The ampullae of Lorenzini are a group of
organs on the
heads of
sharks. It is composed of tiny
holes, usually
concentrated in the
snout, which connect to
jelly-filled canals. These in turn connect to the ampullae (
singular ampulla), which are themselves connected to the
nervous system. The ampullae of Lorenzini detect the
electromagnetic impulses created by all
living things. They are of little use in long-range
hunting, in which the
olfactory dominates
1, but they are extremely useful within their
range of a few
inches. They are typically
pronounced and
vital in sharks deriving a substantial portion of their
diet from
shellfish and other
bottom-dwellers
2, because of their
efficacy in detecting buried
prey.
1: Some sharks can detect a single part of blood in one million parts of water.
2: Sharks such as these are also characterized by their broad, flat teeth, useful in crushing exoskeletons. Examples include the tiger shark and the nurse shark.