This goldfish has a rounded body and two tail fins. Just like the name implies, this fish has super long, flowy fins. Moors have big bug eyes. Another hardy coldwater aquarium fish is the weather loach. This long, snakelike fish is brown or bronze with brown markings, and will grow to be three to four inches.
More experienced caretakers can select fish that live in warm water.
There are hundreds, if not thousands, of warmwater tropical fish sold as aquarium pets. The hardest, and most important, part is selecting fish that will do well in the same type of water conditions and will get along with each other. Watch them do some synchronized swimming back and forth across your aquarium, flashing their colors all the while. Quick-moving danios like to hang out in schools, too. They are one to two inches long.