Mandarin fish are reef dwellers, preferring sheltered lagoons and inshore reefs. While they are slow-moving and fairly common within their range, they are not easily seen due to their bottom-feeding habit and their small size (reaching only about 6 cm). They feed primarily on small crustaceans and other invertebrates. Based on the gut analyses of 7 wild fish Sadovy et al. (2001) determined that the mandarinfish has a mixed diet that consists of harpacticoid copepods, polychaete worms, small gastropods, gammaridean amphipods, fish eggs and ostracods. In the wild, feeding is continuous during daytime; the fish peck selectively at small prey trapped on coral substrate. We offer a continuous automatic live food source for you and your new Mandarin.

Despite their popularity in the aquarium trade, mandarin fish are considered difficult to keep, as their feeding habits are very specific. Some fish never adapt to aquarium life, refusing to eat anything but liveamphipods and copepods (as in the wild or from FloridaPets.com); though individuals that do acclimatize to aquarium food are considered to be quite hardy and highly resistant to diseases such as marine ich. They are less likely to contract marine ich because they do not have the typical skin type that is affected by this disease. Mandarin fish also have a layer of smelly and bitter slime instead of scales, which blocks out disease and also discourages predators.