Updated: May 23, 2021
Image 1 shows a close-up photo of the skin of a dark shyshark (Haploblepharus pictus) taken by @raychaplin
Shark skin is made of a series of very small, hard structures called dermal denticles. Each tiny scale has the same structure as a tooth, with an outer layer of enamel, dentine and a central pulp cavity.
So essentially, sharks wear an impressive armour of teeth. Not only does this provide protection for the shark, but the placoid scales also help them move through the water more efficiently. The curved structure and streamlined arrangement of the denticles help decrease the friction of the water flowing along the shark's body, by channeling it through perfectly placed grooves.
Shark skin is very rough, resembling the texture of sand paper. All of the spines of the denticles point backwards, towards the tail. So whenever you’re petting a shark, I suggest you do so from head to tail 😉
Image 2 shows a cross-sectioned microscope image (maginfication 40x) of a ragged-tooth shark’s (Carcharias taurus) skin epidermal layer with the dermal denticles protruding & how they are imbedded in the skin sub-structure. These dermal denticles also make it difficult to do surgery on sharks as you have to use quite a bit of force to get through the skin's armoured layer.
Shark skin has also been the inspiration for designing Olympian swimsuits. Fabric has been created that mimics the exact proportions of the shark’s denticles and this has proven to drastically improve a swimmer’s speed.
This is know as biomimicry. While humans work in their various professions to solve the worlds challenges, animals and plants have had a 4 billion year head start. Like sharks, there are other species among us that have adapted and evolved to optimise themselves to overcome these problems. All the best ideas and designs to solve some of the greatest problems faced by humans can be found in resilient, enduring, dynamic nature. So best we take care of it. All of it!! 🤗🌍 🦈