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West Bali, about 10 meters deep. Body is roughly 10 cm across. Does not move.
The secret to stickiness of mussels underwater
Mussels survive by sticking to rocks in the fierce waves or tides underwater. Materials mimicking this underwater adhesion are widely used for skin or bone adhesion, for modifying the surface of a scaffold, or even in drug or cell delivery systems. However, these materials have not entirely imitated the capabilities of mussels.
A joint research team from POSTECH and Kangwon National University (KNU) -- led by Professor Hyung Joon Cha and Ph.D. candidate Mincheol Shin of the Department of Chemical Engineering at POSTECH with Professor Young Mee Jeong and Dr. Yeonju Park of the Department of Chemistry at KNU -- has analyzed Dopa and lysine, which are the amino acids that make up the surface adhesive proteins secreted by mussels, and verified that their roles are related to their location. The team has taken a step closer to revealing the secret of underwater adhesion by uncovering that these amino acids can contribute to surface adhesion and cohesion differently depending on their specific location.
The characteristic of mussel adhesive proteins that have been mimicked so far is that they contain a large number of a unique amino acid called Dopa. Dopa is a modified amino acid with one more hydroxyl group attached to tyrosine, and research on underwater adhesion started with the fact that Dopa makes up a large component of the adhesive protein.
However, the research team questioned the fact that this excellent underwater adhesion of mussels is enabled by only one molecule and focused on observing the number and location of lysine, which is an amino acid as frequently occurring as Dopa.
As a result, the research team uncovered that Dopa and lysine are attached to each other with about half the probability. On the other hand, it was revealed that unlike what has been known so far, when dopa and lysine are attached together, they do not always produce positive synergy. The researchers confirmed that in the case of the cation-&pi interaction, negative synergy is rather produced.
When Dopa and lysine are together, a difference in the density of water molecules occurs at the microscopic level and the concentration of water molecules around Dopa is lowered. This lowered concentration enables a difference in the hydrogen bonding strength between the benzene ring and the hydroxyl group of Dopa, thereby lowering the structural stability of the cation-&pi complex. Using the Raman spectroscopy, the research team confirmed that the CH2 group located in the lysine chain situated close to Dopa and catechol of the adjacent Dopa form an intramolecular interaction, thereby lowering its stability.
The findings of this study make it possible to confirm how adhesive protein of mussels was designed, and it shows promise to be applicable for research on adhesive proteins of other organisms in the future.
"With this new discovery on the synergy between Dopa and lysine, which are known to always play a positive role in underwater adhesion, it will change the framework of the way adhesive materials are designed," remarked Professor Hyung Joon Cha who led the research.
This research, which was recently published in Chemistry of Materials, was conducted as a part of the study titled "Understanding the underwater adhesion mechanism of adhesive organisms: controlling the balance between surface adhesion and cohesion," which is a Mid-career Researcher Program of the Ministry of Science and ICT and the National Research Foundation of Korea.
Earth&rsquos magnetic field
The Earth has a magnetic field generated by its core.
Inside the core, radioactive decay and chemical reactions generate tremendous amounts of heat. Along with this heat comes a strong magnetic field. In addition, the iron present in the core generates its own electric current in the presence of the magnetic field. This electric current causes its own magnetic field, creating an endless cycle.
Just like any other magnet, the magnetic field has two poles&mdashthe South Pole, which points to the geographical North Pole of the Earth, and the North Pole, which points to the geographical South Pole.
Earth&rsquos magnetic field (Photo Credit : Siberian Art/Shutterstock)
For years now, scientists have been pondering how marine creatures know where to go and how to continue their journeys. For example, newly hatched turtles on land have never been to sea. Nevertheless, they know their way to the popular breeding and mating areas where they can catch up with their friends and relatives.
Studies have suggested that turtles use Earth&rsquos magnetic field to navigate.
This Underwater Creature is Called a ‘Fire Worm’ and it is Terrifyingly Beautiful
The vast expanse of water that is the ocean holds mysteries that are still unknown to the modern human. In fact, there are still creatures underneath the sparkling blue-green enigma that covers 70 percent of the Earth’s surface that can both amaze and terrify you at the same time.
One of the best examples of these creatures is the bearded fireworm. Resembling the notoriously creepy home crawlers known as the centipede, the bearded fireworm has a long and flat segmented body that will make you get goose bumps.
Bearded fireworms appear like a fluffy version of centipedes but they are much scarier in reality.
According to Marine Bio, this creepy crawler is a kind of bristleworm under the Family Amphinomidae and has a scientific name Hermodice carunculata.
It is usually 7 to 10 centimeters in length but can grow to as much as 35.6 centimeters.
For marine biologists, bearded fireworms are quite a sight to behold with their colorful flat segmented body. They are considered beautiful in the world of marine biology because—unlike their annelid relatives Classes Clitellata and Pogonophora—they have striking hues that are not only photogenic but are awe-striking in real life.
Bearded fireworms have venom-filled bristles called “chaetae” that cause burning and irritation.
Unfortunately, normal people do not appreciate their beauty and are considered downright creepy. While it may not do the creatures’ justice, your instinct to avoid these creepy crawlers is right on the money. This is because the underwater creature is armed with venom-filled bristles called the “chaetae” that look like harmless beards but can cause irritation and burning when touched.
This specie of fireworms is native in the Atlantic Ocean and the Mediterranean Sea but they can also be found in some areas in the West specifically United States to Guyana. They usually camouflage in corals, sand, and mud and hide underneath stones in rocky or seagrass areas and on some muddy bottoms.
Because of their colorful appearance, some make the mistake of putting bearded fireworms inside aquariums so it is best to share this article to your family and friends to educate them about the dangers of coming in contact with this creature.
By Rhian Waller and Tim Shank
The worlds oceans have roughly 300 times more area to support life an do the worlds continents. Because greater than 75% of the deep ocean lies beneath 1000 meters, ocean depths are relatively unexplored and until recently, inaccessible. As we investigate the submarine slopes of Galápagos volcanoes we see life that no one has photographed before. The creatures that live at these depths have adapted to a way of life in one of the world's most challenging environments.
Physophora hydrostatica. A siphonophore, these animals are made up of multiple units, each specialized for a function like swimming, feeding, or reproduction. This "modular" construction allows some siphonophores to grow very large, over 100 feet in the deep ocean. Although most siphonophores live below the surface, the Portuguese Man o'War is one that rests on the surface, suspended by a gas-filled float.
The deep-sea is defined as the part of the ocean below 200 meters depth. This environment Is considered extremely harsh with temperatures of below 5 degrees Celsius, extreme pressure (2,000 meters equals about 200 times the atmospheric pressure at sea level), and no sunlight. Deep-sea animals have had to evolve, often through unusual and unique adapations, to live, reproduce, and thrive in these unique conditions.
Until the late 19th century, many people considered the great depths of the ocean too harsh to support life. As a result, it was largely unexplored. Starting in the early 1800s European scientists began to probe the depths of the North Atlantic to see if they could find life in the deep-sea. Based on some initial sampling that suggested animals lived in the deep ocean, the H.M.S. Challenger was commissioned for an around the world expedition that lasted from 1872 to 1876. It succeeded in finding diverse animal life to 5,500 meters as well as making other important discoveries. Nearly a century later, deep-sea exploration during the Danish Galathea expedition recovered animals from the Philippines Trench, at 10,190 meters.
We know that life can exist at the greatest depths in the ocean, but how have these animals adapted to these extreme environments?
Deep-sea animals have evolved ways to get around the problems associated with living below 2000m.
Given the lack of sunlight at great ocean depths, how do deep-sea animals find each other in the dark?
The lack of sun light has led to unique visual and chemical adaptations. Many fish have the ability to produce chemical light, a phenomena called bioluminescence by oxidizing organic compounds.
Many theories on the purpose of bioluminescence have been put forward, but it is still not fully understood. Scientists think that light might help species communicate, attract a mate or prey, or deter predators. Many deep-sea organisms have developed very large rudimentary eyes to maximize their ability to see this chemical light, like some of the shrimp collected in our rock dredges.
Some animals have developed unique ways of catching their prey. The Tripod fish, Bathypterois, developed large fin rays in its tails. This lets it stand on the sandy seafloor, with outstretched pectoral fins that resemble antennae. The pectoral fins aid these deep-sea fish to feel vibrations in the water and so sense their prey as it approaches.
The immense pressure at depths below 2,000 meters can crush air spaces within humans. This is why submersibles like Alvin have a thick titanium pressure sphere where the pilot and observers sit- so they do not feel the tons of pressure as they descend into the deep ocean.
Most underwater organisms do not have any air spaces. They are made up of entirely liquid or solid material, so are not affected by pressure in these spaces. However, this poses a problem for animals that move around in the water column, how can an animal go down to 2000 meters and return to 1000 meters, or the ocean surface, without gravity making them too heavy to swim upwards?
Whales dive routinely to very deep depths. They do so by taking great gulps of air through their blow holes when they're at the surface. This air moves into the lungs, but as the whale dives deeper the pressure forces air into special sinuses filled with fatty oils. The air mixes up with these oils making an emulsion, so that it cannot be crushed.
Sharks and rays are neutrally buoyant because they have large oily livers (that float) and soft watery flesh (that sink). Some bony fishes have swim bladders. These are gas cavities that constantly have gas pumped in or out as the fish moves up and down in the water column. This means they can make their bodies heavier if they want to go down, or lighter if they want to swim up. In the deep-sea species Coryphaenoides, the Grenadier fish, there is both a large swim bladder, and a large oily liver. This makes them particularly good at going between different depths.
The lack of food can a big problem for animals living in the deep-sea. In the surface waters, marine plants called phytoplankton use the sunlight to grow by photosynthesis. This is the primary source of food for many animals that live on or near the surface. As plankton dies, it sinks and becomes food for animals that live deeper in the water column. Just 1% of this food sinks to depths of 1000 meters. This is because the number of animals that live in the surface waters is high, and so much of the food is used up before it has a chance to sink into the deep ocean.
Many organisms are scavengers. They make use of the meager resources that reach these depths, such as whale carcasses, fish excreta, and dead surface plankton blooms. Many invertebrates, like amphipods, survive on the food-fall from the surface, and, in turn, become prey for other larger species.
With every expedition, more species are being discovered. Yet many great mysteries still exist. Species once thought extinct have been found alive (the coelacanth fish is one example). Still other species have yet to be found alive like the giant squid, arch. As technology improves, it will allow us to more closely observe deep-sea animals for longer periods of time and certainly teach us even more about the great and wonderful adaptations that have evolved in the world's oceans.
Diagram on left shows how the ocean is divided into different depth categories. Diagram on the right shows how deep the different colors of light penetrate into the ocean. You can see that red light doesn’t reach down very far, this is why many deep-sea animals are red, so they are camouflaged.
Diving for cover
Well over 400 anoles species, spanning a wide diversity of colors and sizes, live throughout the tropics. Some of the most unique are the semi-aquatic species, which protect themselves from predators by diving into streams.
Over the course of the study Boccia collected, observed, and released multiple species of these lizards in Mexico, Costa Rica, and Colombia. Often these dappled anoles sleep at the end of branches, ready to wake and leap as necessary to avoid snakes. “That makes them easier to find for humans at night,” says Boccia, a National Geographic Explorer.
Boccia then observed the anoles’ rebreathing behavior when they were placed in various containers filled with water. In his experiments, he found that six species could expel and re-inhale large bubbles, also called plastrons, which remain where the lizards can breathe them by clinging to the animals’ water-repelling scales. When Boccia and colleagues measured the oxygen levels in the bubbles, the levels went down over time—an indication that the anoles were consuming the oxygen.
Scientists say it’s also possible that some lizards use their rebreathing technique to forage underwater, for example on small fish.
“No one would have predicted that anole lizards would rebreathe a layer of gas [clinging] to the outside of their skins,” says Seymour, who is also a National Geographic Explorer. But because the study scientists “followed up on the observation with careful measurements. this makes the study both bizarrely interesting and scientifically rigorous.”
Look at All These Insane Deep-Sea Creatures Biologist Just Found In White Sea
Fantastic underwater photos by Alexander Semenov, a marine biologist and a professional underwater photographer. Also he is a head of the scientific divers team at the White Sea Biological Station of Lomonosov’s Moscow State University, Russia. The station was founded in 1938 and mostly it was built by enthusiasts who came here because of the amazing atmosphere that had being developed over many years at the station. This is an unusual and unique mix of students energy, serious science and the harsh northern nature.
“I’m marine biologist, specializing in invertebrate animals. Currently, I’m the Head of the Divers’ team at Moscow State University’s White Sea Biological Station where I organize and manage all sorts of underwater work. My team and I are used to diving in unfavourable and often harsh conditions, successfully conducting complex research projects. I’m a professional underwater photographer with 10+ years of experience. My key specialization is scientific macro photography in natural environments. This approach makes it possible to observe animals that cannot be properly studied under laboratory conditions, such as soft-bodied planktonic organisms or stationary life forms living on the seafloor. My personal goal is to study underwater life through camera lenses and to boost people’s interest in marine biology. I do this by sharing all my findings through social media and in real life through public lectures, movies, exhibitions and media events.
I have the unique opportunity to observe beauty in the underwater darkness, which led me to multiple collaborations, namely with National Geographic, BBC, Nature Magazine, Science Magazine, the Smithsonian Institution and much more, with people from the scientific community all around the world.
I love what I do and I love the Sea.”
This deep-sea creature is long-armed, bristling with teeth, and the sole survivor of 180 million years of evolution
Credit: C. Harding/Museums Victoria, Author provided
Let me introduce you to Ophiojura, a bizarre deep-sea animal found in 2011 by scientists from the French Natural History Museum, while trawling the summit of a secluded seamount called Banc Durand, 500 meters below the waves and 200 kilometers east of New Caledonia in the southwest Pacific Ocean.
Ophiojura is a type of brittle star, which are distant cousins of starfish, with snake-like arms radiating from their bodies, that live on sea floors around the globe.
Being an expert in deep-sea animals, I knew at a glance that this one was special when I first saw it in 2015. The eight arms, each 10 centimeters long and armed with rows of hooks and spines. And the teeth! A microscopic scan revealed bristling rows of sharp teeth lining every jaw, which I reckon are used to snare and shred its prey.
As my colleagues and I now report in Proceedings of the Royal Society B, Ophiojura does indeed represent a totally unique and previously undescribed type of animal. It is one of a kind—the last known species of an ancient lineage, like the coelacanth or the tuatara.
We compared DNA from a range of different marine species, and concluded that Ophiojura is separated from its nearest living brittle star relatives by about 180 million years of evolution. This means their most recent common ancestor lived during the Triassic or early Jurassic period, when dinosaurs were just getting going.Bristling teeth poke out from all eight jaws, ready to pierce and shred prey. The colour in this micro-CT scan reflects the density of the skeleton. Credit: J. Black/University of Melbourne, Author provided
Since then, Ophiojura's ancestors continued to evolve, leading ultimately to the situation today, in which it is the only known survivor from an evolutionary lineage stretching back 180 million years.
Amazingly, we have found small fossil bones that look similar to our new species in Jurassic (180 million-year-old) rocks from northern France, which is further evidence of their ancient origin.
Scientists used to call animals like Ophiojura "living fossils", but this isn't quite right. Living organisms don't stay frozen in time for millions of years without changing at all. The ancestors of Ophiojura would have continued evolving, in admittedly very subtle ways, over the past 180 million years.
Perhaps a more accurate way to describe these evolutionary loners is with the term "paleo-endemics"—representatives of a formerly widespread branch of life that is now restricted to just a few small areas and maybe just a single solitary species.
For seafloor life, the center of paleo-endemism is on continental margins and seamounts in tropical waters between 200 meters and 1,000 meters deep. This is where we find the "relicts" of ancient marine life—species that have persisted in a relatively primitive form for millions of years.
Seamounts, like the one on which Ophiojura was found, are usually submerged volcanoes that were born millions of years ago. Lava oozes or belches from vents in the seafloor, continually adding layers of basalt rock to the volcano's summit like layers of icing on a cake. The volcano can eventually rise above the sea surface, forming an island volcano such as those in Hawaii, sometimes with coral reefs circling its shoreline.
But eventually the volcano dies, the rock chills, and the heavy basalt causes the seamount to sink into the relatively soft oceanic crust. Given enough time, the seamount will subside hundreds or even thousands of meters below sea level and gradually become covered again in deep-sea fauna. Its sunlit past is remembered in rock as a layer of fossilized reef animals around the summit.
While our new species is from the southwest Pacific, seamounts occur worldwide and we are just beginning to explore those in other oceans. In July and August, I will lead a 45-day voyage of exploration on Australia's oceanic research vessel, the RV Investigator, to seamounts around Christmas and Cocos (Keeling) Islands in the eastern Indian Ocean.
These seamounts are ancient—up to 100 million years old—and almost totally unexplored. We are truly excited at what we may find.Life on a seamount. Feather stars and brittle stars have evolved multiple arms to reach up into passing currents. Credit: S. Samadi/MNHN/KANADEEP2, Author provided
Seamounts are special places in the deep-sea world. Currents swirl around them, bringing nutrients from the depths or trapping plankton from above, which feeds the growth of spectacular fan corals, sea whips, and glass sponges. These in turn host numerous other deep-sea animals. But these fascinating communities are vulnerable to human activities such as deep-sea trawling and mining for precious minerals.
The Australian government recently announced a process to create new marine parks in the Christmas and Cocos (Keeling) regions. Our voyage will provide the data required to manage these parks into the future.
The New Caledonian government has also created a marine park in offshore areas around these islands, including the Durand seamount. These marine parks are beacons of progress in the global drive for better environmental stewardship of our oceans. Who knows what weird and wonderful treasures of the deep are yet to be discovered.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Scientists make powerful underwater glue inspired by barnacles and mussels
If you have ever tried to chip a mussel off a seawall or a barnacle off the bottom of a boat, you will understand that we could learn a great deal from nature about how to make powerful adhesives. Engineers at Tufts University have taken note, and today report a new type of glue inspired by those stubbornly adherent creatures in the journal Advanced Science.
Starting with the fibrous silk protein harvested from silkworms, they were able to replicate key features of barnacle and mussel glue, including protein filaments, chemical crosslinking and iron bonding. The result is a powerful non-toxic glue that sets and works as well underwater as it does in dry conditions and is stronger than most synthetic glue products now on the market.
"The composite we created works not only better underwater than most adhesives available today, it achieves that strength with much smaller quantities of material," said Fiorenzo Omenetto, Frank C. Doble Professor of Engineering at Tufts School of Engineering, director of the Tufts Silklab where the material was created, and corresponding author of the study. "And because the material is made from extracted biological sources, and the chemistries are benign -- drawn from nature and largely avoiding synthetic steps or the use of volatile solvents -- it could have advantages in manufacturing as well."
The Silklab "glue crew" focused on several key elements to replicate in aquatic adhesives. Mussels secrete long sticky filaments called byssus. These secretions form polymers, which embed into surfaces, and chemically cross-link to strengthen the bond. The protein polymers are made up of long chains of amino acids including one, dihydroxyphenylalanine (DOPA), a catechol-bearing amino acid that can cross-link with the other chains. The mussels add another special ingredient -- iron complexes -- that reinforce the cohesive strength of the byssus.
Barnacles secrete a strong cement made of proteins that form into polymers which anchor onto surfaces. The proteins in barnacle cement polymers fold their amino acid chains into beta sheets -- a zig-zag arrangement that presents flat surfaces and plenty of opportunities to form strong hydrogen bonds to the next protein in the polymer, or to the surface to which the polymer filament is attaching.
Inspired by all of these molecular bonding tricks used by nature, Omenetto's team set to work replicating them, and drawing on their expertise with the chemistry of silk fibroin protein extracted from the cocoon of silkworms. Silk fibroin shares many of the shape and bonding characteristics of the barnacle cement proteins, including the ability to assemble large beta sheet surfaces. The researchers added polydopamine -- a random polymer of dopamine which presents cross-linking catechols along its length, much like the mussels use to cross-link their bonding filaments. Finally, the adhesion strength is significantly enhanced by curing the adhesive with iron chloride, which secures bonds across the catechols, just like they do in natural mussel adhesives.
"The combination of silk fibroin, polydopamine and iron brings together the same hierarchy of bonding and cross-linking that makes these barnacle and mussel adhesives so strong," said Marco Lo Presti, post-doctoral scholar in Omenetto's lab and first author of the study. "We ended up with an adhesive that even looks like its natural counterpart under the microscope."
Getting the right blend of silk fibroin, polydopamine, and acidic conditions of curing with iron ions was critical to enabling the adhesive to set and work underwater, reaching strengths of 2.4 MPa (megapascals about 350 pounds per square inch) when resisting shear forces. That's better than most existing experimental and commercial adhesives, and only slightly lower than the strongest underwater adhesive at 2.8 MPa. Yet this adhesive has the added advantage of being non-toxic, composed of all-natural materials, and requires only 1-2 mgs per square inch to achieve that bond -- that's just a few drops.
"The combination of likely safety, conservative use of material, and superior strength suggests potential utility for many industrial and marine applications and could even be suitable for consumer-oriented such as model building and household use," said Prof. Gianluca Farinola, a collaborator on the study from the University of Bari Aldo Moro, and an adjunct Professor of Biomedical Engineering at Tufts. "The fact that we have already used silk fibroin as a biocompatible material for medical use is leading us to explore those applications as well," added Omenetto.
Underwater… lakes !
The lake floor, composed mostly of mussels
Boy I’ve gotta tell you, my jaw really dropped when I heard this one. There are actual lakes, on the bottom of oceans, especially in the Gulf of Mexico region they’ve got their own shores and all. The brine water of these lakes actually hosts unique wildlife, creating an absolutely amazing environment. The fact that these are brine water means that they have an extremely high salinity, way more than the rest of the ocean, which means of course they are heavier, which is why they stick to the bottom.
Think about the very bottom of the ocean, below the waves, below the light. What’s the first thing that comes to mind ? For me, it’s a cold dark environment filled with weird squids and fish with sharp teeth. I’m guessing your first picture is (and probably should be) something else, but it most definitely wouldn’t be an underwater lake ! I didn’t even know such a thing existed until recently. I’m telling you, you really REALLY should look at these videos
These lakes are located in brine pools, which formed during the Jurassic period. During that period, the shallow lakes from the Gulf of Mexico dried out, as a result of tectonic movements in a salt-rich area and perhaps the overall heat in the Jurassic period (it was so hot there were no polar caps). Later on, the 8 km saline layer was covered with sediments and preserved, becoming an underwater lake.
Of course such extreme amounts of salt make it almost impossible to live there, but as (almost) always, some extremophiles will adapt to the extreme conditions. Such is the case with some bacteria, shrimp or mollusks that managed to find a way to survive off of the methane, which is quite abundant in the area. The bacteria get the necessary energy from it through a process called chemosynthesis and then pass it on through symbiosis, which means they rely only on chemical energy instead of solar energy, like the other ecosystems on Earth.