In an attempt to explain and understand how the fertilization process works when it comes to tortoises, Italian researchers found it necessary to give baby tortoises paternity tests.
The measure doesn't come as ethical issue, as we would be tempted to assume. In this case, it is totally practical.
Hermann's female tortoises haven't learned fidelity. Throughout their life, they mate numerous times with different partners. Whether or not this could prevent a successful fertilization has become a controversial scientific issue.
Dr. Sara Fratini, professor at the University of Florence, and her research team claim that, in this case, “the last one in” is “the first out”.
Due to a tubular system existing in the female's oviduct, the tortoises have the ability to store the entered sperm for three to four years.
As a consequence, Dr. Fratini believes that the last mate plays the greatest role in the fertilization of the eggs, since the sperm would come out of the tubes following a re-constructive route: the sperm located at the very entrance of the tube will be the first one to come out of it.
However, Dr. Fratini and her colleagues were unable to bring sufficient proof to make their hypothesis scientifically veracious.
They've found another piece of evidence instead.
After conducting a research consisting of giving paternity tests to offspring coming from 16 egg clutches, they demonstrated that the sperm mixes inside the storage tube in a way unrelated to the time of its entrance. This way, it was shown that the bigger the amount of a male's sperm inside the female, the greater his contribution to fertilization.
Nevertheless, the scientific debates on this subject haven't come to an end yet.
"At the present time, we cannot say which hypothesis is the real one," declares Dr. Fartini for BBC Nature.
But while scientists are studying, female tortoise keep searching for a suitable male to mate with. Since the Hermann's tortoises are not a numerous population, this is not an easy goal to achieve.