Hypoxia can set the elevational limits of dragonflies
Oxygen declines by ~10% for each 1000m gained above sea level. Although the impact of low oxygen on endotherms has received considerable attention, we know far less about whether or not hypoxia can set the elevational limits of terrestrial ectotherms. Here, we addressed this question using Nearctic dragonflies. First, we experimentally tested if dragonflies are vulnerable to the low oxygen found…
Oxygen levels decrease by around 10% for every 1,000 meters a location rises above sea level. While the effects of low oxygen on endothermic animals have been extensively studied, less is understood about whether hypoxia can set the upper limits for terrestrial ectotherms, such as dragonflies.
To investigate this, researchers focused on Nearctic dragonflies found in Colorado, USA. Initially, they conducted experiments to determine if adult dragonflies are susceptible to the reduced oxygen levels present at high elevations. The findings revealed that even when dragonflies were resting, they struggled to cope with the partial pressure of oxygen (PO2) found in the areas where dragonflies are typically observed at the highest elevations in Colorado.
To further explore this topic, the researchers employed a comparative analysis to see if dragonfly species capable of inhabiting higher elevations demonstrated greater tolerance to low oxygen levels. Their analysis demonstrated that the uppermost elevation at which a dragonfly species can be found is directly linked to its ability to withstand low oxygen conditions.
These results provide some of the earliest proof that low oxygen levels can act as a significant barrier to the highest elevations reached by terrestrial ectotherms like dragonflies.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
