See boa It is quite difficult to capture and consume its prey. First, the snake attacks and clings to its prey with its teeth, then it coils its body around the poor creature and slowly takes life from it. The constriction cuts off blood flow to the heart and brain. The boa then opens its jaws and swallows its prey whole. Boa uses her muscles to move prey the length of her body to her stomach, where the unlucky zebra is digested over the next four to six days.
Boa constriction mainly consumes various rodents, lizards and medium-sized birds. They are also known to be able to devour larger prey, including monkeys, wild boars, and ocelots. Regardless of what’s on the menu, how to snake manage to breathe when they squeeze an animal to death, since that constriction also squeezes the boas’ ribs uncomfortably? Unlike mammals (including humans), thoracic spasms do not have a distinct diaphragm. They rely entirely on the movement of their ribs to breathe.
Biologists at Brown University and Dickinson College conducted a series of experiments to learn more, and they describe their results in a new sheet of paper published in Journal of Experimental Biology. They discovered that Boa contractions have the ability to selectively use different parts of the rib cage to breathe during contraction. Whenever the ribs closest to the head are obstructed, the lungs essentially act as a bellows to draw air in so the snake can still breathe.
The team used a combination of techniques for their study to collect important data on airflow, muscle activation, and rib movement in vivo. All but one of the snakes used in the experiments were born in captivity, bred from coa snakes caught in Belize. According to the authors, sole stock was purchased from a reputable reptile breeder.
Co-author John Capano of Brown University performed the X-ray experiments, using a technique known as XROMM (Movement Reconstruction X-ray) to create X-ray films of snakes. He also took a CT scan and used that data to reconstruct the movements of the ribs and vertebrae in a computer model. Capano first attached small metal markers to the two ribs of each of the three adult women’s lumbar tubes. One marker is placed about a third of the body length and the other is set halfway down.
Next, Capano placed the blood pressure cuff on the ribs at those two points, and gradually increased the pressure to immobilize the snakes — essentially simulating what would happen when they crushed their prey. According to Capano, some snakes don’t seem to mind wrapping their wrists, while others hiss. The latter response proved ideal for experiments, since the hiss required the snakes to fill their lungs with air. As a result, the hissing snakes produced the largest breaths Capano could measure.
The group used ozone (commonly used to study sleep apnea and related disorders in humans) to monitor airflow in the boa’s five constrictors, build a lightweight snake mask from a plastic bottle. The snake’s breath is passed by a PVC pipe containing a fine metal mesh to create some resistance to the airflow. The pressure difference from that fixed resistance creates the flow rate.
The authors acknowledge that these results were inconsistent, mainly because the snakes repeatedly removed their masks. (Even humans find this process uncomfortable, so one can hardly blame snakes.) However, the method did provide reliable data on pressure changes and variations. volumes when snakes inhale and exhale, and biologists have been able to visually confirm that data in x-ray videos in some cases.
