2023-08-27 05:00:00
In an environment with extreme conditions like Antarctica, can lice inhabit the seals that live there? Florencia Soto, who was born in Plaza Huincul, Neuquén, and studied biology at the National University of Comahue, he began to investigate this question in detail and He visited the white continent several times. She recently defended her doctoral thesis and approved it with “outstanding”.
He studied three of the Antarctic seal species: crabeaters, Wedell’s, and leopard seals. Yes, seals can have lice. But Soto took care to understand what those associations are like. These are very versatile oceanic insects because they adapt to environmental conditions.
Soto’s research work is called “Ecological associations in an extreme environment: the relationship between lice and Antarctic seals.” It had been initiated at the proposal of Soledad Leonardi, who later became the thesis director, a professor at the San Juan Bosco National University of Patagonia in Puerto Madryn, who presented the subject and the possibility of doing a doctorate, with a Conicet scholarship. .
The thesis was developed in five years and during each year Soto made expeditions to Antarctica. “Each species of louse parasitizes one in particular: the crabeater seal, the Weddell seal and the leopard seal. They are genus lice Antarctophthirus lobodontis, carlinii y ogmorhiniaccording to each one”.
The scientist investigated how the lice are transmitted and whether the degree of sociability of the seals is a preponderant factor. “Crabeater seals and Weddell seals are very social and are often found on the ice floes. Being more social, lice have a better chance of being transmitted,” she said.
The only way lice are spread, whether from human head lice or seal lice, is by direct contact. “Lice walk, they don’t jump, it is a myth that it is believed that they jump from head to head or from seal to seal, and in reality the only possibility of transmission is by direct contact of the hosts and by walking,” he clarified. On the other hand, the Leopards that have solitary habits, and are usually alone on the ice, far away from the rest, may not be so infested. “So that did happen, we verified that it was related to the degree of sociability of the seals,” said Soto.
Another of the surveyed observations was that the juvenile specimens (in the three species of seals) are the ones that have the most lice and not so much in the adults. One explanation that can be put forward is that juvenile seals are less adept at swimming. “To feed the seals they have to dive and search for food. Some eat fish, others cephalopods, which are squid, octopus. On the other hand, the adults have more diving experience, they do it deeper and for a longer time to look for food. The juveniles spend more time out of the water, something that gives the louse an ideal setting to be able to transmit and develop the entire cycle,” she said.
Soto discovered that Lice transmission is affected by the degree of sociability of their hosts. “In other words, the more sociable the hosts are, in the case of the crabeater and the Weddell’s, the higher the infestation prevalence values are,” he clarified.
In contrast, the leopard seal, the loneliest, was the least prevalent. So, in the leopard seals, of the 50 specimens that were sampled over 5 years, only seven seals had lice. After having approved the doctoral thesis, Soto is already starting with another advance.
“Now my focus is on the state of health of these seals. The idea is to take morphometric measurementssuch as the total length of the seal, the weight, the axillary perimeter, calculating body mass indexes, to see what state they are in,” he stressed.
He will do a postdoc on that topic. She will collaborate and form part of networks with researchers from other countries, such as Spain, who also study the biodiversity of Antarctica.
How climate change impacts animals
The problem of climate change is caused by the warming of the planet’s average temperatures, among other factors, and may also impact seals in Antarctica.
“It is something that, in fact, is happening. The reductions – especially at the poles, both in the Antarctic and in the Arctic – of sea ice are observed due to climate change”, explained Dr. Florencia Soto.
The decrease in sea ice increases the number of ships that can circulate through the area, because new roads are opened.
In the case of seals, they are dependent on sea ice. Then they would have less ice available to carry out their rest periods, either for moulting or breeding. This increases the possibility of contracting diseases and infections, he mentioned.
1693114842
#seals #lice #survive #Antarctica
