Sea snakes' strange heads may let them "breathe" underwater
Although sea snakes do breathe air like us, they're certainly able to stay underwater for long periods of time. Scientists now believe that at least part of the secret may lie in a gill-like network of blood vessels in the animals' heads.
Led by Dr. Alessandro Palci, a team at Australia's Flinders University recently utilized microCT scans to image the bodies of two blue-banded sea snakes (Hydrophis cyanocinctus). Among other things, the researchers found that a complex system of blood vessels, known as a modified cephalic vascular network (MCVN), was present just beneath the skin on the forehead and the top of the snout.
It is thought that oxygen-poor blood in these vessels is able to absorb oxygen from the surrounding water – through the skin – subsequently carrying that oxygen to the brain. A fish's gills work in much the same way.
And even though the snakes still do regularly need to surface in order to breathe air, the MCVN likely allows them to do so much less frequently than would otherwise be the case.
"Basically we found that this sea snake uses the top of its head as a gill to breathe underwater," says Palci. "While the MCVN is structurally very different from the gills of fish and amphibians, its function is nonetheless quite similar."
A paper on the research – which also involved scientists from the Vietnam Academy of Science and Technology, and the University of Adelaide – was recently published in the journal Royal Society Open Science.