Fig 1.
Schematic representation of the experimental setup.
The oxygen concentration within the respiration chamber (RC) was continuously monitored using optical fibres connected to oxygen sensor spots. Pump 1 flushed the RC with aerated reservoir water in constant time intervals controlled by a timer. Pump 2 provided constant water circulation within the RC during the whole experimental period. Up to four RC were placed simultaneously into the reservoir tank. Pump 3 ensured water circulation in the reservoir tank to provide similar flush conditions for all RC. The reservoir tank provided space for maximum four RC in parallel. Modified after [41].
Fig 2.
Schematic representation of the time setup of one experimental run.
SMR: Standard metabolic rate (green dashed line). RMR: Routine metabolic rate (blue dashed line). The arrows indicate the time of the respiratory cycles that were used for assessing handling stress response (black; 08:00 p.m.), light stress response (yellow; 08:00 a.m.), and predation stress response (red; 01:30 p.m.). The time spans used for assessing SMR (00:00 a.m.– 08:00 a.m.) and RMR (00:00 a.m.– 01:30 p.m.) are given in dashed lines (green: SMR; blue: RMR). The experimental runs were conducted on five consecutive days to finally reach n = 13.
Table 1.
Standard and routine metabolic rates of Gobius paganellus.
Biometric data are given for each individual (A-N).
Fig 3.
Oxygen consumption (OC) rates (mg O2 h-1 g-1 WW) of the rock goby Gobius paganellus under different stressors.
Results are given in mean values ± SD. SMR: Standard metabolic rate. RMR: Routine metabolic rate. Predation: OC rate after introduction of predation treatment water. Handling: OC rate after handling. Light: OC rate after abrupt change from dark to light. Different capital letters indicate statistically significant differences between treatment groups (Kruskal-Wallis, Games-Howell, significance level: P ≤ 0.05). (n = 13; Light treatment: n = 10).