Little is still known about the jelly-like substance found inside a shark's head, but new research suggests that it may have an interesting scientific impact.
Sharks, along with rays and other cartilaginous fish, have a network of jelly-filled pores ending in sensory cells known as the ampullae of Lorenzini (AoL in short) - named after the Italian physician Stefano Lorenzini who first made the discovery more than 300 years ago.
These cells give sharks an ability to sense electric signals from large distances, which is instrumental in detecting both food sources and nearby predators.
Every minute movement made in the water creates an electric field - albeit an incredibly weak one - which the ampullae can detect within a certain range.
Now a study published last week in Science Advances has found that the jelly housed in tubes connecting the sensors to the pores on the skin functions as a highly efficient proton conductor - a material that allows the electric charge to flow through the tube with ease.
"An individual ampulla consists of a pore on the skin that is open to the environment, a canal containing a jelly and leading to an alveolus with a series of electrosensing cells," the researchers write.
The conductive jelly they have discovered could explain why sharks are so good at electric sensitivity, although the researchers note that the exact mechanism is not yet clear. However, it is by far the best proton conductor in the natural world.
"This high proton conductivity of the AoL jelly is remarkable, and we hope that the observation of this conductivity may contribute to future studies of the AoL electrosensing function," they write.
In fact, the jelly's capacity as a conductor is only 40 times lower than that of the leading synthetic proton conductor humans have created.
Many of our fuel cells and batteries function with the help of a polymer called Nafion, a carefully prepared state-of-the-art proton conductor that we've been using since it's discovery in the late 1960s.
If sharks can generate such a material biologically, this new discovery could potentially give us clues for the development of even more amazing proton conductors in the lab.