicate | Eaten by larger fish and by birds, and long used as a bait fish |
| Conservation status | Least Concern in its native range, and invasive across much of Europe, where it is the target of control efforts | Least Concern, widespread and common across a large range |
Topmouth Gudgeon vs Gudgeon: common questions
Is the topmouth gudgeon a native of Europe?
No, it is native to eastern Asia, and was accidentally introduced to Europe in the 1960s with shipments of Chinese carp.
Why is it a problem?
It breeds quickly, spreads easily, competes with native fish, and carries a parasite that can infect and kill native species.
How can you tell them apart?
The topmouth gudgeon has an upturned mouth and is smaller, while the gudgeon has a pair of barbels at the corners of its mouth and a row of dark blotches along its side.