Elsie Carrillo

UC Santa Cruz

“A bubble for trouble: narial air bubble rebreathing in semi-aquatic snakes as an alternate strategy to prolong time underwater”

As semi-aquatic vertebrates, garter snakes are excellent breath-hold divers that enter the water to forage on tadpoles, frogs, and fish, to refuge from predators, to facilitate shedding, and, as ectotherms, for behavioral cooling to thermoregulate. From our observations of wild and captive-bred garter snakes in the lab and field, when a sufficient breath-hold is not possible, garter snakes opt for a secondary mechanism to prolong time underwater: narial air bubbles. Narial air bubbles, or a pocket of air that forms from exhaling and inhaling air, are analogous to the natural scuba gear seen in some plants, arthropods and anoles, and has never been reported in snakes. For this novel study, we used an oxygen sensor to measure oxygen consumption and determined that garter snakes are “rebreathing” air from these reservoirs when underwater. The work has the potential to be impactful in that it not only provides insight into the mechanisms that facilitate a semi-aquatic existence, but also allow a vertebrate group that is often overlooked due to ophidiophobia, or fear of snakes, to be appreciated and ultimately, conserved.


I study the mechanisms that facilitate a semi-aquatic existence. We are investigating how rebreathing through a narial air bubble allows garter snakes to prolong their time underwater as an alternate strategy when a breath-hold is not enough.

10 + 12 =