Betta fish—also known as Siamese fighting fish ... and are a dull gray, green, olive, or brown. Before mating, the male spends hours blowing bubbles at the water’s surface to build what ...

Betta, or Siamese fighting, fish are among "the most popular freshwater aquarium fish in the world," PetMD reports. Native to southeast Asia, this species is known for its range of vibrant hues.