Table 2 Results from linear models testing the relationship between sperm swimming speed (i.e. VCL) and a number of sperm morphological traits in (a) P. a. acuticauda and (b) P. a. hecki

−1.03 ± 0.8

−1.28

0.22

1.14 ± 0.27

4.20

0.0008

0.44 ± 0.55

0.80

0.44

0.44 ± 0.72

0.61

0.55

0.44 ± 0.38

1.16

0.26

1.59 ± 0.52

3.04

0.008

−1.27 ± 0.70

−1.80

0.09

1.03 ± 0.09

11.13

<0.0001

1.10 ± 0.16

6.79

<0.0001

1.44 ± 0.21

6.73

<0.0001

0.82 ± 0.15

5.60

<0.0001

78.57 ± 39.56

1.99

0.06