Queen Parrotfish

• By grinding up the coral skeleton to digest the algae it produces sand: a single large parrotfish can generate hundreds of kilos of beach sand a year.
• At night it wraps itself in a cocoon of mucus secreted from its mouth, which masks its scent from predators and parasites.
• It is a protogynous hermaphrodite: all are born female, and the dominant individuals turn into males, changing colour completely in the process.
• It sleeps inside a sac of slime. At dusk it slips into a crevice and secretes, from glands behind its gills, a bubble of mucus that envelops it completely within half an hour.
• That cocoon is not just a blanket: it carries antibiotics that kill pathogens specific to parrotfishes and physically blocks blood-sucking parasites. It is built from a mesh of glycoproteins linked by disulphide bridges.
• It makes sand. It scrapes algae and coral with its beak of dental plates, grinds the mixture in its pharyngeal mill and expels the indigestible carbonate: a single parrotfish can produce close to a hundred kilos of sand a year.
• By eating sponges it indirectly protects the corals, which would otherwise be smothered by fast-growing sponge species.
• It is a sequential hermaphrodite: it starts out as a primary-phase female, and some individuals change into terminal-phase males, with a completely different colouration.
• It lives in small, stable groups of three or four females and one dominant supermale.
• It spends up to 90% of the day feeding, and it is not a strong swimmer: it propels itself by rowing with its pectoral fins.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat and environment

Coral reefs of the Caribbean and the tropical western Atlantic

Sources consulted: https://es.wikipedia.org/wiki/Scarus_vetula