First case of hybrids among sharks

Scientists studying sharks on the east coast of Australia have discovered a surprising and unprecedented thing. Some of the species found here have an unusual tendency to interbreed. This phenomenon challenges some of the commonly accepted theories about these animals.

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The first documented case of hybridisation involves two species: blacktip sharks and Carcharhinus tilstoni. Both shark ranges overlap, and hybridisation is further supported by the fact that the two species are closely related.

Using DNA tests and body measurements, scientists at the University of Queensland, Australia, have managed to locate as many as 57 hybrids, occurring in 5 different locations. Dr Jennifer Ovenden believes that other closely related shark and ray species around the world may behave similarly:

“Encountering a wild hybrid is an extremely rare occurrence, so finding mallards and their offspring, is unusual. This mixing of species can help the sharks adapt to environmental changes. The much smaller C. tilstoni prefer the tropical waters of the north, while the much larger blacktip sharks have taken a liking to the subtropical and temperate waters off the south-east coast of Australia.

Scientists will now study the hybrids found, in terms of the extent of the interbreeding zone and fitness.

Source: uq.edu.au
Photo: Tyler Corder