Octopus researchers have confirmed the multiple paternity of the octopus. (Photo: USC/Stock File)
Multiple paternity of octopus uncovered
(SPAIN, 3/16/2010)
A team of biologists at the Department of Biochemistry and Molecular Biology of the University of Santiago de Compostela (USC) discovered that the octopus has multiple paternity, and that its offspring can stem from three or four different parents.
The findings were made within the framework of a project centred on octopus fattening in captivity, financed by the Xunta de Galicia and the Ministry of Environment and Rural and Marine Affairs (MARM). Autonomous sea communities also took part.
During the investigation, scientists discovered that the males have a modified third right-arm, which they employ to transfer sperm packages to females, and which can remain viable within the same for up to 10 months.
As much the females as the males have multiple mating partners, therefore, a type of competition can thrive among the masculine octopus to eliminate the sperm of the previous male from the female and leave behind its own genetic footprint.
Upon observing this reproductive behaviour, the biologists studied and analysed the genotypes of the females and their egg-layings in depth.
"The results obtained throw the existing theory out the window for now, and confirm the multiple paternity of the octopus, that is, that although the last male pulls out the espermatophores [sperm packages] of the previous one, there is always some sperm left in the body of the female, the result of prior mating,” the experts noted in an official statement.
According to Manuel Rey Mendez, coordinator of the project and a USC professor, “according to the data compiled, at least two males were successful in the fertilisation of eggs coming from the same egg-laying.”
The third arm of the octopus was modified evolutionarily for this operation of sperm elimination of the previous male.
"This first evidence of multiple paternity in the octopus is vitally important and must be taken into account in the genetic studies of populations and conservation of the species, as well as in the design and management of the aquaculture of the common octopus,” Rey Mendez added.
"At present the full cultivation of the octopus on an industrial scale is not possible, although it has indeed been achieved in the experimental field, ”the biologists noted. "Only experiences of fattening in rafts exist, after catching juveniles of legal size that were fed in controlled cages,” they specified.
With this system “impressive fattening is obtained, such that the octopuses reach three kilos in three months”
By Analia Murias
editorial@seafood.media
www.seafood.media
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