Aging stars in one of the articles in the magazine Science. Thanks to field data collected over decades by 114 experts in amphibians and reptiles in 107 populations of 77 different species, the international team, which has the collaboration of the National Museum of Natural Sciences (MNCN-CSIC) and is led by the Pennsylvania State University (USA), has verified that these cold-blooded animals (ectotherms) show a very high variability in their rates of aging and longevity compared to those of warm-blooded birds or mammals (endotherms).
amphibians and reptiles
Research has revealed that, contrary to what was previously believed, a lower metabolic rate does not always translate into slower aging or a longer life. The results provide data to establish conservation strategies and can help us understand how aging works in humans.
Until now, data on the life expectancy of amphibians and reptiles was very limited and almost always from captive animals. With this work, based on phylogenetic methods (which analyze the relationship between species) and data taken directly from the natural environment (by capturing, marking and monitoring individuals from different populations throughout their lives), have tried to test various theories about the aging of amphibians and reptiles.
“The aging rate and lifespan of ectothermic animals vary greatly above and below known rates for similarly sized endothermic animals, suggesting that how an animal regulates its temperature is not necessarily indicative of their aging rate. In fact, this statement is only valid in the case of turtles”explains the professor at the University of Northeastern Illinois (USA), Beth Reinke.
“If we can understand what factors allow some animals to age more slowly, we can also better understand aging in humans”points out the researcher at Pennsylvania State University, David Miller.
Turtles, salamanders and crocodiles, the longest
The objective of the work was to analyze the variation in aging and longevity of ectothermic animals in nature compared to endothermic animals, and to explore previous hypotheses related to aging, including its relationship with environmental temperature, the presence or absence of protective physical traits and the reproductive effort of individuals throughout their lives.
After analyzing the data provided from populations studied for years (even decades) in their natural habitat, the researchers have detected that turtles, crocodiles and salamanders have particularly low aging rates. They have also discovered that animals with physical or chemical traits that give them protection, such as armor, spines, shells or poison (protective phenotypes), have slower aging and greater longevity.
Another curious fact is that, in each of the study groups (frogs, salamanders, lizards, crocodiles and turtles), they have observed at least one species that shows a practically zero aging rate; that is, species in which, once they have stopped reproducing, the probability of dying does not increase with age.
The collaboration of the MNCN
From the MNCN, the team led by researcher Íñigo Martínez-Solano has provided data on the gallipato, Pleurodeles waltlthe spadefoot toad, Pelobates cultripesthe natterjack toad, Epidalea calamitathe frog of San Antonio, hyla molleri,and the common frog, Pelophylax perezspecies whose populations have been followed using capture-mark-recapture techniques for more than a decade in the Sierra de Guadarrama, in Madrid.
“The work that we have been carrying out, which consists of capturing, collecting data, marking the specimens and later releasing them for long-term monitoring, has allowed us to verify that some species such as the gallipato, the spadefoot toad or the The natterjack toad can reach ages of over 10 years in the natural environment, while the San Antonio frog or the common frog live less, around 5-6 years. Consistent with their differences in longevity, these species have very different reproductive strategies, which explains their demographic dynamics.”confirms Martínez-Solano.
Font: MNCN CSIC
Reference article: https://www.mncn.csic.es/es/Comunicaci%C3%B3n/los-trabajos-de-campo-de-hundreds-of-experts-reveal-why-some-reptiles-and
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