Gudgeon has a rounded, elongated body with a slightly flattened belly and rather large scale-less head with an under slung mouth and thick lips. It has two barbules (one barbule either side of its mouth). Both dorsal and anal fins are short and heavily spotted. Colouration of the gudgeon is silvery blue or greeny brown on the back with a row of large, dark spots on the yellowish flanks.

Usually found in moving water such as rivers and canals.

All year round.

Gudgeon are bottom feeders and the barbules are used to search for food on the river bed. They are a shoal fish and are sometimes found in quite large shoals.

Widespread and fairly frequent in Britain, the records indicate that it is less common in the north.

Fairly frequent in Leicestershire and Rutland.