Have you ever had a betta fish?
Betta
Betta, is a large genus of small, often colorful, freshwater ray-finned fishes, known as "bettas", in the gourami family (Osphronemidae).
The best known "Betta" species is "B. splendens," commonly known as the Siamese fighting fish.
Characteristics.
All the "Betta" species are small fishes, but they vary considerably in size, ranging from under 2.5 cm (1 in) total length in "B. chanoides" to 14 cm (
not dependent on high oxygen levels in the water, so a large surface area for gas exchange is not required.
Some Betta enthusiasts will claim that there is a minimum tank size for a Betta, but to try to set a strict baseline minimum is arbitrary and akin to the mythology of one inch of fish per US gallon rule.
Many consider 2.5 - 5 US gallons(9-19 liters) to be an ideal tank size for a Betta, "but you can successfully keep a Betta in a 1 gallon tank