As described on the previous page, the Ampullae of Lorenzini are small, gel-filled bulbs found in the head of sharks. While scientists know how each ampulla works in detecting an electrical charge, not much is know about the exact function of the gel.
The gel of most marine species contains about 97% water, large sulfated glycoprotein molecules; sodium, calcium, and chloride ions that match the concentrations of the ions found in seawater, and potassium (Brown et al, 2002). The glycoproteins help support the gel structure, and the sulfates ensure that the glycoproteins remain charged, hydrophilic, and nonfolding.
Along with the physical properties of the gel, scientists have been able to determine many of the electrical properties of the gel as well. It has been found that, while the gel has similar properties to seawater, the gel was found to have much lower voltage noise than seawater (Brown et al, 2002). This means that the gel helps to detect and transmit a more consistent electrical charge. Scientists also found that temperature had a strong effect on gel resistivity, which could impact sharks that live in deeper and colder waters.
While much is known about the physical and electrical properties of the gel, not much is known about the specific function of the gel. Because of the high glycoprotein content, the gel may simply support the structure of the ampulla. The gel could also help protect the shark from infection through the open ampulla. Finally, because of the electrical properties of the gel, it could aid in transmitting the electrical charge down the canal of the amuplla or help to amplify the charge. Much more research will need to be conducted to determine the exact function of the gel.
|STRUCTURE OF THE AMPULLAE|
|THE FUNCTION OF THE GEL IN THE AMPULLAE|
|THE COMPASS SENSE|
|NEURO-ECOLOGY AND PERIPHERAL MORPHOLOGY|
|ELECTRICAL SHARK DETERRENTS|