Table 3.

Thermal effects on the enzyme activities of white muscle at different transverse body positions (see Fig. 4) in two lamnid shark species

Lactate dehydrogenase Citrate synthase
Body mass (kg)Slope* (±95% C.I.)N; r2Q10 for range 5-30°C (+, -95% C.I.)Slope* (±95% C.I.)N, r2Q10 for range 5-30°C (+, -95% C.I.)
Isurus oxyrinchus
Close to RM60.23±0.056; 0.971.69 (+0.21, -0.19)0.22±0.613; 0.951.64 (+5.1, -1.2)
Midway to RM60.24±0.076; 0.961.73 (+0.29, -0.25)0.33±0.713; 0.972.14 (+8.9, -1.7)
Under the skin60.22±0.056; 0.971.66 (+0.22, -0.19)0.28±0.013; 0.991.91 (+0.04, -0.04)
Close to RM490.28±0.056; 0.981.90 (+0.25, -0.22)0.27±0.126; 0.901.86 (+0.60, -0.46)
Midway to RM490.25±0.056; 0.981.77 (+0.22, -0.19)0.37±0.176; 0.902.35 (+1.16, -0.77)
Under the skin490.24±0.036; 0.991.77 (+0.11, -0.10)0.23±0.096; 0.921.69 (+0.40, -0.32)
Lamna ditropis
Close to RM1270.19±0.056; 0.961.55 (+0.21, -0.18)0.25±0.066; 0.971.76 (+0.27, -0.23)
Midway to RM1270.26±0.066; 0.981.82 (+0.25, -0.22)0.23±0.036; 0.991.68 (+0.16, -0.14)
Under the skin1270.21±0.036; 0.991.61 (+0.11, -0.11)0.21±0.036; 0.991.61 (+0.10, -0.10)
Close to RM1360.25±0.066; 0.971.76 (+0.26, -0.23)0.22±0.086; 0.941.67 (+0.33, -0.28)
Midway to RM1360.25±0.106; 0.921.77 (+0.48, -0.38)0.17±0.036; 0.981.48 (+0.11, -0.11)
Under the skin1360.24±0.02§4; 0.99§1.73 (+0.08, -0.08)§0.24±0.066; 0.961.72 (+0.27, -0.23)
  • RM, red muscle.

  • * The thermal rate coefficient (Q10) was estimated from the slope of the linear regression of log10(activity at Tn) vs [(Tn-Tn-1)×0.1], where Tn is the assay temperature (in °C) and the Q10 is equal to 10slope (Schmidt-Nielsen, 1993).

  • Note that the uneven confidence intervals (C.I.) are due to the log10 transformation required to calculate Q10 (see footnote *).

  • Activities measured at 5°C, 15°C and 25°C only.

  • § Activities not determined at 5°C and 10°C.