When you talk about color-changing animals, you know chameleons. Do you know other color-changing masters?
In fact, many animals have the ability to change color. For
example, moulting of mammals is also a kind of discoloration. Some animals can
change with the environment due to their specific hair. Reptiles are the most
familiar to everyone, such as chameleons, and some snakes can also change color.
Monochrome camouflage discoloration, variegated camouflage discoloration and
intermittent camouflage discoloration.
The masters of color change in this world, besides magicians, there are many creatures. Except for the chameleon, what else do you know?
You
certainly don't remember, there are the three soft males in the ocean! They
are, cuttlefish! Squid! octopus! These three brothers will change color.
Metropolis inkjet juice has a lot of claws, and they look alike! Are you
indistinguishable? Come take a look at the article.
1. What are the animals that can change color?
First, we should talk about how our vision is formed. If an
object reflects blue light, we see blue. If an object reflects all light, we
see white. If it absorbs all the light, it is black. Our color vision is like
this.
In fact, many animals have the ability to change color. Generally speaking, most animals can change color. For example, moulting of mammals is also a kind of discoloration.
Birds change feathers too. Some
animals can change with the environment due to their specific hair. Such as
certain wolves.
Of course, the speed of this discoloration is very slow. The fastest is to change at different times of the day, and the slowest is to change according to the seasons.
If it is a rapid discoloration in the narrow sense, it is mainly divided into reptiles, amphibians, fish, insects, and the focus of this article, marine molluscs.
Reptiles are the most familiar to everyone, such as
chameleons, and some snakes can also change color. Amphibians mainly refer to
some frogs. And some fish can change color. For example, flounder or puffer
fish can be used. Insects. They are masters of mimicry.
As for our marine mollusks, we have to say the three males of
the soft family: octopus, cuttlefish (squid), and squid. These animals are also
called cephalopods because of their tentacles on the top of their heads.
2. What color can mollusks turn into?
Everyone knows the Sanxiong Ruanshi. How will these three
animals change color? Wait for me to come one by one.
First, let's talk about octopus. Octopus can not only change
color, but also mimic. For example, the mimic octopus can simulate the
appearance of at least 15 animals. They can transform into many colors such as
red, yellow, brown, black, blue, and green.
They not only have ordinary monochromatic cells on the
surface of the skin, but also a kind of rainbow cell under the monochromatic
cells. The discoloration mechanism of this kind of cell is different from that
of a monochromatic cell. Can change more metal-like colors.
There are three main types of discoloration in cephalopods.
Monochrome camouflage discoloration, variegated camouflage discoloration and
intermittent camouflage discoloration. Monochrome is generally the same color,
mainly to adapt to a smooth background.
Like the sand on the bottom of the sea. The noise is to adapt
to a more complicated environment. Like stones. The intermittent discoloration
is mainly to break the sense of wholeness. Make your whole body look like
yourself.
3. Why do mollusks change color?
Any animal, if it has any characteristics, has only two
purposes. Either survive or reproduce. This ability to change color can not
only improve survival ability, but also increase reproduction ability.
Since it comes to discoloration, I have to talk about reptiles first. The discoloration of lizards and snakes generally serves three purposes.
Disguise, communication and thermoregulation. Pretend to understand
well, or deceive the predator in order to prey. Or to escape predators.
And lizards can also change the way they change color
according to the predator, such as snakes or birds. And communication is to
transmit information. For example, bright colors will appear when courtship is
successful. Failure will be bleak.
The discoloration of mollusks is similar to these purposes. On the one hand, the color change is to create a protective color, to protect yourself from the attack of predators.
On the other hand, if discoloration is
conducive to predation, then the mollusk will also change color to integrate
itself with the environment. And mollusks can also change color according to
the visual ability of the predator or the predator.
There are many predators of mollusks. Mainly cetaceans.
Because these mollusks can grow! There is no pressure to gain 3-5% weight every
day! No matter how much you eat, you can sink five pounds a day.
So predators who are too small will not be able to eat them. General predatory fish are not acceptable. Molluscs are on the bottom of the sea during the day and birds cannot eat them.
Moreover, there is mucus on the
body, and it is not slippery and can not eat. So there are only toothed whales
with big mouths.
For example, sperm whales are full of this cephalopod
mollusk, and sometimes they fight with the king squid. You know, the king squid
is said to grow to 80 tons.
However, many cetaceans have poor vision. Because vision may not be needed in the sea. Therefore, it is important to change color to avoid predators. And sometimes, the discoloration is a warning to predators not to touch me.
Moreover, for example, the octopus has a different color-changing
strategy during slow motion and fast motion.
When the speed is slow, the body color can blend well with
the surroundings, but when the speed is fast, it will adopt a bold change of
color, and there will be many bright and conspicuous colors, making oneself
look like an octopus.
Do dolphins eat octopus?
In fact, dolphins also eat octopus
Another purpose is communication. In other words, it is to
convey information and express emotions. After all, mollusks cannot speak. Then
the discoloration becomes
A natural language. Squid becomes white or transparent when it is scared. In the courtship battle, the stripes and plaques are changed to express information at the beginning.
When the body color becomes bright and
gorgeous, the fight also reaches its peak. Males also use body color changes
when communicating with females.
Moreover, the three soft males can change their body colors to make themselves similar to the opposite sex.
Especially males are good at
this. For example, octopus, because the semen of male octopus is limited, after
a mating, it will take a long time before it can come again. If it consumes its
semen cheek pouch, it loses its ability to mate.
Some male octopuses will imitate females to fake mating. The
male squid can also pretend to be a female and mate with a female squid's best
friend. After all, big squid can occupy multiple wives and concubines. This
ability to steal people is very important.
Because the temperature of sea water is almost constant. Then
the discoloration of mollusks should not have much to do with body temperature.
In fact, having said these, the most special has not been
said yet. Whether octopus squid or squid, they are color blind! There is only
one pigment in their eyes, while humans have three and birds have four. So they
can only see the colors of black, white and gray. The others are
indistinguishable.
But they can integrate with the environment accurately. Isn't
it strange? Some studies believe that this is because the eyes of the squid can
distinguish brightness. So mollusks change color because they can distinguish
the brightness and contrast of the surrounding environment. Instead of seeing
the color.
4. The mechanism of discoloration of mollusks
Pigment cells
There are a lot of pigment cells on the epidermis of the mantle of the three males. And there is more than one layer. These cells are controlled by the central nervous system.
If one side of the brain or eye is
injured, the color of this side will never change. And these pigment cells are
also pulled by muscle fibers. When the pigment cells are pulled to expand and
contract, the color of the pigment cells will change. This is the so-called
neuro-muscular regulation.
According to the different colors of the pigments, the
pigment cells of cephalopod mollusks are divided into black, red, yellow,
white, brown, iridescent and other types. These cells themselves are an elastic
sac. Pigment cells, muscle cells, and nerve fibers form a discoloration unit.
The pigment cells are in the center. Muscle cells are distributed radially around the pigment cells, pulling the pigment cells tightly. When the nerves command muscle tension, the pigment cells expand, the pigment particles spread in the capsule, and the color appears.
When the muscle relaxes, the pigment cells contract, the pigment particles are also concentrated, and the color disappears.
Rainbow cells are very different from other single-color
cells. Monochrome cells are on the surface. The rainbow cells are in the deep
layer. Monochromatic cells rely on the absorption and reflection of specific
wavelengths of light to produce colors.
The iris cell produces a brilliant color similar to metal due
to the interference of light reflection and the interaction of light. It also
takes more time for rainbow cells to change color. Up to 15 seconds.
Monochromatic cells can change color almost instantly. It can be seen that
rainbow cells may be more controlled by the central nervous system.
Electrical signals also change the color of iris cells.
Moreover, rainbow cells are stacked in multiples. Unlike single-color cells,
which are monolayers.
In 2011, American scientists discovered that the root cause of the color change was the release of acetylcholine.
The release of
acetylcholine results in the synthesis of some proteins on the iris cells.
These proteins affect the osmotic pressure in the cell membrane and cause its
water content to change.
As a result, the thickness of the cell membrane changes and
the reflection of light by the pigment changes. And these proteins can also
form arrays to change the reflection of light.
In addition, scientists discovered last year that the squids
are actually covered with light-sensitive cells, and the color changes in the
environment can be found without vision. Some studies have found that there are
many opsins in cephalopods, which are the same as opsins in the retina. To a
certain extent, it is not an exaggeration to say that they are covered with
eyes.
In fact, the discoloration mechanism of molluscs is still
unclear. The above are just some theories, discoveries and conjectures. It
needs to be further improved.
5. Factors affecting animal discoloration
There are still many influencing factors. Mainly include temperature, light intensity, mechanical stimulation, mood, circadian rhythm, and so on. Mechanical stimulation also affects mood.
If you are subjected to external forces, you will often feel scared and frightened. Different light can also induce different body colors.
Sometimes light directly stimulates the
reaction of pigment cells, sometimes indirectly by stimulating the eyes.
Because cephalopods often float on the sea surface at night and dive deep into
the sea during the day, their body color must change.
It has now been discovered that the noise produced by ships
can also cause squid to change color faster.
Nowadays, many scientists are inventing materials similar to the discoloration of cephalopods. For example, the use of miniature color sensors, or electric fields and other technologies. Maybe in the near future, we can buy a suit and wear it for a lifetime.
Discoloration
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