Thursday , May 26 2022

Unknown freshwater residents revealing Antarctica and Patagonia secrets – mundacuicola


A group of crustaceans live virtually every aquatic ecosystem and highlighted the researchers of Chile (Mundo Acuícola).

The copepods, or are also called "super-crustaceans" for their high resistance and their flexibility to extreme environments. Today, they provide clues for the rare white continental terrestrial and freshwater fauna and its contact with South America.

Its small dimensions are not a barrier to distribution across the planet. They are part of sopanctone in marine and freshwater environments, in addition to fulfilling a fundamental role in the food chain and identifying environmental changes. There is a group of spouses living in almost all aquatic ecosystems and has highlighted the researchers of Chile.

For this reason, the Ministry of Environment published records of 14 species of copies of the genus Boeckella living in Chileagonia and Argentina, in the Antarctica and Antarctic Macedonia. The work was prepared by scientists from the Institute of Ecology and Biodiversity (IEB), University of Chile, University of Magallanes, Costa Humboldt and the British Antarctic Survey (United Kingdom), in order to facilitate research and democratize access to data on Freshwater Biodiversity which was examined a bit.

"Antarctic terrestrial or freshwater fauna is very scarce and less compared to the biodiversity of the sea, since there are no mammals, amphibians or reptiles and there are only one species of birds there. In addition, many are believe that the whole continent has frozen, but with the largest variety of liquid water systems, such as roads, lakes, among others, where copepods live, "said Claudia Maturana, scientist at the Institute of Ecology and Biodiversity, who receives support from CONICYT and the Chile Antarctic Foundation for its investigation.

Although Magellanic and Antarctic lakes are usually oligotrophic, that is, they do not have some nutrients, they are also different from each other.

While in Patagonia there is more wealth of Boeckella species, but only the white continent can see Boeckella poppei. This precisely species was the interest of scientists that the only invertebrates present were Antarctica continental lakes, Antarctic Peninsula and sub-Antarctic islands.

"Although there are other freshwater copepps on the white continent, Boeckella poppei This is the only creature that has such a great presence in this territory, "explained Maturana, who explained part of this work at the Museum of Natural History of London a few days ago.

The main characteristics of these animals include their high resistance and flexibility. For an idea, this artropod has a very intense red color that is protected from UV radiation, and lives in extensive and deep lakes that connect to marine waters, or in smaller ecosystems and lower than fed on melting the ice, presenting at a temperature below 5 ° C, and even below 0 ° C.

"This animal can remain in the condition of eggs for many years, as if it were hibernating, to survive extreme conditions. In winter, for example, the Antarctic lakes are frozen, then I you join you can go to depth or lower your level of metabolism. "

The IEB researcher added: "In 2012, a team of Chinese scientists analyzed sediments of lagoon near its Antarctic base and detecting viable eggs from Boeckella poppei, who was 100 years old and could come in at any time. "

Did it take by the whale industry?

At present, one of the big questions is how Boeckella poppei He became one of the few representatives of Antarctica's terrestrial and freshwater fauna.

"There is no certainty about what happened when the continent passed through the last great glaciation over 20 thousand years ago. Although there is some comment that everything has turned off, others think that some species survived with the help of shelters, "says Maturana.

Given its extensive distribution in Antarctica, the Boeckella poppei It forms a model to test the two previous hypotheses.

The big question is whether this copepod inhabited the southernmost continent of the Earth from the Patagonia or sub-Antarctic islands, or could survive by taking refugees in remote areas during glacial periods and climatic changes over thousands of years.

Although there is a link between populations of Boeckella poppei From Antarctica to Phagagonia, this would not be very late as it would have been more than 20,000 years. In any case, he has not yet explained how these organisms move. Some of the possible explanations suggest that sea birds traveling between the two continents may become vectors when moving these cushions.

Another possible mechanism would come to the day of the whale industry in the nineteenth century. The crew of the ships was extracting fresh water from Antarctic lagoons, which was stored in use bargains and other uses. Therefore, when carrying or emptying the containers with a liquid, the cetacean hunters were able to move the copepod into places where they had not been in the foreground.

However, none of these theories have to prove. "Antarctic copper populations are still very surprising and a little interrupted. We have not found more human impact," the scientist states.

Despite its prominent "super-crustacean" features, there is no clear idea of ​​the differentiation mechanisms and adapting to the different ecosystems in which it lives. An example of this is that some individuals have had a reduction in their body size and weddings, in response to lower available resources in the Antarctic continent.

"Although the role of these animals has been studied as climate change letters or as water quality indicators, research on the evolutional patterns of freshwater fauna was not investigated, which is why it is important to produce and provide information from Chile to learn more about freshwater biodiversity in high lats ", Maturana.



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