"Minnows" has generally come to mean any small, silvery, schooling fish. Technically, minnows are any fish in the family Cyprinidae, which includes several un-minnow-like fish such as goldfish, carp, and rainbow shark. Many small, schooling fish, whether Cyprinidae or otherwise, are popularly kept in home aquariums. A well-chosen school of minnows is sure to add movement and colour to your freshwater fish tank.
White Clouds and Rosies
The white cloud minnow is actually extinct in the wild, but it is a popular, peaceful schooling fish which thrives in aquariums. The white cloud has white colouring with yellow lines but may also come in a long-finned or a golden variety. White clouds lived in fast-moving streams and are ideal for cool water fish tanks. Rosy red minnows, also called fatheads, are often sold as "feeder" fish, but a group of them can make a nice addition to an aquarium.
Danios, Barbs, and Rasboras
Zebra danios are popular aquarium minnows. They have silver or gold colouring with bright blue or purple lines. Other varieties of danio include the blue danio, the glowlight danio, and the giant danio. Barbs and rasboras are also minnows available in a variety of colours and sizes for the aquarium trade. These fish do well in tropical, community tanks. Rasboras, barbs, and danios are by far the most popular minnows found in home aquariums.
Gambusia, or mosquito fish, are quintessential silver minnows which thrive in a variety of water temperatures and conditions. They even survive in brackish or saltwater. Despite their hardy and active nature, they are underutilised in aquariums due to their lack of vibrant colours. However, they are popular pond fish because they will voraciously consume mosquito larvae. Gambusia can be slightly aggressive with its own kind and others, so smaller shoals of three to five fish are advised within a home aquarium.