Female lemon sharks return to their birth waters to deliver offspring — the first direct observation of such behaviour in any shark species.

Kevin Feldheim at the Field Museum in Chicago, Illinois, and his colleagues collected and analysed DNA from lemon sharks (Negaprion brevirostris; pictured) in the waters surrounding the Bimini Islands in the Bahamas every year from 1995 to 2012. At least six female sharks born there between 1993 and 1998 later returned to give birth. The females were also faithful to particular nursery areas between the islands.

Credit: BRANDON COLE/NATURE PICTURE LIBRARY

Conservation efforts should limit fishing in such areas when females return to give birth, or should look to establish marine reserves that encompass the nurseries, the researchers suggest.

Mol. Ecol. http://doi.org/p78 (2013)