What is a betta fish? Betta fish—also known as Siamese fighting fish—are among the oldest species of domesticated fish. Their scientific name, Betta splendens, combines two languages ...

We may receive a commission on purchases made from links. There are over 70 species of betta fish, with the most common pet varieties being the crowntail, delta, double tail, and halfmoon.

Scientists have found Siamese fighting fish are typically kept in containers just one-quarter the size they need to thrive, challenging decades of retail practice in the ornamental fish industry ...