The crustacean’s ability to survive at low temperatures will determine whether or not it will be able to establish itself in Antarctica, where it could become a problem for local communities.

In 2010, American scientists found a female specimen with eggs on the Antarctic Peninsula.

The crab, Halicarcinus planatus, is a small crustacean dwelling off the southern tip of South America, including the regions of Aysén and Magallanes and the sub-Antarctic islands of the Southern Ocean (Malvinas, Marion, Crozet, Kerguelen, and Macquarie). This species is able to reduce the magnesium concentrations in its body, allowing it to live and develop in areas with extreme temperatures.

The discovery of a Halicarcinus planatus specimen in the Antarctic led Zambra López, a PhD student at the Universidad de Chile, to join with the Research Center Dynamics of High Latitudes Marine Ecosystems (IDEAL) of the Universidad Austral de Chile in order to study and determine the crab’s thermal tolerance for Antarctic temperatures.

“Eight years ago, an American researcher found a female of this species with eggs on Deception Island, in the Antarctic Peninsula (south of the South Shetland Islands),” says Lopez.

The presence of this crab in Antarctica could be random. However, at some point in time, the crab could also become present in high densities, in which case, Halicarcinus planatus would become an invasive species.

“The factors that are happening today – such as climate change, which favors increasing temperatures in Antarctic waters, and increased traffic by ships carrying ballast water – could help this crab enter and settle in shallow Antarctica waters,” explained López, whose doctoral thesis is sponsored by Dr. Elie Poulin, an academic at the Universidad de Chile and co-sponsored by Dr. Luis Vargas-Chacoff, IDEAL Center researcher and academic from the Universidad Austral de Chile, and Dr. Karin Gérard, associate researcher at the Universidad de Magallanes (UMAG).

Karin Gérad and Zambra López extracting Halicarcinus planatus specimens.

Gérard also notes: “Now we are going to see if the crustaceans that are in the sub-Antarctic zone are able to reach the Antarctic; we have to evaluate their dispersal capacity and if they can survive the climatic conditions there.”

The genetic study relies on samples collected by diving in the Magallanes and Aysén regions and the Falkland (Malvinas) and Kerguelen islands, as well as specimens from New Zealand. The specimens will be exposed to different Antarctic temperatures (from 5 to -1° C degrees) in order to determine their survival capacity.

The results of the Halicarcinus planatus physiology experiments will be presented between the second half of 2018 and the first semester of 2019, allowing the research team to further their knowledge of this species that has been poorly studied at international level, has survived great climatic changes, and could be a key component of the Antarctic continent’s ecosystem.

“This study will indicate not only the ability of this crab to survive but also the physiological changes that occur at low temperatures,” concluded Dr. Vargas-Chacoff.