Tropical Fish Breeds and Species Guide

Understanding species differences

There is no single care routine that suits every tropical freshwater fish. Species differ in adult size, preferred temperature, water hardness, swimming area, diet, social behaviour and compatibility. OATA provides separate care sheets for groups including tetras, rasboras, guppies, mollies, gouramis, bettas, catfish, loaches and cichlids. A species guide should therefore be used as a comparison tool, followed by species-specific research.

Water and social needs

Adult size is particularly important. A fish that is small in a shop can grow considerably, and RSPCA warns that some fish become very large and are unsuitable for many home aquariums. Water parameters also matter: choosing species that fit your local tap water can make long-term maintenance^★ easier. Never assume that visually similar fish have identical requirements.

Comparing suitable fish

Social behaviour must be checked before mixing species. RSPCA notes that many shoaling tropical fish need groups, while other species can fight with their own kind or other fish. Compatibility includes temperament, adult size and water conditions. The best species list is one that can live together in a suitably sized, cycled aquarium without forcing any fish into unsuitable conditions.