Snakes like the boa constrictor are known for squeezing the life out of their prey, but how can they avoid suffocating themselves while crushing something to death? How are snakes able to have complete corpses in their feeding tubes without choking if developing a baby interferes with human lung function? According to new study, boas can move their ribs to regulate the flow of air in and out of their bodies. The findings, which were published in the Journal of Experimental Biology, go a long way toward explaining how these snakes maintain oxygen availability while cooking their food, however exactly how they do so remains a mystery.
“The neuromuscular regulation of this behavior is yet unknown,” Brown University corresponding author John Capano told IFLScience. “We do know, however, that at least boas, and probably most snakes, can regulate extremely specific portions of ribs and recruit only a few ribs out of over 200 pairs throughout their body.”
Being crushed to death takes time, and it wouldn’t be a very efficient hunting technique if the predator followed the prey, so it seemed plausible to believe the snakes had evolved a mechanism to maintain breathing rather than just holding their breath. Capano and colleagues tested this by putting a blood pressure cuff over the ribs of boa constrictors to simulate rib compression.
When the boas were squeezed, they discovered that they could utilize lower lung parts (far from the snake’s head) as bellows to suck air in when rib motion wasn’t an option. This implies that if the front half of the body is busy squeezing the air out of a rabbit, the lower lungs can take over as a backup for the ribs. According to Capano, snake lungs are lengthy, stretching across a third of the snake’s length in boas, but they can spread up to 80 percent of the snake’s body depending on the species. However, only the frontmost areas are used for gas exchange, whereas the balloon-like latter sections are mostly used for air movement.
The rib motion of boas was also found to be remarkably similar to that of monitor lizards, which was a startling discovery. While the two are relatives, Capano claims that current molecular evidence suggests monitors are more closely linked to iguanas, making this “quite exciting to uncover.” Deadly and interesting, but the authors of the research had to put in a lot of effort to get their conclusions. Capano noted, “Snakes may be difficult to deal with since they are so flexible and move in such different ways than other creatures.”
“This makes connecting them to equipment with cables extremely difficult, since they get tangled up in just about anything.” They’re also a little terrifying because they’ll attack, hiss, and constrict to defend themselves, so keep an eye on each snake’s temperature and demeanor while you’re working.” Next, they want to see if and how snake locomotion impacts respiration, as it’s presently unknown if the rib movement required in this might obstruct or even halt breathing.