Temperature directly proportional to lifespan in cold-blooded animals

Washington, July 28 (ANI): Warmer temperatures make cold-blooded organisms like fish, amphibians, crustaceans, and lizards live longer at higher latitudes than at lower latitudes, according to a study.

Led by Stephan Munch and Santiago Salinas, from Stony Brook University, the study focussed on a diverse range of species whose body temperatures vary with the temperature of their surroundings.

And they found that ambient temperature is the dominant factor controlling geographic variation of lifespan within species.

"We were intrigued by the fact that that pearl mussels in Spain have a maximum lifespan of 29 years, while in Russia, individuals of the same species live nearly 200 years," said Dr. Munch.

He added: "We wondered how a relatively small difference in latitude (Spain 43:N and Russia 66:N) could have such a drastic impact on lifespan. While one might expect that local adaptations or geographic variations in predator and food abundance would account for this disparity, we wanted to see whether the geographical variation in lifespan that we see in all sorts of species has a common physiological basis in temperature."

For the study, the researchers looked at lifespan data from laboratory and field observations for over 90 species from terrestrial, freshwater, and marine environments.

They studied organisms with different average longevities-from the copepod Arcartia tonsa, which has an average lifespan of 11.6 days, to the pearl mussel Margaritifera margaritifera, which has an average lifespan of 74 years.

They found that across this wide range of species, temperature was consistently exponentially related to lifespan.

"It is interesting to consider how cold-blooded species are likely to react in the face of global warming. Because of the exponential relationship between temperature and lifespan, small changes in temperature could result in relatively large changes in lifespan. We could see changes to ecosystem structure and stability if cold-blooded species change their life histories to accommodate warmer temperatures but warm-blooded species do not," said Salinas.

The study has been published in the online edition of the journal Proceedings of the National Academy of Sciences (PNAS). (ANI)