Monodactylus argenteus is a species of fish in the family Monodactylidae, the moonyfishes. Its common names include silver moonyfish, or natal moony,[1] butter bream, and diamondfish.[2] It is native to the western Pacific and Indian Oceans, including the Persian Gulf, Red Sea, and associated estuaries, such as the Mekong Delta.[1]
This species reaches a maximum length of about 27 centimeters. It is bright shiny silver with yellowish edges to the fins.[1] The dorsal and anal fins have black tips.[2] Juveniles have more yellow coloration[1] and are distinguished by two vertical black bands.[3]
This species occurs in a wide variety of habitat types, including the open ocean, brackish waters, and the freshwater habitat of rivers.[1] In Australia it can be found in harbors and estuaries around piers.[2] Its ability to survive in a wide range of salinities makes it a model organism in the study of salinity tolerance.[3] [4] Juveniles are especially tolerant to salinity changes, easily maintaining homeostasis in variable environments such as estuaries.[3]
Although the silver moony displays territorial behavior,[1] the species can be kept in saltwater aquaria and is easy to rear in captivity.[4] It can remain solitary or form schools. It is a detritivore and planktivore.
The myxozoan parasite Kudoa monodactyli was first described from and named after this fish.[5]