Cuttlefish and their colourblind cousins, squid and octopus, see aspects of light – including polarized light – that are invisible to humans, giving them a covert communication channel. The Bristol study, published today in Current Biology found that cuttlefish were much more sensitive to polarization than previously thought.
“Cuttlefish were much more sensitive than we expected. It was previously thought that polarization sensitivity was limited to about 10-20 degree differences, but we found that cuttlefish could respond to differences as small as one degree.”
“Although color-blind, the cuttlefish has two of the most highly developed eyes in the animal kingdom. It can see well in low light and can also detect polarized light, enhancing its perception of contrast. While we humans reshape our lenses in order to focus on specific objects, the cuttlefish moves its lenses by reshaping its entire eye. Also, the cuttlefish’s eyes are very large in proportion to its body and may increase image magnification upon the retina, while the distinct “W”-shaped pupil helps control the intensity of light entering the eye.”
Cuttlefish have a visual superpower – they see the world in polarized light:
We’re generally most familiar with this particular concept from polarized sunglasses. The idea is that light that was otherwise scattered in all directions is reflected off a surface so that the light is oriented in one direction, creating a massive, intense glare. Polarized sunglasses are used to counter this effect and block out most of the reflected light. And, as far as we humans are concerned, that’s pretty much the end of it. Polarized light creates glare when we’re dealing with large, flat surfaces – anything from a body of water to a long stretch of highway – and we can use special sunglasses to block out the worst of this intense light. But cuttlefish, those marvelous mollusks, can do something far more remarkable. They can actually see the angle at which the light is reflected and polarized, and even the subtlest change will activate their color-changing defense mechanism.
Cuttlefish may use the polarization of light much like how we use color. This dimension of light could be essential in their underwater world. The researchers modeled how the world might look to a cuttlefish with high-resolution polarized vision by creating images that used colors to represent changes in polarization. These showed that there is a wealth of information available in the polarization dimension — if you have the right type of vision to see it.
This polarization acuity may have evolved because cuttlefish and other cephalopods don’t see color very well, if they see it at all. This lack of color vision was puzzling to scientists trying to understand how these animals could be masters of camouflage, able to blend in seamlessly with their surroundings. These findings suggest that cuttlefish may use polarized light to create their camouflage.
“POLARIZED LIGHT MIGHT HELP CUTTLEFISH CAMOUFLAGE, LIKE THIS PHARAOH CUTTLEFISH (SEPIA PHARAONIS) AT THE BIRCH AQUARIUM IN SAN DIEGO, CALIFORNIA, USA”
Octopus And Cuttlefish Through Alien Eyes:
Octopus, cuttlefish and other cephalopods are masters of camouflage, and they may be the closest thing on Earth to alien intelligence. To better understand them, a team of scientists took a one-of-a-kind camera to the South Pacific. Their goal: to see the ocean as no human has before.
For animals that can perceive polarized light in a more nuanced way than humans, it adds another dimension to vision. And for us, we only could see the world with more contrast colour when we wear polarized glasses, like sunglasses. So based on the research, I made this video to illustrate how our surrounding looks like if we have the same sight as cuttlefish.I shot some daily sceneries and exaggerated contrast, hue and colour tolerance to mimic cuttlefish’s eyesight. I also kept the sound which could help us locate the surrounding.
Arms and Tentacles:
“Unlike the octopus’s arms, which that animal often uses to move and carry objects, the cuttlefish’s eight arms are specialized for grasping prey after the cuttlefish captures it with its two elongated tentacles. When potential food sources such as fish or shrimp swim near, the cuttlefish can alter the color of its skin while waving its arms in a mesmerizing display. This lures potential prey to within reach of the cuttlefish’s tentacles, which can then shoot rapidly from a pocket at the base of the arms to grab the prey. The arms are also important for a defensive display in which the cuttlefish sucks water into its mantle cavity and spreads its arms in order to appear larger to its potential opponent.”
“The cuttlefish’s beak looks much like a parrot’s beak, but it is hard to see because it lies buried at the base of the animal’s eight arms. The cuttlefish can use its beak to help subdue prey and to defend itself against predators and rivals by biting. Like cuttlebones, beaks differ among species, and their remains enable scientists to identify which cuttlefish species have lived and died in certain areas.”
-An easy way to spot the difference is that arms have suckers along their entire length, while tentacles only have suckers at the tip. This means that octopuses have eight arms and no tentacles, while other cephalopods—such as cuttlefish and squids—have eight arms and two tentacles.
-The suckers of cuttlefish extend most of the length of their arms and along the distal portion of their tentacles. Like other cephalopods, cuttlefish have “taste-by-touch” sensitivity in their suckers, allowing them to discriminate among objects and water currents that they contact.
For the touch assignment, I am thinking of making a cuttlefish suit for solders. There are a lot of tactile spots on the suits, helmet, gloves and shoes. These spots work like cuttle fish’s touching sense, which it could changing colour and texture according to the surrounding. So I think solders could wear these suit when they are in the war to hide and confuse the enemy.
Hear — Elephant:
How do elephant hear?
“Elephants hear sounds by their ears, trunk and feet. “Elephants‘ ears, used in conjunction with the soles of their feet and their trunk, aid in the ability to hear sounds over long distances. On average, an elephant can hear another elephant’s call at 4 km (2.5 mi.) away. This under normal conditions would mean elephants can communicate and hear a message within more than fifty square kilometres range.”
Elephants can hear through their feet
While trumpeting may be heard a good distance away, elephants can also communicate in a low rumble that can travel as far as 6 miles, and what’s more, the elephant receiving the call picks it up through its feet.
Caitlin O’Connell-Rodwell, a biologist at Stanford University in Palo Alto, California, found that the vocalizations and foot stomps of elephants resonate at a frequency other elephants can detect through the ground. Enlarged ear bones as well as sensitive nerve endings in their feet and trunks allow elephants to pick up these “underground” or infrasonic messages.
How vibration makes sound?
“Sound waves are formed when a vibrating object causes the surrounding medium to vibrate. A medium is a material (solid, liquid or gas) which a wavetravels through. As sound waves move through a medium the particles vibrateforwards and backwards. A sound’s volume, how loud or soft it is, depends on the sound wave.”
These “Headphones” Convert Sound Into Vibration So The Deaf Can Experience Music
A new way to experience music.
wearabe modular set that translate music into vibration
Article website: https://www.good.is/articles/headphones-for-the-deaf
This project was inspired by the hearing of elephants. I learnt from my research that elephants are able to hear sound through not only by their ears but also by their feet because elephants could detect the resonance under the ground. We human also could feel the resonance when we put our hands on a speaker. So I decided to make a video to better illustrate the vibration. Even I took away the sound, we could still sense the sound, which means without hearing, we could still detect vibration.
Also, with more sophisticated devices, we could see more movements, check this amazing resonance experiment:
Smell — Elephants:
Elephants have a keen sense of smell, detecting water sources up to 19.2 km (12 mi.) away. Nostrils are located at the tip of the trunk and function in breathing, smelling, and drawing water in to squirt into the mouth.
How Their Noses Work:
A trunk is a complicated appendage. The tip is sensitive, working almost like fingers to help elephants eat. The flexible trunk shaft lets elephants shorten or lengthen their trunks and move them in all directions. But the unique makeup of an elephant’s trunk is what gives him the amazing ability to smell water several miles away. His three nostrils breathe in the scent particles, which them pass through seven olfactory turbinals filled with millions of receptor cells. These sensitive cells differentiate between scents instantaneously, even from far away. For more powerful scent collection close-up, an elephant will touch something with the tip of his trunk, such as the urine of another elephant, and bring that into his mouth to pass it to his Jacobson’s organ. This is a specialized organ in the top of his mouth that’s attached to his nasal cavity, and it’s used most often by male elephants trying to find a date.
Elephants’ keen sense of smell helps them find water up to 12 miles away, SeaWorld reports. They often wave their trunks in the air, gathering scent particles that give them not only the smell of water, but which direction and about how far away it is. Their trunks also smell potential dangers, helping them decide between bodies of water if they detect more than one.
African elephants have the best smell in the animal kingdom:
How African elephants’ amazing sense of smell could save lives:
I found a used paper row and put silver tape on it to mimic elephant’s trunk. I was inspired by the research that elephants are able to smell water a few miles away. So I had two experiments.
For the first one, I put a cup of soy milk and another cup of white glue side by side and put the long paper on my friend’s nose (She did not want to be at the front of the camera so I had to describe the process. >-<) cover her eyes with the blind folder and ask her to smell which one is which. She tried really hard because these two liquids do not have strong smell. But she guessed right! LOL.
For the second one, I also have soy sauce and peanut oil side by side. I covered the cup with a plastic box with holes because these two liquid have strong smells. And I asked my friend to smell them again. She got it right immediately this time!
I also tried to smell them. Since I covered these cups with a box, I could barely smell them using my own nose. However, the smell got stronger if I use my “trunk” to identify them.
Taste — Ants:
For the taste assignment, I was inspired by those “Rainbow-colored Transparent Ants”. Their abdomens are transparent, therefore you can see the the food they eat in full colour. Also, include myself, a lot of people now having different stomach illnesses so that they have to do medical examination like gastroscopy. So I am thinking of what if we could have a artificial stomaches that are transparent and doctors are able to see what we ate. They could easily see what’s in our stomaches, like is there any anabiosis or inflammation in stomach, instead of doing variable examinations. In this way, patients will not suffer from the examinations and doctors could easily diagnose the illness.