Betta Fish

No list of colourful fish would be complete without mentioning betta fish. The most popular species is Betta splendens because they come in almost every shade imaginable and have a multitude of tail shapes as well. Because they have a labyrinth organ that allows them to gulp air from the surface, some people think they can live in a cup-sized container or vase for the rest of their lives. Instead, we recommend putting them in a 5-gallon tank or bigger that has an aquarium heater and gentle filtration like a sponge filter. Because of their aggressive nature, not all betta fish can have tank mates, but if yours has a chill personality and you want to try it, then consider upgrading to a 10- or 20-gallon tank with lots of cover and live plants to block line of sight. 

Electric Blue Acara

Speaking of South American cichlids, the blue acara is a 6- to 8-inch (15–20 cm) fish that can be relatively peaceful and live in a community tank with larger tank mates. The electric blue variety is a special colour morph of this species and is known for its bright, neon blue body with hints of orange and gold on the fins and scales. Unlike most cichlids of this size, they are not overly destructive and can be put in a 50-gallon tank or bigger with aquatic plants. Feed them high-quality cichlid pellets, frozen foods, worms, and other meaty foods. 

Fancy Guppies

Another of the classic aquarium species, the guppy, has been part of the aquarium hobby for over 100 years. Today, there are many different fin and colour strains that have been selectively bred for many generations. While an aquarium with dozens of fancy guppies can be beautiful, most people only keep a few at a time in which then they are likely to earn their name. Their constant swimming behaviour, gregarious nature, and bright colours will endear them to many hobbyists. Many strains produce uniquely coloured individuals which can make for quick recognition of particular fish, a trait that is very important for “naming”. Their active swimming can take up a lot of energy.