Lung ventilation during treadmill locomotion in a semi-aquatic turtle, Trachemys scripta

Area of Science:

• Comparative Physiology
• Biomechanics
• Animal Respiration

Background:

• Locomotion is hypothesized to mechanically influence breathing in turtles due to their rigid shells.
• Previous studies show varied effects: cessation of breathing in green sea turtles (Chelonia mydas) during terrestrial locomotion, and no effect in box turtles (Terrapene carolina).

Purpose of the Study:

• To investigate the relationship between locomotion and lung ventilation in the semi-aquatic red-eared slider turtle (Trachemys scripta).
• To compare respiratory responses during treadmill locomotion across different turtle species.

Main Methods:

• Measured lung ventilation in red-eared sliders during treadmill locomotion.
• Analyzed breathing patterns, including tidal volume and breath frequency.
• Assessed phase coupling between breathing and locomotion.
• Investigated potential use of buccal-pump or abdominal musculature for breathing.

Main Results:

• Sliders maintained continuous breathing during locomotion and pauses, with smaller tidal volumes during movement.
• Minute ventilation remained consistent due to increased breath frequency during locomotion.
• No consistent phase coupling between breathing and locomotion was observed.
• Evidence suggests sliders use abdominal muscles for breathing during locomotion, not a buccal-pump mechanism.

Conclusions:

• Locomotion affects lung ventilation distinctively in different turtle species.
• Trachemys scripta exhibits a unique respiratory strategy during locomotion compared to Te. carolina and C. mydas.
• The findings highlight the diverse adaptations of turtle respiratory systems to different environments and activity levels.