In the long run, several species of fresh water fish, such as the zacco and the smelt, can simply not compete with the Tilapia, which eats anything and protects its eggs. It is of such strength that NASA of the United States has selected it as "a fish for use in outer space."
國內許多淡水魚種如溪哥、香魚根本無法與什麼都吃、有護卵能力、甚至因生命力強而被美國太空實驗室選為「太空用魚」的吳郭魚一較長短，族群漸失。