How Much Oxygen Do Flies Need?
WouterUnlike us, insects don’t have lungs; they breathe by breathing through tiny openings in their exoskeletons called spiracles. Air passes through these air tubes and then diffuses into the body’s tissues. Since insects don’t have lungs, the amount of oxygen they need to sustain metabolism is much lower than human beings.
The temperature of the environment may also affect the fly’s response to oxygen. Flies exposed to high levels of oxygen at 37degC performed better than those exposed to low oxygen. In contrast, flies exposed to low oxygen in hot environments performed poorly. These results suggest that the temperature of the body influences the ability of flies to fly in various conditions.
However, the exact mechanisms by which flies obtain their oxygen are not fully understood. While humans need one gram of oxygen per liter of blood, flying insects need up to six times that amount. They produce up to 600 times the amount of metabolic flux of humans. Therefore, it is difficult to estimate the amount of oxygen that flies need.
In the tethered flight of Drosophila, the proboscis sticks out. The protrusion is correlated with CO2 cyclicity, and it may act as a mechanism for balancing local oxygen supply. This mechanism is thought to benefit the fly’s brain, which uses extra oxygen during flight.
