Monodactylus argenteus is a species of fish in the family Monodactylidae, the moonyfishes.

Its common names include silver moonyfish, or natal moony,[2] butter bream, and diamondfish.

[3] It is native to the western Pacific and Indian Oceans, including the Persian Gulf, Red Sea, and associated estuaries, such as the Mekong Delta.

[4][5] Juveniles are especially tolerant to salinity changes, easily maintaining homeostasis in variable environments such as estuaries.

[4] Although the silver moony displays territorial behavior,[2] the species can be kept in saltwater aquaria and is easy to rear in captivity.