Sept. 4 (UPI) -- Scientists have found a tropical sea snake that draws oxygen through the top of its head when diving underwater.
According to the latest analysis, the blue-banded sea snake uses a complex system of blood vessels to pull oxygen from the water through the top of its head.
"For the first time, we describe this modified cephalic vascular network, MCVN, that provides this sea snake with a complementary supply of oxygen to the brain during submersion," Alessandro Palci, an evolutionary researcher at Flinders University in Australia, said in a news release. "Basically we found that this sea snake uses the top of its head as a gill to breathe underwater."
Blue-banded sea snakes are found among the coral reefs and warm coastal waters of Southeast Asia. Studying them is dangerous work, as they are highly venomous.
Of all the vertebrates that breathe air, few spend as much time in the water as the blue-banded sea snake -- few are more completely aquatic.
Researchers set out to investigate the soft-bodied structures related to nerves and blood vessels in sea snakes to better understand the anatomical differences between marine-adapted snakes and lizards. Scientists were surprised to find the systems of blood vessels located just beneath the snout and forehead of the blue-banded sea snakes.
"While the MCVN is structurally very different from the gills of fish and amphibians, its function is nonetheless quite similar, in that it provides a large surface area packed with oxygen-depleted blood vessels that can efficiently take in oxygen from the surrounding water," Palci said.
The findings, published Wednesday in the journal Royal Society Open Science, have helped expand biologists' understanding of the multitude of adaptations used by sea snakes to live a fully aquatic lifestyle.
"We have discovered this interesting feature in H. cyanocinctus by using micro-CT scans and computer modelling," said Kate Sanders, a research fellow at the University of Adelaide. "This feature probably allows these sea snakes to stay submerged for longer periods of time, which further research can test."
