Both are correct, Mandarin fish and guppy fish refer to the same fish. They refer to fish in the genus Siniperca in the order Perchiformes of the order Scleractinia. There is no difference between Siniperca chuatsi and Gui fish, just different names. Gui fish is the common name of Mandarin fish, Mandarin fish is the scientific name of this fish, but because the word "Mandarin" is more remote, many anglers only know how to read, but do not know how to write, so the word "Gui" instead of the word "Gui", and over time a lot of places, they will be Mandarin fish called Gui fish, Gui fish, Mandarin fish and Gui fish is just a difference in the way to call.