Minnow

By Alex Clayton · Updated 23 October 2026

Plenty of people call any tiny fish a minnow, but the common minnow is a species in its own right, and an adult rarely grows past 10cm. The minnow fish (Phoxinus phoxinus) is a small member of the carp family that shoals in clean, well-oxygenated rivers and streams across Great Britain. Most weigh 8 to 16g.

Because it stays so small, it is easy to confuse with young fish of other species. This guide to the minnow in the UK covers identification, habitat, spawning, catching them, the British record and the rules on using them as bait. For bigger targets, see our guides to other UK coarse fish.

How to Identify a Minnow

One check settles the commonest mix-up at the net: look along the fish’s back for spines. A minnow has none. A stickleback does, and that single difference separates the two small fish you are most likely to scoop out of a stream.

Once the spines are ruled out, check these features:

Feature	What to look for
Size	Usually 4 to 10cm. FishBase gives a common length of about 7cm and a maximum of 14cm
Back	Olive-brown with dark bars
Flank	A dark stripe running along the side
Belly	Silvery on females, pinkish-red on males in summer
Back fin	Soft, with no spines

The breeding male is the easiest to pick out. In summer his belly turns pinkish-red, and that flash of colour is often the first thing a child notices in the shallows.

Sticklebacks, gudgeon, bleak and the fry of roach, dace and chub all get mistaken for a minnow fish. The spine check only rules out the stickleback. For the rest, our fish identification guide compares them side by side.

Under 10cm, barred on the back, striped along the side and no spines: treat it as a minnow.

Where Minnows Live in the UK and What They Eat

A shoal of fish no longer than your finger can tell you something about a whole river, because minnows are fussy about water.

The common minnow needs clean, well-oxygenated water. It lives mainly in rivers and streams and turns up less often in lakes. Look for shoals in shallow runs and along the margins, where the water is clear and moving. From April to June, check shallow gravel too, where they gather to spawn.

FishBase lists minnows as native across Great Britain up to about 58 degrees north. Because they need clean water, a healthy shoal is a good sign for a stream. It is not a formal water quality test, but where minnows thrive, the water is usually in reasonable shape.

Minnows eat:

insects
molluscs
crustaceans
plant debris
fish eggs

In turn, they feed brown trout, kingfishers, herons and otters. Where minnows are plentiful, predators follow.

Minnows are mainly a running-water fish, which sets them apart from species such as tench that favour still and slow-moving water.

Minnow Spawning, Breeding Colours and Lifespan

A fish this small can spawn several times in one season and lay up to 1,000 eggs.

Minnows make a short move upstream to shallow gravel to breed. They spawn several times between April and June, and the eggs stick to the gravel. This is when the males show the red bellies described in the identification section above.

Most minnows live for 2 to 5 years, according to the Wildlife Trusts. FishBase records a maximum reported age of 11 years, which is an exceptional fish rather than a typical one.

Spawning gravels are easily disturbed, so where you can, avoid wading through shallow gravel runs in late spring. The spawning period also overlaps the river close season in England, covered in the rules section below.

Catching Minnows: Bycatch, First Fish and the British Record

You are float fishing a small river for roach or dace, and the float keeps dipping to fish no longer than your finger. That is usually minnows.

Few anglers set out to catch a minnow fish, but minnows take tiny baits readily. They turn up as bycatch on the smallest hooks and in hand nets in the shallows, which often makes them a child’s first fish.

If minnows are getting in the way, step up to a bigger bait on a bigger hook. They will still peck at it but rarely get hooked.

Handle them with wet hands, unhook them quickly and return them straight away. Small fish are fragile.

The British record minnow weighed 13.5 drams (0.024kg), a little under an ounce, caught by J Sawyer at Whitworth Lake, Spennymoor, in 1998, according to the British Record (Rod Caught) Fish Committee list. Some sites credit the record to the River Exe. The official list does not.

For something that pulls back harder, try bream or silver bream. A minnow on the hook is a sign of a healthy river, not a nuisance.

Using Minnows as Bait: What the Rules Say

A bucket of minnows from the local brook, tipped out as bait at the lake down the road, breaks the byelaws.

In England, the national rod fishing byelaws allow live bait, but you must keep bait fish at, and only use them in, the water you took them from. Some local byelaws ban it outright. Moving any fish or spawn between waters needs written Environment Agency agreement, because moving fish can spread disease.

GOV.UK’s tackle rules for England and Wales say the same, and also ban crayfish as bait.

You need a rod licence from age 13 to fish with a rod in England and Wales. For hand nets or traps, check GOV.UK first.

The English coarse close season runs 15 March to 15 June inclusive on rivers, streams and drains, most SSSI stillwaters, some canals and most Norfolk and Suffolk Broads waters. In Wales, Natural Resources Wales sets no close season on stillwaters and canals (except certain SSSIs); other waters open 16 June to 14 March.

Nation	Minnows as bait	Where to check
England	Same water only, unless a local byelaw bans it	GOV.UK
Wales	Same-water rule applies	Natural Resources Wales
Scotland	Check before you fish	Scottish Government or District Salmon Fishery Board
Northern Ireland	Check before you fish	DAERA (Loughs Agency in Foyle and Carlingford)

To use minnows as bait, catch them on the day from the water you are fishing, and check the club or fishery rules first, because some ban live bait.

Frequently asked questions

Are minnows baby fish?

No. The common minnow is a species in its own right and stays small as an adult, usually 4 to 10cm. Young roach, dace or chub can look similar, so check for the barred back, the dark side stripe and the lack of back spines.

How big do minnows get?

Usually 4 to 10cm and 8 to 16g, with FishBase giving a maximum length of 14cm. The British record is 13.5 drams (0.024kg), caught by J Sawyer at Whitworth Lake, Spennymoor, in 1998.

Can you use minnows as live bait in the UK?

In England and Wales, only in the water you caught them from, and in England some local byelaws ban it. Moving fish between waters in England needs written Environment Agency consent. In Scotland and Northern Ireland, check with the Scottish authorities or DAERA before you fish.

What do minnows eat?

Insects, molluscs, crustaceans, plant debris and fish eggs. In turn, minnows are eaten by brown trout, kingfishers, herons and otters, which is why predators gather where minnows are plentiful.