The Chinese water dragon, Physignathus cocincinus, is an air-breathing lizard that lives near streams and other wet forest habitats in Southeast Asia. It is a capable swimmer and can hide underwater when threatened, but it does not breathe underwater or use gill-like structures to extract dissolved oxygen.
Breath-holding, not aquatic respiration
When submerged, a water dragon closes the glottis to keep water out of the lungs and holds its breath. This can help it escape a predator or remain concealed for a time. Like other lizards, it must return to the surface to breathe air.
Why water is useful
Water provides a refuge, a travel route and a way to cool down, while nearby branches and vegetation provide basking and cover. The animal’s long tail and strong limbs support climbing and swimming. Calling this an amphibious respiratory system is misleading because the lizard remains physiologically a lung-breather.
Captive health is not a home-treatment topic
Oral swelling, discharge, poor appetite or a suspected mouth infection need evaluation by a reptile veterinarian. Do not recommend home treatment for mouth rot based on a web article. Good enclosure hygiene, appropriate temperature and UVB provision are preventive husbandry issues, not substitutes for diagnosis.
The accurate fact check
Chinese water dragons are not underwater breathers. They are forest lizards with useful breath-holding and swimming abilities. That distinction matters both for natural-history accuracy and for responsible care information.
