Table 2 Cardiovascular performance parameters of C. pagurus under different water PO₂ acquired with infra-red photoplethysmography

Animal

1

2

3

4

1

2

3

4

P_wO₂ during IR-PPG (%air saturation)

97.93 ± 0.36

97.93 ± 0.36

99.32 ± 0.22

97.93 ± 0.36

16.58 ± 1.64*

16.58 ± 1.64*

15.63 ± 0.12*

16.58 ± 1.64*

99.32 ± 0.22

15.63 ± 0.12*

HR (bpm)

31.15 ± 15.51

72.31 ± 12.12

40.99 ± 12.75

67.74 ± 1.49

47.80 ± 4.02*

41.55 ± 3.52*

37.41 ± 7.52*

33.76 ± 5.30*

25.17 ± 13.30

35.03 ± 13.89*

SVP from IR-PPG (log₂ relative to normoxia)

−0.14 ± 0.57

− 0.05 ± 0.38

−0.01 ± 0.19

−0.01 ± 0.20

−0.69 ± 0.21*

0.92 ± 0.26*

0.48 ± 0.03*

−0.57 ± 0.73*

−0.12 ± 0.67

−0.05 ± 0.34