Sharks have evolved to be highly amazing and perfect predators, and that means having perfect eyes, jaws, sensory organs, and skin.
Shark skin is covered with overlapping, spiny scales that are termed dermal denticles because of their structural similarity to teeth. These denticles have a plate-like base supporting the main body composed of dentine with an enameled capping and a central pulp cavity. The denticles function to protect the shark and to reduce frictional drag. The apex of the denticles points toward the tail which is why a shark feels relatively smooth when stroked from head to tail, but rough with a sandpaper texture when stroked in the opposite direction.
Unprovoked shark attacks may take different forms. A shark can bite a victim without warning, or it can “bump” the victim prior to attacking. It is thought that the bumping may be an attempt to assess the potential danger of potential prey or even be employed to injure or partially incapacitate prey. Bumps may also occur from sharks without any subsequent bite. When performed at speed, these bumps may result in serious abrasions or long, deep lacerations in the skin and underlying tissue, as was experienced by this patient.
Many shark bites and shark-inflicted wounds become infected. The ocean contains an array of atypical bacteria capable of infecting humans. The best described of these are Vibrio spp. and Aeromonas spp. These bacteria may be associated with rapidly progressive infections that can appear within hours of exposure. If a physician encounters a shark attack victim acutely, empiric antibiotic therapy should be started to cover the above-referenced organisms, as well as Streptococcal and Staphylococcal species. A broad-spectrum cephalosporin would be a reasonable choice in this instance. Tetanus prophylaxis should be given upon arrival at a medical care facility. Additional systemic antibiotic therapy was not initiated in this patient because he was not seen until one week following the attack, he had already received some parenteral antibacterial treatment, and there were no overt signs of infection at the time of presentation.
In patients who present non-acutely with abrasions and lacerations from shark bumping and have no signs of infection, conservative therapy appears to be appropriate. All apparent nonviable tissue should be removed, and saline rinses, mupirocin ointment, and compression wraps should assist in achieving optimal healing without any sequelae. To facilitate healing, the patient should be cautioned against vigorous use of the affected limb and encouraged to avoid such activities as contact sports.
5 Shark Facts That May Surprise You
1. Sharks do not have bones.
Sharks use their gills to filter oxygen from the water. They are a special type of fish known as “elasmobranchs”, which translates into fish made of cartilaginous tissues—the clear gristly stuff that your ears and nose tip are made of. This category also includes rays, sawfish, and skates.
Their cartilaginous skeletons are much lighter than true bone and their large livers are full of low-density oils, both helping them to be buoyant.
2. Most sharks have good eyesight.
Most sharks can see well in dark-lighted areas, have fantastic night vision, and can see colors. The back of sharks’ eyeballs has a reflective layer of tissue called a tapetum. This helps sharks see extremely well with little light.
3. Sharks have special electroreceptor organs.
Sharks have small black spots near the nose, eyes, and mouth. These spots are the ampullae of Lorenzini – special electroreceptor organs that allow the shark to sense electromagnetic fields and temperature shifts in the ocean.
4. Shark skin feels similar to sandpaper.
Sharkskin feels exactly like sandpaper because it is made up of tiny teeth-like structures called placoid scales, also known as dermal denticles. These scales point toward the tail and help reduce friction from the surrounding water when the shark swims.
5. Sharks can go into a trance
When you flip a shark upside down they go into a trance-like state called tonic immobility. This is the reason why you often see sawfish flipped over when our scientists are working on them in the water.
Biomimicry Shark Denticles
Great White Sharks are stealthy hunters and the secret is in their skin. Sharkskin is covered by tiny flat V-shaped scales, called dermal denticles, that are more like teeth than fish scales. These denticles decrease drag and turbulence, allowing the shark to swim faster and more quietly.
Olympian swimsuit designers have taken a page from the shark’s playbook and created a fabric that mimics the exact proportion of the shark’s denticles, hugely improving a swimmer’s speed. More about the great white shark can be found in our great white shark featured story.
Progress and Perspective of Studies on Biomimetic Shark Skin Drag
Sharkskin surfaces of fast-swimming sharks are characterized as non-smooth because of the presence of dermal denticles or riblet structures and exhibit an excellent drag-reduction effect. A review of the surface morphology, structure, and mechanical behaviors of shark skin is given.
Investigations into the microstructures of a single denticle and the mechanical behaviors of complete fresh shark skin containing both epidermal and dermal layers were reported. The results show that some nanostructured protuberances exist on the concave groove surface of a denticle. In particular, the completely fresh shark skin exhibits excellent elasticity, and its stress-strain curve is different from that of the corresponding epidermal layer.
Furthermore, the mechanisms of drag reduction by riblets and complaint walls were introduced, various methods of fabricating biomimetic riblet-structured surfaces were classified and summarized, and studies on the drag-reduction effects and applications of biomimetic riblet-structured surfaces were also reviewed. Based on these analyses and on the understanding of the drag-reduction mechanisms, the concept of a synergistic drag-reduction effect that is attributed to a non-smooth surface and an elastic matrix was proposed for the first time
Ideal Uses for Shark Skin Exotic Leathers
In fact, a single full-sized Grade III or IV shark skin could easily produce enough leather to make two or three belts. The leftover scraps from the belt cuts could be used to fill in patches on other exotic leather projects, or to make wristbands, tongues for shoes, and decorative tassels.
These are some of the amazing characteristics of the unique shark skin which are surely going to be effective for you to know.