Arctic charr in Wales, named locally as the torgoch or ‘red belly’, is an iconic wildlife species of the region. These spectacular and colourful lake dwelling fish are closely related to salmon and trout and are a fascinating relic of the last ice age. There are only three lakes in Wales with native populations of Arctic charr, and they are all located in the northern mountainous region of Snowdonia.

Unlike most other fish native to the British Isles, Arctic charr are highly effective in exploiting the deep, open waters of nutrient deplete upland lakes, and thus fulfil a unique and vital ecological role, reflected in their designation as a biodiversity priority species for the UK.

Yet despite their recognised value, populations in the British Isles are in general decline due to various anthropogenic disturbances.

The pike is a large fish that can grow over a metre in length. It is found in lakes and slow-flowing rivers and canals that have a lot of vegetation. It uses these plants as hiding places when hunting, bursting out with remarkable speed to catch fish, frogs, small mammals or ducklings. Young pike are called 'jack' and will eat small fish and invertebrates. Pike spawn between March and May, returning to the same place every year. A large female can produce up to 500,000 eggs.

Eels are born in the Sargasso Sea, within the Atlantic Ocean. After about three years swimming the Gulf Stream, they reach the UK and Europe as tiny transparent elvers known as glass eels. Here they gradually mature, becoming a darker green/brown in colour with a silvery belly. They inhabit most waterbodies and may even crawl over flooded land to access pools unconnected by streams or ditches.

They prefer dark and heavily coloured waters, or waters with plenty of silt and mud at the bottom. They mainly feed at night and generally scavenge for food, preying on dead and dying animals, fish and invertebrates. At between 8 to 18 years the mature eels then head back across the Atlantic to the Sargasso Sea to spawn.

The Minnow (Phoxinus phoxinus), in the time of spawning the tiny silver brown male devolops spectacular colouring. The back becomes dark, the sides golden and the belly and fins become bright red. They are the most abundant British Freshwater fish, inhabiting gravelly streams. Grows up to 4 inches long. It is ubiquitous throughout much of Eurasia, from Britain and Spain to eastern Siberia, predominantly in cool (12–20 °C) streams and well-oxygenated lakes and ponds. It is noted for being a gregarious species, shoaling in large numbers