Prolonged diving and recovery in the freshwater turtle, Pseudemys scripta—II magnitude of depression of O 2 requirements and the relation to body O 2 stores

Abstract

1. 1. The magnitude of post-diving repayment of apparent O 2 deficit that occurred during a 6-hr diving period was determined in the freshwater turtle ( Pseudemys scripta elegans) and analyzed in terms of body O 2 stores and O 2 utilization. 2. 2. Oxygen stores were exhausted in 1 hr, indicating that there was a 39% reduction in O 2 reduction in O 2 utilization during the first hour of diving. 3. 3. Post-diving repayment of total apparent O 2 deficit averaged 33.8± 31% and repayment of metabolic apparent O 2 deficit averaged 22%. 4. 4. These results support the hypothesis that energy requirements are depressed during prolonged diving and that reduction of energy requirements is a major mechanism for survival during this process.