If you’ve ever bathed in the sun on a tropical
white sand beach, you were probably lying
in mounds of fish poo.
I’m Anna Rothschild, and this is Gross Science.
Parrotfish live in tropical waters near coral
reefs around the world.
They eat the algae that clings to the coral,
scraping it off with their powerful bird-like
beaks.
They’ll often break off whole chunks of
coral, which they grind up with these teeth
they have not in their mouths, but in their
throats called “pharyngeal teeth.”
The coral passes right through them, and comes
out the other end as a fine, white sand.
The amount varies by species, but it’s estimated
that a single giant humphead parrotfish can
poop out over 11,000 lbs of sand a year!
In fact, a huge portion of the sand found
in Caribbean and Hawaiian beaches was actually
created this way.
But, that’s not the only thing that makes
these guys a little gross.
When juvenile parrotfish sleep, they swaddle
themselves in.
Scientists aren’t entirely sure why they
do this, but they think the mucus cocoon might
be a way to block the fish’s scent from
either predators or parasites that try to
feast on them while they sleep.
Finally, one more noteworthy characteristic
is that some parrotfish change their sex during
their lifetime.
This can happen in a variety of ways, but
in many species, all the babies are born female
and then some will become male once they mature.
Way to go, Parrotfish—be who you wanna be!
As you can tell, these creatures have a ton
of truly excellent qualities, including how
they taste.
In many places, parrotfish meat is considered
a delicacy.
But research is indicating that these guys
are a really important part of reef communities.
By eating algae, they help keep reefs clean
and healthy.
So, we need to be careful to protect these
sand-pooping, mucus-wrapped, weed-wackers
of the sea.
Ew.
