Table 1

Measured morphological parameters
Kruskal-Wallis main test Kruskal-Wallis pairwise comparison
Parameters Group Mean SEM H P-value
Helmet
Relative helmet length (helmet length/body length) C (n = 17) 0.260 0.004 df = 2 C - N −37.765 <0.001
N (n = 17) 0.384 0.008 H = 47.235 C - T −19.190 0.001
T (n = 21) 0.322 0.004 P = 0.001 N - T 18.574 0.001
Helmet angle [°] C (n = 17) 110.320 0.897 df = 2 C - N −11.706 0.099
N (n = 17) 115.463 0.955 H = 38.662 C - T 20.106 <0.001
T (n = 21) 103.573 0.559 P = 0.001 N - T 31.812 <0.001
Tail-spine
Relative tail-spine length (tail-spine length/body length) C (n = 17) 0.583 0.014 df = 2 C - N −26.529 <0.001
N (n = 17) 0.859 0.019 H = 34.720 C - T 1.756 1
T (n = 21) 0.581 0.008 P = 0.001 N - T 28.286 <0.001
Spine angle (°) C (n = 17) 160.518 1.264 df = 2 C - N −3.471 1
N (n = 17) 162.494 0.811 H = 38.222 C - T 25.61 <0.001
T (n = 21) 143.596 0.844 P = 0.001 N - T 29.081 <0.001
Curvature (absolute/effective spine length) C (n = 17) 1.005 0.001 df = 2 C - N 5.529 0.943
N (n = 17) 1.003 0.000 H = 34.493 C - T −22.964 <0.001
T (n = 21) 1.018 0.001 P = 0.001 N - T −28.493 <0.001
Dorsal ridge
Dorsal ridge width (μm) C (n = 17) 30.391 0.554 df = 2 C - N 0.294 1
N (n = 17) 29.857 0.676 H = 37.094 C - T −26.853 <0.001
T (n = 21) 50.289 0.905 P = 0.001 N - T −27.147 <0.001
Dist. 1. to 10. microspine (μm) C (n = 17) 192.558 3.070 df = 2 C - N 17.000 0.005
N (n = 17) 134.432 3.981 H = 47.016 C - T 35.500 <0.001
T (n = 21) 47.235 1.293 P = 0.001 N - T 18.500 0.001
Max. microspine length (μm) C (n = 17) 39.181 1.690 df = 2 C - N −33.706 <0.001
N (n = 17) 61.260 1.283 H = 39.885 C - T −20.982 <0.001
T (n = 21) 54.249 1.004 P = 0.001 N - T 12.724 0.043
Microspine angle (°) C (n = 17) 19.533 0.906 df = 2 C - N −13.941 0.029
N (n = 17) 28.490 1.243 H = 43.776 C - T −33.971 <0.001
T (n = 21) 78.571 1.307 P = 0.001 N - T −20.029 <0.001

C, non-induced daphnids (control); N, Notonecta-induced daphnids; T, Triops-induced daphnids; SEM, standard error of mean; H, test statistics.

Herzog and Laforsch

Herzog and Laforsch BMC Biology 2013 11:113   doi:10.1186/1741-7007-11-113

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