The male queen parrotfish (Scarus vetula) is one of the most striking fish in the Carribean and happens to be my 2nd favorite fish. Females are a drab blue brown color while males are green-blue. This is an example of sexual dimorphism. Both sexes have plate-like beaks which give them the name parrotfish. They use these beaks to break off coral covered in algae. they then chew that mass and excrete the matter that isn’t algae. This process creates sand from the coral they ingest and is actually a major way in which sand is produced. This grazing also opens up space for coral to grow back in areas overtaken by algae. In areas without parrotfish reefs have been shown to shrink because coral can’t out-compete algae. They also feed on sponges and other creatures that may be attached to the reef. The fish is also known by the names blownose, blue chub, blueman, blue parrotfish, Joblin crow parrot, moontail, Okra peji, and slimy head. They are native to reefs in the Carribean, and thus also restricted to shallow water.
The fish breed throughout the year but typically restrict breeding to mornings. The fish exercise harem polygyny, which means that one male mates with a harem of females. They school in groups with one male and 3-4 females. However, the fish are also protogynous hermaphrodite which means that they can change their sex from female to male. In fact, all queen parrotfish are born as females. As they mature the largest in the school becomes male. The male that mates with the females is called a supermale and is identifiable by his bright coloration. The male chases the females and they swim in tighter and tighter circles until they release their gametes and the eggs are fertilized through external fertilization.