The huge range of ornamental fish available makes it far from easy to find the right species when you first start out. Pet retailers will assist you. They know which species will live together peacefully and may initially recommend more robust species that will not be affected too much by minor errors. These could possibly be in the form of live-bearing fish, i.e. fish that give birth to live young rather than laying eggs like other fish. Examples of such species include guppies and platies. A shoal of neon tetras can look beautiful in a large aquarium or your pet retailer may recommend a fighting fish that builds interesting foam nests on the surface of the water.
Whereas some species of fish like live-bearers have a relatively short lifespan of maximum three years, tetras like the neon can live for five or more years. Large catfish survive for several decades and the somewhat smaller cory can still reach an age of 10 years.
Source: Tetra
