Monos Fingerfish, monodactylus argenteus, are members of the family Monodactylidae. They are native to the coastal areas of the Indio-Pacific, western Africa and Australia. These shallow water dwellers are not initially true saltwater marine species. They frequent the brackish water found in sheltered lagoons and inshore reefs when young. Juveniles can even survive in freshwater environments.

Monos are medium to large sized triangular shaped fish. Their bodies are distinctly similar to those of freshwater angelfish. The two are not in anyway related. They have white to silverfish bodies and frequently have two black vertical stripes on the anterior region of their body. This vertical striping accentuates the similarity between them and their freshwater look-alikes. Juveniles are further accented with yellow trimmed fins. This coloration vanishes with age. They can reach a maximum adult diameter of 9 inches.

This is a shoaling fish. Communal instinct runs high in this species. It is inadvisable to attempt to keep a solitary mono. You will want to have a minimum of four monos in your aquarium. Given their size you will require at least a 55 gallon tank for a mono-species setup and 100 gallons or more if you wish to keep them in a community tank. They are very active mid-level swimmers and will require plenty of wide open spaces. Monos have a life expectancy of up to 10 years of age in captivity.

The juveniles of this species demonstrate prevalence for brackish water. As already stated they can survive in a freshwater environment provide it is hard water with a high mineral ion content and an alkaline rather than acidic base. As monos mature they will venture further away from brackish water until they become a true saltwater species. If you are keeping these fish in a mono-species aquarium you will want to increase the salinity level as they mature. It should be apparent that only more mature members of this species should be added to a community saltwater tank.

Monos are moderately aggressive fish. Juveniles are timid in nature. These fish becomes more aggressive with size. They will never become assertive enough to be housed with truly aggressive species.

Mono fingerfish are omnivores with voracious appetites. They are not picky when it comes to their eating habits in captivity. They will eat live foods, frozen or freeze-dried foods and flakes or pellets formulated for omnivores. They will even nibble on freshly chopped vegetables if given the opportunity.

There is no visible difference between the males and females of this species. There are no reports of monos being successfully bred in home aquaria. However they are commercially tank-bred and raised on fish farms in Florida and parts of the Far East.

A commercially bred fish is always a better alternative to a fish captured in the wild. Farm raised fish are often half the price and have up to a three times higher survivability rate. Farmed fish tend to be more uniform in size. Your local fish store or any reputable online retailer will be able to tell you if their stock is wild or captive bred.