Article Summary:

A new study published in the journal “Conservation Genetics” has shown that two species of black-tip whaler shark (Australian, Carcharhinus tilstoni; Common, C. limbatus) have been breeding to create a third hybrid species. This was shown to have occurred by studying the mitochondrial DNA sequences and the hybrids were found at five locations on the eastern Australian coastline, a distance of some 2000km.

The practical significance of this is that if hybrids are less healthy but are common, then fishery studies may be overestimated and the numbers of black-tip sharks may be well below that needed to support commercial exploitation.