aiter, there's a DNA test in my soup!"

You won't hear such an exclamation any time soon, but researchers have come up with a way to distinguish among several species of shark by testing their fins. The development could be important in helping to crack down on the exploitation of certain species for shark fin soup.

Shark fins are prized for the soup, particularly in Asia, and as the rest of the shark is often of little value, the tendency is to slice the fin off and throw the shark back, leaving it to die. The fins are then dried for sale, and it is very difficult to identify the type of shark by examining a dried fin. So conservationists have a hard time telling which species are being used.

The new DNA test was developed by a team led by scientists from Nova Southeastern University in Fort Lauderdale and Imperial College in London and the Wildlife Conservation Society. As described in the journal Conservation Biology, the test can be used with shark fins, fresh or dried, or other body parts. It can distinguish among six species common to the North Atlantic, but the researchers hope eventually to be able to test for as many as 35 shark species that are caught commercially.