First of all some numbers: the parrotfish family count 95 different species and 16 of them can be found in the Caribbean. The majority reach between 30–50 cm in length. A few species can reach lengths up to 1.3 m and weight up to 25kg for example the humphead parrotfish found in the indo-pacific ocean and the rainbow parrotfish (see picture number 1) foundhere on the Caribbean, lot of sittings in Cozumel and also on Tortuga reef in Playa del Carmen.
Parrotfish are among the most colourful species of reef fishes and therefore often loved by divers. ‘Beach people’, non divers people do not know but they should also love them, for what? Because they are responsible for the beautiful thin white sand of most of the tropical beaches around the world!! HOW?
Unlike a lot of people think, parrotfish do not eat the coral, they are mainly herbivorous and scrape off the algae from dead coral or rocks. They do that using their hard teeth fusioned as a beak (see picture number 2) its actually from where they get their name from! Chunk of dead coral or rocks are often ingested among the algae and after the digestion of their meal the inorganic part is excreted as sand. Yeah the nice white sand is actually Parrotfish poo ;). They add many tons of sand to our beach every year the average of sand expelled per individual is estimated around 70 kg per year!
As algae and corals are often competing for spaces on the reef, the parrotfish grazing on algae are helping the reef to maintain a equilibrium and stay in a good health. Among algae some species also include in their diet small invertebrates, sponges and detritus.
Now lets tell you more about their capacity to change sex and color:
Most of the species of parrotfish are hermaphrodite which means that there are able to change sex during their lives. In the majority of the species they start their lives in a female juvenile stage presenting gray tons of color parrotfish (picture 3). Then at sexual maturity they turn into what is called an initial phase presenting brown/redish colors (picture 4).Some of them are lately going to transform into a terminal phase, they change sex and color and become males with bright blue/green tons (picture 5).
In some species some are born male and will stay male all their lives, they usually present differentmating strategy and have keep the color of the initial phase.
They tends to live in harem with one male for several females and if the male die or leave the harem, one of the female (usually the biggest) will change sex and color to replace him. They also use color changes to communicate and hide from predators by matching their surroundings. Those changes are less noticeable usually appearing more like a change of the intensity of the colors.
To end this article a last interesting fact about the parrotfish: at night time before sleeping they are secreting a mucus cocoon around themselves protecting from parasites and eventual predators!
Hope you learned something in this article, as you see besides being beautiful parrotfish are really interesting animal full of surprise ! All pictures expects from the mucus one as been taken here in Playa and Cozume by me ^^.