The effects of temperature on specific dynamic action and ammonia excretion in pikeperch (Sander lucioperca)

From oxygen consumption rate and TAN excretion measurements, we established nitrogen quotients at 13 °C, 19 °C, and 25 °C. Nitrogen quotients were used to calculate instantaneous protein catabolism at the different temperatures. We found, that protein usage (17%-29%) was unaffected by temperature during fasting, but increased significantly in the course of digestion, where it became the main energy source at all experimental temperatures. Energy spent on digestion and the relationship between excreted and ingested nitrogen were unchanged with temperature. However, SDA was of shorter duration at 19 °C than at 13 °C, and a smaller fraction of metabolic scope was utilized for digestion at 19 °C, compared to at 25 °C. We therefore conclude that 19 °C is a more favorable metabolic temperature for this species.