The boa constrictor (Boa constrictor) is a killing machine. You can constrict a rat for about 20 minutes before eating it. The lethal hug is a precise operation, in which the executor is able to measure the heartbeat of his victim to continue squeezing with all his strength until he feels the last breath. However, this technique severely restricts their own lungs, so it was a mystery how snakes manage to breathe while strangling and digesting large pieces.
Scientists suspected that boas adjust different parts of their ribcage to inhale, depending on whether they are resting, strangling an animal or digesting. But until now no one had verified it. John Capano and Elizabeth Brained of Brown University (USA) placed a blood pressure cuff around the ribs of some specimens to restrict their movements and discovered that, in effect, the snakes use different sections of the box thoracic to breathe when your ribs are constricted.
When the pressure increased to one-third of the body, the snakes breathed using their rear ribs. However, when pressure was increased toward the back of their body, the snakes breathed using their ribs higher up. The ribs near the end of his lungs only moved when the front ribs contracted.
A bellows in the lung
According to the authors, who publish their findings in the Journal of Experimental Biology, the posterior section of the lung functions as a bellows, drawing air into the lung when the ribs further forward can no longer move because they are squeezing the prey to death.
Since subduing and digesting a victim is one of the most forceful things these snakes can do, it was probably essential that they developed the ability to adjust where they breathe before adopting their new rib-hindering lifestyle, to ensure that They won't suffocate. "It would have been difficult for snakes to develop these behaviors without the ability to breathe," concludes the researcher.