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Sea turtles are not animals as faithful as they thought. They can "betray" their places of birth and spawning (not always returning to the same, as is generally believed), their partners and even their species.
Oceanologist Maira Proietti began studying sea turtles in 2004 "width =" 460 “/>
Oceanographer Maira Proietti started studying sea turtles in 2004
This is at least what two genetic studies on the populations of these reptiles from various parts of the world, including Brazil, have been carried out by two Brazilian researchers from the Federal Universities of Espírito Santo (UFES). ) and the University of Rio Grande do Sul (FURG). The geneticist Sarah Vargas, of UFES, began her studies on sea turtles in 2005, when she began her Ph.D. at the Federal University of Minas Gerais (UFMG). "I have worked with the five species present in Brazil, but mainly in leatherback turtles (Dermochelys coriacea) and deer (Eretmochelys imbricata), two endangered species," he explains. "I studied samples from Brazil and the Indo-Pacific, but I used published genetic sequences from around the world." Her most important research began in 2008, when she spent six months in the laboratory of conservationist Nancy FitzSimmons of the University of Canberra. Australia, organization and treatment of 492 DNA samples of turtle doves. "They had already been collected by other researchers working with Nancy in 13 spawning grounds in the Pacific and the Indian Ocean, located in Saudi Arabia, in the Chagos Archipelago, Australia, in the Solomon Islands, Seychelles, Iran and Malaysia "says Sarah
" These animals have delighted me and since then I am fascinated by them ", says Proietti about his research
In 2015, as a Postdoctoral Fellow in the Science Without Frontiers Program of the National Council for Scientific and Technological Development (CNPq), she returned to Australia to badyze data from Professor Simon Ho's University Laboratory. of Sydney. "With these works, we are trying to genetically characterize populations that have never been studied with this approach," says Sarah. "It is important to understand the migratory routes of turtles, which can be born on a spawning beach in an ocean, but migrate thousands of miles and feed elsewhere." Among the conclusions include: animals from the Indian Ocean could arrive in the areas of food production in Brazil, such as Fernando de Noronha and Atol das Rocas. "We also found that the degree of filopathy of female turtles is variable," he says. This word, from ancient Greek, means "love of the home" and defines the behavior of certain species of animals to always return to specific places to feed or procreate. It was almost a certainty with respect to sea turtles. The results of Sarah's research, however, reversed this dogma. They showed that there is a genetic mix of maternal lineages with distinct origins and that the separation of populations is more complex than previously thought. This means that they do not always return and all on the beach where they were born to breed. Or there would be no new nesting sites. "This may be the only explanation for colonizing other places, or they would all be badociated with a single nesting beach, and we know it's not what's going on "
multiple taxa in marine turtles in Brazil More recently, in Brazil, Sarah has studied the multiple authorship of sea turtles in the country. As males are rarely found, as they do not leave the oceans, unlike females during the spawning period, most surveys use samples of them for badyzes of the biology of the species. "Thus, one way to obtain information about men is to use the genetic information of the females and their respective pups to infer data such as the size of the male population," says Sarah. The data has not yet been published. "But the work suggests that the breeding population of Turtlehead Turtles (Caretta caretta) on the beach of Povoação, in the Linhares District, in the state of Espirito Santo, appears to be composed of: about two men for each woman, "says Sarah.
Sarah Vargas studied turtles in Australia and Brazil "The multiple paternity rate, meanwhile, was about 50%, with a contribution of up to three males for each nest." Photo: Sarah Vargas / Personal Archive / BBC News Brazil
In other words, half of the litters have more than one parent. In other words, half of the females have puppies of three different parents. Maira Carneiro Proietti, an oceanographer at the Institute of Oceanography at FURG, began studying sea turtles a year before Sarah in 2004, still in the third year of oceanology. "Júlia Reisser and I have today created a project to study people living in the Arvoredo Marine Biological Reserve in Santa Catarina," she recalls. "We are charmed by these animals and have been fascinated with them since then and we continue to search for them." Since then, Maira has studied several species from different places. "In my Ph.D., I did research on turtles along the Brazilian coast, especially in isolated sites such as the São Pedro Archipelago and São Paulo and the National Marine Park. Abrolhos, "he explains. "In my laboratory, we also study turtle-headed turtles and olive turtles (Lepidochelys olivacea) from the coast of Rio Grande do Sul.The goal is to understand their biology and ecology." One of the main research areas of Maira involves the genetic characterization of immature populations of several species, with the aim of understanding the diversity and connectivity that unites them, as well as in relation to one another. with those living in other parts of the world, to badist in the conservation of these animals "We have identified young turtles, still puppies, in the feeding areas along the Brazilian coast, following crossings between different species that breed on the coast. coast, "says Maira. "Up to now, we have observed animals resulting from hybridization between a comb turtle and a comb head, an olive comb, a green and pompous head and an olive." According to the researcher, before these revelations, hybrid turtles had been reported in the spawning grounds. She says that young hybrids appear to have characteristic distribution patterns, different from those of adults. "For example, the results of crossing cabeuda with comb-turtles were found in greater numbers in Praia do Cbadino, in the extreme south of Brazil, which is a place of food known for the first, but where is commonly occurring, "says Maira. In general, taking into account all species, not just hybrids, the work of the scientist FURG shows that the origins of sea turtles found on the country's coasts are much more diverse than we thought previously, with significant contributions from West Africa and Caribbean regions, besides Trindade Island, Brazil. Have you ever watched our new videos on the YouTube ? Subscribe to our channel! https: //www.youtube. com / watch? v = BO9Tjsgb24M
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