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"We wanted to investigate whether there was any geneticinformation that could tell us what the past environment could havebeen like," Louise Allcock, of the National University ofIreland Galway's zoology department, said in a preparedstatement. And for that, she and her colleagues turned to thebenthic Turquet's octopus, which lives as deep as 1,000 meters on the seafloor in the Southern Ocean. These particular polar octopods, which grow to only about 15 centimeters in length, arefound all around the continent, but they don't like to straytoo far from home, remaining on the ocean floor most of the timeand swimming only in short bursts to escape predators. "This octopus species, with its large populations around theregion and limited movements, was an ideal species to use,"Allcock said. And unlike most octopus species, Turquet's octopus laysrelatively few, large eggs (between 22 and 60, each about 20millimeters long). So when they hatch, instead of floating up intothe water column like plankton, as most species of octopus larvaedo, these more massive little ‘uns start living on the seafloor like their parents. This lifestyle prevents them fromdispersing in great numbers with the currents. Plus, both theWeddell and Ross seas have their own circular currents (gyres) thattend to keep any organisms in the area. These factors mean thatpopulation pockets of this octopus likely do not mix with othersand thus each population would be expected to have developeddifferent genetic signatures across generations if they had beenseparated for a long period of evolutionary time. The research team used data collected by the Census of AntarcticMarine Life from more than 450 individual Turquet's octopusesfrom around the continent's edges. Through that they wereable "to examine genetic data on a scale that had not beendone before in this area of the world," Phill Watts, ofUniversity of Liverpool's Institute of Integrative Biologyand co-author of the study, said in a prepared statement. The new findings were published recently online in Molecular Ecology . And when they did look into the genetic code they found somethingsurprising. "We expected to find a marked difference betweenTurquet's octopuses living in different regions of theocean," Watts said. But they found that the genetics of thetwo populations were actually very similar, "suggesting thatat some point in their past these populations would have been incontact with each other, perhaps at a time when the oceans wereconnected and not separated by the West Antarctic Ice Sheet,"he said. The team found genetic evidence of a large population growth about1902 near South Georgia and around 1829 at Shag Rocks. And the DNAdata also suggests that These tough little critters seem to have been able to ride out even the cold glacial maximumperiods in these and other areas. The new findings shore up "with climate models indicatingrepeated periods in history when the climate was warmer, whichwould have released water from the ice and increased the sealevels, allowing dispersal of creatures between the Ross andWeddell seas," Watts said. Not only does this new genetic picture help support climatepatterns of the past, but "it also provides further evidencethat scientists should continue to raise awareness about the impact of climate change on Antarctica today ," Allcock said. So these octopuses might not be psychic, butthey might help us place bets on whether they're likelyto be reunited once again in the future near. Illustration courtesy of Ivan Phillipsen. We are high quality suppliers, our products such as Toroid Coil Winding Hook , Ceramic Coating Aluminum Pulley for oversee buyer. To know more, please visits Mechanical Wire Tensioner.
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