
Giant clams manipulate light to assist their symbiotic partner - lelf
https://phys.org/news/2020-07-giant-clams-symbiotic-partner.html
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giarc
Another great example is Aliivibrio fischeri [0]. Generally, squids are
subject to predators as they group together and at night. The light of the
moon creates a shadow that predators recognize as a group of squid. These
squids have a special organ that lets in these bacterium that when in
sufficient numbers, called quorum sensing, actually light up. All these
bacterium glowing at the same time reduces the shadow and protects the group
of squid. The bacterium are provided a safe space and therefore this is a
great example of symbiosis.

0
[https://en.wikipedia.org/wiki/Aliivibrio_fischeri#Symbiosis_...](https://en.wikipedia.org/wiki/Aliivibrio_fischeri#Symbiosis_with_the_Hawaiian_Bobtail_Squid)

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vikramkr
V/A fischeri (a lot of people still haven't gotten used the renaming from
vibrio) is really fascinating. Slight point of clarification- quorum sensing
happens between the bacteria where they detect the amount of other bacteria
present, not through a signal from the squid. It's a phenomena that has a lot
of importance in bacterial disease and infections as well - one of those
classic cases where a scientist that wanted to study a random cool phenomenon
("but why squid glow?") advanced a fundamental understanding with broad
implications. You can see quorum sensing in action by culturing some V
fischeri in a petri dish and observing luminescence when they read high enough
numbers. You might be able to buy an educational kit online - it's not a
dangerous bacteria (my professor let us take home our plates to culture them
out to see them glow in our dorms). Super cool stuff.

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giarc
I probably just phrased it wrong, but yes, that's what I meant. The bacterium
conduct the quorum sensing when enough of them are in the squids specialized
sac.

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bdr
Pictures don't do giant clams justice at all. Seen in person, they glow like
something from outer space--like galaxies or nebulae or some kind of sci-fi
light creature.

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sradman
Indeed they are quite "vibrant", as the article states:

> This may also explain the mantle colors of giant clams. The idea is that the
> vibrant colors of giant clams are not due to optical differences in the
> tissue, but rather differences in the distribution or abundance of symbionts
> relative to iridocytes in each individual.

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raxxorrax
That is pretty cool and awfully nice of these clams. It could indeed be
inspiration to interesting tech. We already have amazing technology for light
modulation if you take a look at a DPL beamer. This tiny chips have millions
of tiny mirrors controlled by gas. At least TI does, I don't know if others
have made progress here in the meantime. An incredible technology everyone
takes for granted.

Changing the wavelength isn't trivial, this sounds very interesting. I don't
know any techniques aside from passing it to another medium.

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scentoni
Changing the wavelength like this is called
[https://en.wikipedia.org/wiki/Fluorescence](https://en.wikipedia.org/wiki/Fluorescence)
and is the basis of fluorescent lights.

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sradman
Original paper [1]:

[1]
[https://repository.kaust.edu.sa/handle/10754/663708](https://repository.kaust.edu.sa/handle/10754/663708)

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sandwall
Wavelength shifting for cooperative effect. Very interesting and beautiful
phenomenon. Fluorescence is pretty cool, 'fluorescent symbiosis,' is certainly
new to me.

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Chris2048
So are there any plants able to do the same? An entire wavelength of light
seems to be pretty valuable energy real-estate.

