Gudgeon - matchman's makeweight Gobio gobio

Although tiny and the bane of many an angler, the gudgeon doesn't deserve the bad press it gets - it can save you a blank day and often forms the basis of match anglers' winning catches

A slender, silvery blue fish, it has dark patches along the flanks and black spots on its tail and dorsal fin The scales are large, numbering 40 to 45 along the lateral line The gudgeon looks quite similar to a small barbel, but you can distinguish the two by counting the whiskers - gudgeon have one pair while barbel have two.

As its flattened belly and short barbels at the corner of the mouth suggest, the gudgeon feeds on bottom-living insect larvae, crustaceans and molluscs It can extend its mouth into a tube which it uses to suck up invertebrates hiding in the spaces between the gravel - rather like a vacuum cleaner.

Gudgeon thrive in rivers and streams with a gravelly bed, but are also prolific in canals and can be found in lakes Though not very common, they grow especially large in gravel pits

They live and feed in tightly packed shoals In the summer they gather in the shallows but with the onset of winter, they retreat to deeper, slacker water where they rest, feeding little

The gudgeon becomes sexually mature at two or three years old It spawns from May to June over stones and weed in shallow water The male develops small white tubercles on its head and shoulders and rubs them along the female's flanks during courtship -probably to stimulate her to release eggs.

The female takes several days to lay between 800 and 3000 eggs in two or more batches. As this is a big effort for such a small fish, it only usually manages to spawn for two to three years before dying

The fry hatch after a couple of weeks Strong year classes are produced in hot summers since the fry can develop quickly when the water temperature is 12°C (54°F) or higher This is also true for chub in rivers and tench, carp and bream in lakes However the gudgeon's annual growth is slow compared with that of barbel and roach Most gudgeon take five years to reach a length of 15cm (6in) - only a few individuals survive to grow larger or live longer than this.

In France the gudgeon is a favorite table fish and in central Europe it is fed to pigs - but in Britain it is carefully returned to fight another day

Gudgeon fishing picnics in punts on the Thames were very popular in the 19th century Gravelly shallows were raked to attract the fish to feed and then light tackle with a small redworm for bait was used to catch them In the same century, bathers at Bath spa were given plenty of gudgeon to eat because it was thought they helped digestion.

The following selection of rivers and canals is recommended for catching gudgeon -though you will find them in fair numbers in many, many waters throughout England, Wales and Ireland

Around Banbury, Oxfordshire

Trent and Mersey Canal Willington, Derbyshire

Staffordshire and Worcester Canal around Stafford

Grand Union Canal Near Rowington, Warwickshire

River Trent near Burton Joyce, Nottinghamshire

River Soar Around Loughborough, Leics

Fish facts: Weight: Up to just over 112g (4oz), average 14-28g (1/2 - 1oz)

Length: Up to 20cm (8in)

Life-span: 5-8 years

Favorite waters: rivers and streams with gravelly beds and canals

• The gudgeon has large scales and a silvery-blue back with dark brown patches along the flanks The dorsal fin and tail also have numerous brown spots

• The flat belly is suitable for life on the bottom

• The bottom-feeding gudgeon has a barbel at either side of its mouth These whiskers contain taste buds which the fish uses to detect and taste food

• The mouth can be extended into a tube to suck up invertebrates.

The current British record is held by D H Hull In 1990 he caught a 141g (5oz) fish from the River Nadder, Salisbury, Wilts

There are no gudgeon records for Ireland, but the qualifying weight for a record gudgeon in Scotland is 112g (4oz) - a record that is extremely unlikely to be claimed since this species of fish is very scarce north of the border

Gudgeon live in closely packed shoals which thrive in rivers and streams with a moderate flow and also in canals

In winter the fish retreat to deeper, slacker water and feed little

During the summer they move to the shallows to feed on invertebrates, especially molluscs.