San Diego Zoo researchers contribute to project using mummy DNA to differentiate croc species

The Nile crocodile is a species that was identified by ancient Egyptians. Genetic analysis done by a group of geneticists using samples taken from species throughout the animal's range and including DNA from mummified crocodile remains indicates that more than one species is known by this name.

"This paper provides a remarkable surprise: the Nile crocodile is not a single species, as previously thought, but instead demonstrates two species - living side-by side - constitute what has been called the Nile croc." Said Marlys Houck, geneticist with San Diego Zoo Global's Institute of Conservation Research. "Even more remarkably, they are not each other's closest relatives; one is more closely related to New World crocodilians. The cryptic Crocodylus suchus is a unique entity worthy of a conservation strategy separate from the Nile crocodile populations of East and southern Africa."

The study, published in the October issue of Molecular Ecology, provides important information about a species that is not only an important historical icon but also critically endangered. Recent survey efforts indicate that Crocodylus suchus is declining or extirpated throughout much of its distribution. Conservationists feel that without proper recognition of this species, current sustainable use-based management policies for the Nile crocodile may do more harm than good.

Source: Zoological Society of San Diego