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Its small dimensions are not an obstacle to its distribution around the world. They are part of zooplankton in marine and freshwater environments, in addition to playing a fundamental role in the food chain and indicating environmental changes. Copepods are a group of crustaceans that live in almost all aquatic ecosystems and have attracted the attention of Chilean researchers
. Therefore, through the Ministry of the Environment, records of 14 species of copepods have been published. of the genus Boeckella that live in Chilean and Argentine Patagonia, in the sub-Antarctic islands and in Antarctica. The work was prepared by scientists from the Institute of Ecology and Biodiversity (IEB), the University of Chile, the University of Magallanes, Costa Humboldt and the British Antarctic Survey (United Kingdom), to facilitate research and to democratize access to data on the under-explored biodiversity of freshwater.
"The terrestrial or freshwater fauna of Antarctica is very rare and reduced in relation to marine biodiversity, since there are no mammals, amphibians or reptiles and it does not There is only one species of bird, and many believe that the whole continent is frozen but have the greatest diversity of liquid water systems, such as fjords, lakes, among others, in which live copepods, "says Claudia Maturana, scientist at the Institute of Ecology and Biodiversity,
Although the Magellanic and Antarctic lakes are generally oligotrophic, that is they contain few nutrients, they also differ from each other.
Although in Patagonia, there are more nutrients. the species richness of Boeckella, only Boeckella white poppei is found on the white continent. It is precisely this latter species that has aroused the interest of scientists to be the only invertebrate present in the continental lakes of Antarctica, the Antarctic Peninsula and sub-Antarctic islands.
"On the mainland Boeckella poppei is the only crustacean on this territory," explains Maturana, who exhibited some of this work at the Natural History Museum in London a few days ago.
one of the main characteristics of these animals is their great resistance and adaptability.To get an idea, this arthropod has an intense red coloring that protects it from ultraviolet rays and inhabits deep and extensive lakes that connect to marine waters or to smaller and shallower ecosystems that feed on ice melt, it experiences temperatures below 5 ° C and even below 0 ° C.
"This animal may remain as it is Egg for many years, as it hibernated, to survive in extreme conditions. In winter, for example, the Antarctic lakes are frozen. To subsist, you can go deep or lower your metabolism. "
The IEB researcher adds:" In 2012, a team of Chinese scientists badyzed the sediments of a lagoon near its Antarctic base and spotted viable eggs of Boeckella poppei, aged 100 years and able to hatch at any time. "
Whaling?
One of the big questions is how Boeckella poppei has become one of the few representatives of terrestrial wildlife and freshwaters in Antarctica.
"It does not exist The certainty of what happened when the continent pbaded through the last Great Ice Age more than 20,000 years ago, while some point out that everything has been extinguished, d 'Others think that some species have survived through shelter,' says Maturana.
Given its wide distribution in Antarctica, Boeckella poppei is a model for testing the two previous hypotheses.
The big question is whether this copepod colonized the most southerly continent of the Earth from Patagonia or the sub-Antarctic islands, or where it managed to survive by taking refuge in isolated places during ice ages and climate change that has been going on for millennia.
Although there is a link between populations of Boeckella poppei from Antarctica and Patagonia, this one would not be very recent since it would exceed 20,000 years. In any case, the way in which these organisms move has not yet been clarified. Some of the possible explanations suggest that seabirds traveling between the two continents could become vectors as they move towards these crustaceans.
Another possible mechanism would come at the peak of the whaling industry in the 19th century. The crew of ships extracted freshwater Antarctic lagoons, which were stored in barrels for consumption and for other purposes. Therefore, when transporting or emptying containers with liquid, cetacean hunters were able to move the copepods to places where they were not previously.
However, none of these theories has been proven: "The populations of the Antarctic copepods remain very virgin and little involved. " We have not detected any impact more important human, "says the scientist
Despite its obvious attributes of" super-crustaceans ", the mechanisms of differentiation and adaptation to different ecosystems are not clearly defined, the ones it inhabits. An example is that some people have experienced a reduction in their body size and female fertility, in response to less availability of resources on the Antarctic continent.
"Although their role has been studied animals as sentinels of climate change or as indicators of water quality, research on evolving models of freshwater fauna has been little explored. That is why it is important to generate and provide information from Chile to learn about freshwater biodiversity in high latitudes ", Maturana sentence.
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