Some aquatic turtles can absorb oxygen from water through specialized tissues around the cloaca, sometimes called cloacal respiration. The ability is species-specific and usually supplements breathing with lungs. It does not mean all turtles can stay underwater indefinitely or that every turtle breathes through its cloaca.
A few species have specialized tissues
Certain freshwater turtles have vascularized bursae connected to the cloaca that can exchange gases with water. In some species, this supports long submerged periods, especially during cold-season dormancy when metabolism is slow. Research on the common Nile softshell turtle described cloacal gas exchange as one part of aquatic respiration. [1]
It is not the normal breathing method for every turtle
Many turtles must surface to breathe air, and the ability differs across species. A study of western painted turtles found that cloacal pumping was not required for normal aquatic gas exchange under the tested conditions, showing why viral summaries can overgeneralize from unusual species. [2]
What the phrase gets right—and wrong
“Breathing through the butt” is a memorable shorthand for oxygen uptake through cloacal tissues. It is scientifically imprecise if it suggests ordinary lung breathing has disappeared or applies to every turtle. Species, temperature, activity, and the structure of the cloacal bursae all matter.
Underwater oxygen uptake varies by species
Cold water can slow a turtle’s metabolism and lower its oxygen demand, which helps explain long submerged periods in some species. It does not remove the need for lungs across turtles as a group.
Other aquatic animals also have to manage oxygen in different ways. Fish can suffocate when water does not supply enough dissolved oxygen, while a turtle that relies on lungs must surface or use a species-specific supplemental pathway. The biology depends on the animal and the conditions.
Sources and evidence
- Comparative Biochemistry and Physiology — Aquatic respiration in the common Nile turtle ↗
Evidence for cloacal and cutaneous contributions to aquatic respiration in a turtle species.
- Journal of Experimental Biology — Avenues of extrapulmonary oxygen uptake in western painted turtles ↗
Species-specific limits; cloaca was not required for normal aquatic gas exchange in the tested painted turtles.
Sources consulted: 15 October 2026. Written with AI assistance and checked against the linked references; not independently reviewed by a subject specialist. Sources do not endorse this article. See our editorial policy.
Revision: Initial publication; the explanation was checked against the linked institutional and research sources, with uncertainty stated where relevant.