Freshwater Fish of the Uk – Filmed Underwater – How to Identify Them!

In this video we look at how to identify some of the common freshwater fish that live in the UK, Including Pike, Chub, Roach, Gudgeon, Minnows and Perch.
The Eurasian minnow is the smallest species that features on this list, growing to a maximum length of just 10cm and a top weight of just 16 grams. Their bodies are torpedo shaped and they have a dark line running down each side from their heads to the base of their tails. In the spring and summer, male minnows that are in breeding condition become a darker colour and may have dull red patches at the base of their fins and under their chins. They are found all across the UK, usually in streams and rivers but also in standing water such as lakes and ponds. Minnows are omnivores, with their forward-facing mouths they take food from the surface, from the sediment and from in the water column. This food includes, insects, crustaceans, plant matter and both their own and the eggs of other fish.


Northern Pike can grow to almost five feet in length and to more than 20kilos in weight. They are ferocious predators, equipped with a paddle shaped tail that allows them to burst through the water at high speed to catch their prey. This prey can include mammals, water birds, other fish and sometimes they will even eat each-other. They are well camouflaged and lurk in amongst aquatic vegetation, using their large eyes to spot unsuspecting prey before snatching it with their mouths full of razor sharp teeth.
Another predatory freshwater fish is the Perch. These are much smaller than pike, growing to around 30cm and weighing upto 3 kilos. Perch have tiger-like stripes running down their bodies and Their dorsal fin which stands high on top of their backs, is notoriously spiny. When perch are young they live in small shoals, feeding on invertebrates and crustaceans but as they get bigger they become more solitary and start to take larger prey, such as amphibians and small fish. Perch are found across the whole of the UK and are common in canals, slow flowing rivers, lakes and ponds.
Gudgeon are a familiar species to many anglers, as they are the first fish that most people catch when they start out. Gudgeon only grow up to around 15cm and to less than 90 grams. They have downturned mouths and spend most of their time searching the sediment for food. They are very common across England but only sparsely recorded in Scotland, wales and their have only been a handful of confirmed records in northern Ireland.
Roach are a rather standard shaped silver fish. They have orange eyes and fins and are common in lakes, ponds, ditches and slow flowing rivers. They can grow to length of around 35cm and the largest ever recorded in the UK weighed just over 2kilos. Roach sometimes form massive shoals of similarly sized fish, especially in winter. They have an omnivorous diet that includes invertebrates, crustaceans and aquatic vegetation. There are a few freshwater fish that look similar to roach including the Rudd which is almost identical but has an upturned mouth, unlike the roaches which is downwards facing.


Chub are found in flowing water across all of mainland Britain but are absent from northern Ireland. They are streamlined in shape and have a very large mouth which they use for grabbing food as it drifts by in the current. Small Chub eat mainly invertebrates and vegetation but they can get to more than 40cm in length and larger fish often become more predatory. Eating crayfish, amphibians and other small fish. Chub have a dark outline to their tail and dorsal fin which can be seen from above the surface and sets them apart from other similar looking species.

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