The development of parrot fish is complex and accompanied by a series of changes in color termed polychromatism. For most species, adult males and females have different color, the females usually displaying drab tones of green, brown or gray, and the males a vivid, neon color. In the Mediterranean parrotfish (Sparisoma cretense), it is the females that have neon color with the males being a drab gray. ParrotfishIn most species, the juveniles have a different color pattern than the adults and some tropical species this juvenile coloration can be altered temporarily to mimic the appearance of other species. As the juveniles mature they enter what is termed the initial phase coloration during which they may change color and gender. For most species, initial phase fish are usually males that have the beginnings of the adult male coloration. However, initial phase fishes may include generally mature females. The many varieties of color the parrot fish has presented to us are all part of the many phases the parrot fish goes through. Feeding parrot fish of most tropical species form large schools grouped by size. Fights of several females presided over by a single male are the normal in most species, the males vigorously defending their position at any challenge. If the dominant male of a school is removed, one of the females will change gender and adopt the dominant male role. Parrot fish are pelagic spawners; that is, they release many tiny buoyant eggs into the water which become part of the plankton. The eggs float freely, settling into the coral until hatching.

A commercial fishery exists for some of the larger tropical species. Their meat is rarely consumed in the US; however, it is considered a delicacy in many other parts of the world. Protecting parrot fish is proposed as a way of saving Caribbean coral reefs from being overgrown with seaweed. Although any good Phuket dive shop is strongly against fishing on these reefs they are around in huge numbers and they are a great quality meat. But again they do keep the reefs clear of weed and stop the reefs from choking. large numbers can also chew through vast areas or coral in a very short time if the delicate balance is disrupted too much.

A number of parrotfish species, including the Queen parrotfish (Scarus vetuala) excrete two different mucus types during day and night. Prior to going to sleep each night, the parrotfish extrudes mucus from its mouth, forming a protective cocoon that envelopes and secures the fish at a particular location and hides its scent from any predators. It also acts as an early warning detection system, allowing the parrotfish to flee, when it detects its protective membrane is disturbed by predators, such as a moray eel. The mucus also has antioxidant properties to repair any bodily damage and to repel any parasites, which when produced during the day, provides added protection for the parrotfish from UV light.