Below are a few ideas of fish species that you might like to keep in your aquarium, and where they generally like to spend their time. These fish cannot necessarily be kept together - and growing sizes would need to be taken into consideration (see – How many fish?) - but these are few ideas to get you inspired.
Betta, otherwise known as Siamese Fighters, are very attractive fish that come in many colors - commonly blue or red. The males have impressive, long fins but are territorial and should be kept alone, or only with females. Never keep two males in the same tank and avoid keeping with fish that like to nip fins. Adult size (without fins) up to 3".
Guppies are colorful, fun, active little fish that will liven up a community aquarium. The males are more colourful with bright fins and tails, available in a rainbow of colors - sometimes patterned. These fish are livebearers, meaning the females give birth to live young rather than laying eggs. Keep males and females together and you'll soon have new additions to your aquatic family. Guppies come in various sizes but can grow up to 2.5"
Extremely popular aquarium fish, the Cardinal Tetra loves to live in shoals. Invest in a small shoal and you will be rewarded with their appearance in the center of the tank. They also enjoy planted areas to hide on occasions, but more importantly is good water quality as they do not tolerate poor water conditions. Adults grow to around 2".
Cherry Barbs are gregarious little fish and are popular for the community aquarium. Keep a mixed shoal in a planted aquarium and you'll be rewarded with interesting social behaviour. Adults are colorful, the male a deep red and the female more brown in tone. Adult grow up to 2".
Corys are bottom dwelling catfish that like to root around on the top of the substrate for food. These are shoaling fish so like to have the company of other Corydoras, although it does not need to be the same species. There are a variety of species available in different patterning, colors and sizes. The image shows a Corydoras Panda that can grow to over 2", but smaller varieties suited to a smaller aquarium include: the Salt and Pepper Cory, Pygmy Cory and the Dwarf Cory.
As well as color and interest, shrimps can add a touch of humor to the aquarium as they pick about for bits to eat in the gravel and on rocks and plants. As with fish, there are a variety of shrimp species suitable for the tropical aquarium, a couple of examples being the Crystal Red Shrimp (above) and the Amano Shrimp.
Some snails are known pests of the aquarium, however there are species that are kept for their interest and their ability to munch on algae build-up on leaves, glass and decor. As with fish and shrimps, there are several varieties suited to the tropical aquarium.