As we have explained previously our strategy to mitigate the chytriodiomycosis in the Peñalara permanent ponds is based on retiring the overwintering salamanders’ larvae that constitute the most important reservoir of the illness during winter.
Our work was recently published in Diseases of Aquatic Organisms magazine. In this article we explain how the delay in the metamorphosis of these amphibians allows the existence of larvae in the permanent lakes during the winter, making easier the persistence and transmission of the pathogenic fungus.
The pathogens that are extremely virulent, like the Batrachochytrium dendrobatidis fungus, put at risk their own survival as they eliminate entire populations of their hosts. Nevertheless, in Peñalara the pathogenic fungus is able to persist albeit the dying of most animals every year because its transmission age of the hosts structured.
To show this fact, we studied the infection of adults and larvae salamanders in ponds and streams, temporally and permanents, of Peñalara. That way we could check how the overwintering larvae in permanent ponds keep high levels of the infection during winter and that they are the ones that transmit the pathogenic fungus to new generations of larvae released every spring. On the contrary, in the temporally ponds and lakes, the larvae that are set free can also get the infection but as the water mass gets dry in summer they tend to lose the infection. Furthermore, in adults, even though they can be infected when they come in contact with water, they also tend to lose the infection due to their terrestrial habits. This way, even though in some permanent lakes most of the overwintering larvae die every year when they complete their development, the pathogenic fungus persist in the new larvae of the year that are already infected and that they will spent the winter in the water finishing the cycle next year..
We hope that the retirement and disinfection of the overwintering salamanders’ larvae that we began last year breaks the cycle of the pathogen. If we achieve it, it will be other example more of how the investigation is key to preserve the biodiversity.
Translated by Maialen Iriso.