A strange jelly found in a shark organ is shedding light on how they are able to detect very weak electrical signals. Scientists discovered this jelly has the highest proton conductivity of any biological material ever found, a discovery that could have implications for electrical engineering.
Sharks, skates and rays are all able to detect extremely faint electrical signals, which helps them detect prey through muscle contractions. They do this through an organ called the ampullae of Lorenzini.
These pore-like organs, found on the underside of skates and rays and the faces of sharks, are known to play a role in the detection of electric fields. The organ is a pore in the skin with a jelly-filled canal that leads to a set of electro-sensory cells. However, just how the electric signal goes from the pore to the cells was not known.
Researchers from the UC Santa Cruz, University of Washington, and the Benaroya Research Institute at Virginia Mason analysed the properties of the jelly to gain an insight into the function of the ampullae of Lorenzini.
They found the jelly is an extremely effective proton-conducting material – the ability to conduct protons. "This conductivity is only 40-fold lower than the current state-of-the-art proton-conducting polymer Nafion, and it is the highest reported for a biological material so far," they wrote in the journal Science Advances.
Corresponding author Marco Rolandi, from UC Santa Cruz, said: "The observation of high proton conductivity in the jelly is very exciting. We hope that our findings may contribute to future studies of the electrosensing function of the ampullae of Lorenzini and of the organ overall, which is itself rather exceptional."
Researchers still do not know how proton conductivity helps sharks, skates and rays to detect electric fields, but they believe it could be to do with the compound keratan sulfate, previously identified in the ampullae of Lorenzini.