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The Peculiar Parrotfish
Of the approximately 5,000 different
species of reef fish that inhabit Caribbean
waters, perhaps one of the best
known is the Parrotfish. There are many
species of this beautifully colored fish,
Unbelievable as it may sound; one parrotfish is capable of creating one ton of sand a year!
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found not only in the Caribbean, but also
throughout the Atlantic and Pacific
oceans. Like other fish found in the sea,
parrotfish possess many curious qualities
that have baffled scientists for years.
Named for an odd-looking beak that
resembles that of a parrot, this fish plays
an important role in maintaining the
health of the reef. Parrotfish can be found
eating the algae off the surface of the
reef, and occasionally they are found
feeding directly on the coral. For years,
scientists believed parrotfish were destroying
the reef, but studies have proven
that when parrotfish are prevented from
feeding along an area of the reef, the coral
is “smothered” to death by the growth of
algal mats. The grazing activity of
parrotfish keeps this in check. In fact, it
seems that these fish evolved their strong
beak-like jaws and teeth primarily for the
purpose of grinding up pieces of coral.
Parrotfish have molar-like teeth in their
throats that chew up coral so that stomach
acid can digest the algae found in and
around the coral. This ground up coral is
released as sand, creating the sandy bottom
and white beaches found in and
around coral reef ecosystems. Unbelievable as it may sound; one parrotfish is
capable of creating one ton of sand a year!
After spending the day in a school of
other parrotfish feeding on algae, seaweed,
and coral, each fish separates at
night to search for dwellings in which to
sleep. When the parrotfish has found a
place to nest in the coral, it begins to secrete
a sticky mucous forming a transparent
cocoon around its body. This unusual
process takes up to thirty minutes
to complete and another thirty minutes is
needed to get out of the cocoon in the
morning. Scientists were puzzled by this
activity, but it is now believed that the
cocoon helps to protect the fish from
predators by masking the scent of the fish.
Another curious feature of parrotfish
is that throughout their lifecycle, these
fish change their sex. A sexually mature
female parrotfish will lay its eggs, eventually
to be fertilized by males. As the
female ages, she will transform into a
male, a change made apparent by a color
transformation, in which the light female
will turn into a dark male. The evolutionary
explanation behind this sex change
is that many of these fish die young so
Before it sleeps, a parrot fish wraps itself
up in a cocoon around its body, which
masks its scent from predators at night |
there is a need for many females to release
eggs and only a few males to fertilize
them.
Parrotfish are an excellent example
of animals that have evolved traits, peculiar
as they may be, to help the survival
of the species. As with other reef
fish, parrotfish greatly depend on the reef
for food and protection. Likewise, the reef
greatly depends on parrotfish to maintain
its health. So, the next time you are
snorkeling or diving, don’t be alarmed
by the munching sound you may hear –
it’s just a parrotfish doing its job.
For more information on Green Reef please contact us at (email: [email protected] or telephone us at 226-2833.
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Reef Brief is a weekly
column published in the 
Commons