The mystery of 5-foot monsters

Strange high distortion rates of salamanders, frogs and other amphibians have made scientists floundered in recent years. Reasonable causes can come from inbreeding, parasite or pollution that has penetrated the animals' skin.

These inexplicable distortions make five-foot salamanders, redundant frogs and other amphibians born with strange characteristics that prevent them from reproducing. A 2007 study showed that in at least some cases, amphibian deformation is associated with an increasing number of infections due to very small parasite species. thrive on nutrient-rich marshes of northern American farms.

Currently, a study of tiger salamanders has concluded that inbreeding is not the cause in this case, in addition the study also shows that human activities are the cause of the present. comprehensive deformation of amphibian species.

Researchers surveyed 2000 young and mature salamanders and found that 8% of them had deformations, mainly including lower, extra, or variable (pre-limb or limb fingers). after). According to Associate Professor Rod Williams, Purdue University's School of Environmental Resources - that ratio is similar to that of many frogs.

Research by Purdue University recently discovered deformation in 160 tiger salamanders out of a total of 2000 animals tested, like the image of the upper 5 salamanders taken in April 2004. Rod Researcher Williams of Purdue University rejected the cause of inbreeding associated with high deformation rates in many animals.(Photo: Faculty of Environmental Resources, Purdue University)

Like many other amphibians, tiger salamanders return to find you mating in a single pond for the rest of their lives . Williams and Andrew DeWoody, former PhD advisor, the lead author of the study, hypothesized that the disintegration of habitats or other factors might have increased the likelihood of salamanders in the blood. The system will return to the right place and meet the same mates again, which means that there will be more couples mating in close proximity and there may be many new distortions.

But their research has shown that the genetic background of animals has nothing to do with the rate of distortion; Deformed salamanders are no longer inbreeding like other normal individuals. DeWood claims that their density has proven to be quite diverse; In fact, the level of genetic modification is approximately twice that of terrestrial animals.

Williams said: 'This is indeed the first study to testify and reject the hypothesis that inbreeding is the cause of malformation of salamanders.' This result was published in Biology Letters. .

The high rate of malformations in amphibians is a concern of scientists because they threaten the life of important animals. And because of the alarming and growing number of frogs associated with climate warming, the desperation of amphibians gives a warning about the general condition of self-conditions. Of course.'Amphibians are the best predictors for both terrestrial and aquatic species , ' William said.
This mystery has not been answered until now.

' We took into account inbreeding as an ability, an important step, but there is still a lot of work to do,' DeWoody said.