Table 2. Behavioral changes of differently acclimated fish (24°C, 28°C, and 32°C) in response to increased water temperature

Behavioral changes Acclimated temperature1) Exposed temperature (°C)
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
Body movement 24°C + + + + + + + + ++ ++ +++ +++ +++
28°C + + + + + ++ ++ +++ +++ +++
32°C + + ++ ++ +++ +++ +++
Opercular activity 24°C + + + + + + + + ++ ++ +++ +++ +++
28°C + + + + + ++ ++ ++ +++ +++
32°C + + + + ++ +++ +++
Slime secretion 24°C + + + + + + + + + + ++ ++ +++
28°C + + + + + + + ++ ++ +++
32°C + + + + ++ +++ +++
Gasping 24°C ++ +++ +++
28°C ++ +++ +++
32°C ++ +++ +++
Revolving along the axis 24°C ++ +++
28°C ++ +++
32°C ++ +++
Loss of equilibrium (LOE)2) 24°C ++ +++
28°C ++ +++
32°C ++ +++
Temperature of each experimental group was increased from their respective acclimated temperature.
LOE was the end point for CTmax test.
−, none; +, normal; ++, high; +++, severe; CTmax, critical thermal maxima.