Heat production during diving in the fresh water turtle, Pseudemys scripta

✍ Scribed by Donald C. Jackson; Knut Schmidt-Nielsen

• Book ID: 102881774
• Publisher: John Wiley and Sons
• Year: 1966
• Tongue: English
• Weight: 574 KB
• Volume: 67
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040670204

✦ Synopsis

Heat production was measured calorimetrically in the turtle, Pseudemys scripta e k g a n s , ( a ) while submerged and ( b ) while partially submerged and breathing various gas mixtures. Submersion resulted in a profound reduction of heat production (80% ). This reduction was not merely a response to the dive per se, but depended on the oxygen concentration available to the turtle prior to the onset of the dive. Heat production while breathing gas mixtures with different O2 concentrations was unchanged down to 5% 0 2 . At 3% 0 2 , heat production was 50% of normal, and a t 100% Nz, it was 20% of normal. Uptake of dissolved 0 2 from water was found to be 6% of the 0 2 uptake from air by these turtles. These results sug- gest that following diving, there is a profound reduction i n metabolic rate, but not until the O2 stores are depleted. This low rate is primarily anaerobic and only a very low oxidative metabolism can be supported by 0 2 extracted from the water.