This model photo was taken in the Sea World, San Diego, USA
Introduction: Parrotfishes are a group of about 80- 90 identified species of fishes which are now often considered a subfamily (Scarinae) of the wrasses to which they are close relatives. Parrot fish are abundant in and around the tropical reefs of all the world’s oceans. The average life span of parrot fish is about 7 years.
Distribution and habitats: Parrot fish are mostly tropical and are found in relatively shallow tropical and subtropical waters throughout the world, displaying their largest species richness in the Indo-Pacific. They are found on tropical reefs, rocky coasts, and seagrass beds.
Description: Parrotfish are named for their powerful, parrot-like beak formed by the fused teeth which is adopted for grasping algae from corals and rocky substrates as well as for crushing and chewing chunks of living corals. Parrot fishes are often well known for their bright colors. Depending on species, the sizes of parrot fish vary with the majority of species reaching 30–50 cm in length. However, a few species reach lengths in excess of 1 m. They use their paired set of pectoral fins primarily to swim, with an occasional flick of the tail fin for a burst of speed.
Mucus: At night, a number of parrotfish species envelope themselves in a transparent cocoon made of thick coat of mucous secreted from an organ on their head. This is a means of hiding from potential predators especially the nocturnal ones which hunt by smell such as moray eels and lemon shark. This cocoon protects the sleeping parrotfish from bloodsucking parasites.
Feeding: Although parrot fish are considered to be herbivores, they eat a wide variety of reef organisms. Their beaks are specialized for scraping algae and invertebrates from coral and rock surfaces. Also, their pharyngeal teeth crush the ingested materials during feeding. While parrotfish digest the edible portions, they excrete the undigested portions as sand. On the average, it is estimated that a specimen of parrotfish excretes about 90-100 kg of sand/year.
Life cycle: Almost all parrotfish species are sequential hermaphrodites, starting as females (known as the initial phase) and then changing to males (the terminal phase). There are some exceptions in some species in which individuals develop directly to males while females in other species do not change sex. In most parrotfish species, several females are presided over by a single male who defends them from any challenge. If the dominant male dies, the group’s largest female will change gender and color and become the dominant male. Parrotfish are oviparous; they lay many tiny, buoyant eggs into the water. The eggs float freely, settling into the coral until hatching.
Utilization: In the Indo-Pacific, a commercial fishery of larger species of parrotfish does exist. Parrotfish are not consumed in some counties while considered a delicacy in other parts of the world. In Polynesia, it was once considered “royal food,” only eaten by the king. Despite their striking colors, they are not suitable for most marine aquaria due to their feeding behavior.
References: Sea World Display, Hanauma Bay, Sea World, Encyclopaedia Britannica, Sport Diver, National Geography, Wikipedia