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 (as the photo below shows). This minnow can be kept in captivity, yet is rarely sold as an aquarium fish.
This fish can be found in Scotland. The are common in fast-flowing, well oxygenated fresh water and in well drained ponds.