A fighter fish (betta fish) can reach up to the length of 6.0 centimeters. Some sub-species can even reach 8.0 centimeters. Now, because of the mutant gene, the breeders can make a betta to grow beyond 8.0 centimeters.
The fighter fish are usually of dull green and brown colors. Though they have flowing fins, the wild specimens of fighter fish have relatively short fins. But the breeders have been successful in developing brightly colored and longer finned types of bettas.