(MWN / 16-03-10)  Biologists of the University of Santiago de Compostela (USC), Pontevedra, Spain, have discovered that the octopus has multiple paternities. The babies can have three or four different fathers, since the female can store viable sperm for ten months.

In the development of this project focusing on the fattening of this species in captivity, funded by the Xunta and the Ministry of Marine Environment and in which regions with sea participate, the scientists studied the genetic of the octopus and the processes of fertilization of the females.

Males have modified their third right arm to transfer packs of sperm to females, sperm that can be viable in them up to ten months.

Both sexes have multiple have multiple partners to copulate, so some kind of competence between males exist to remove from the female the sperm of other previous  octopuses, and leave their own genetic fingerprint. When observing this reproductive behaviour, the biologists of the USC deepen their study and analyzed the genotypes of females and their spawn.

“The results -they explain in a press release- demolish the existing theory so far and confirm the multiple paternity of the octopus, it is that, although the last male pulls out the spermatophores (packs of sperm) of the previous one, there is always some sperm in the female body, as a result of the previous copulations.”

The project coordinator, Manuel Rey Méndez, insists on the fact that “according to data obtained, unless two males succeeded in the fertilization of the eggs of a same laying.”

He explains that the third arm modified evolutionarily for this action of removing the sperm of the previous one, “but it seems that it did not work perfectly well, as they can be as much as three or four different fathers.”

According to Prof. Rey Méndez, “this first evidence of multiple paternities in the octopus is extremely important and has to be taking into account in population genetics and conservational studies of the species, as well as in the design and manage of aquiculture of common octopus. Nowadays, it is not possible to get a complete culture of octopus on an industrial scale, although it has been achieved in the experimental field and there are only experiences on fattening in trays, after capturing young specimens with legal size that feed in controlled jails.”

With this system “an impressive fattening is achieved, so that octopuses can weight up to three kg in three months”. Besides, it has been observed that around the jails a lot of litters, “which implies that this activity offers the opportunity to increase the fishery at sea.”