- How do clown fish survive in anemones
that would instantly kill and eat any other fish?
How do they avoid becoming a meal
for an anemone that gets most of its food by eating fish?
Hi guys and girls, I'm ReefMan
and we'll be answering these questions and more
in this video.
It's long been thought
that most of the protection afforded to clown fish
involves their skin's mucus coating.
In studies where scientists removed the slime coat
from the skin of clown fish,
their anemone actually ate the fish,
so it's clear that the slime coat is involved
in the protection.
But what else is going on?
And are clown fish just born
with this innate ability to not be stung?
Well, it turns out no.
Clown fish have to adjust to each and every anemone
that they host in on their own.
And it of course is an easy thing to do
when you're a Percula clown fish
that spends nearly its entire life
in just a single Heteractis magnifica anemone.
In fact, in a paper which was just published as a preprint,
and that means that it's been peer reviewed,
so that might change a little bit.
But that paper found that the anemone changes
almost as much as the clown fish.
So, "Microbiomes of clown fish
"and their symbiotic host anemone
"converge before their first physical contact"
looked at the microbiomes
of both the skin of Percula clown fish
and Heteractis magnifica anemones.
Don't be thrown off by the word microbiome either.
That's really just the bacteria
that lives on the skin of these animals,
so it's not something to be afraid of.
This research team in Quebec in Canada
was actually the first
to look at both the microbiome of the fish
and the host anemone,
in a way that shows how they change
as they become accustomed to each other.
It turns out
when a clown fish gets anywhere near an anemone,
their skin bacteria makeup actually changes
within about 15 minutes.
Clown fish usually hover over and near their anemones
before diving into their tentacles,
which gives ample time for this process to happen.
And at the same time, the makeup of the bacteria
living in the mucus of the anemone
also adjusts to better match that found in the clown fish.
So, it's not just the clown fish
that's adjusting in this relationship.
Clown fish get an obvious benefit from their host anemone,
they're safe amongst the stinging tentacles,
but the anemone also gets a benefit
in the form of chemical waste to feed its zooxanthellae.
It's also thought that the visual sight of clown fish
in the tentacles
might actually trick other small fish into venturing in,
and of course, they'll quickly become food for the anemone
when they do that.
So the microbiomes of both the fish and the anemone
converge within a few minutes of being near each other.
And note that there doesn't actually need to be
any physical contact for this to happen.
The researchers tested this
by simply connecting the water systems of tanks,
where one tank contained clown fish
and the other contained anemones,
and then, they looked for changes amongst the two.
The microbiomes changed
just as much as when the fish were in the same tank
as the anemones.
This study was actually the very first to show
that the anemone microbiome also changes.
That hadn't been studied before,
and we always thought that the anemone
was kind of a static thing,
and it was the fish adjusting to it.
Interestingly, this convergence sticks around,
even after the fish are no longer in the same water
or in the anemone.
The clown fish maintained their adjusted microbiome
for some time, a couple of weeks,
while the anemones quickly forget the clown fish
and they revert back to their default microbiome
without any sort of remembered imprint from the fish.
Beyond adjusting the bacteria that live in their slime coat,
it's also thought that clown fish might use
some of the anemone's slime coat
to further disguise themselves.
It's also theorized that fish like these,
and there are other fish that live in anemones,
they might have a bit of an innate immunity
to the nematocysts of anemones.
But that study that removed the slime coat
proved that the fish do actually get eaten
if they don't have that slime coat.
I think we all had the idea that clown fish,
they do something just involving their slime coat
to protect themselves from their host anemone.
And in that regard,
it's fascinating that the anemone itself changes
to better fit the microbiome of the resident clown fish.
And it's even more amazing to me
that this happens in as little as 15 minutes
and without having to have any physical contact
between the animals.
Take a moment to subscribe if you haven't already.
I hope you enjoyed the video.
Check out the paper, it's linked down below.
You can get all the details in the description.
Keep in mind it's a preprint, but yeah.
Thanks for watching, I'll see you next time.
Bye!