Male bettas are nicknamed Siamese fighting fish for a reason: They're very aggressive with one another and with female bettas. They are violent enough to lower their expected lifespans.

Betta fish—also known as Siamese fighting fish—are among the oldest ... He then puts on a display to attract a female, becoming brighter and spreading out his fins. If a female approves ...

Thailand alone exported about 20 million Siamese fighting fish in 2018, with major markets including the U.S., China, ...