Table 2 Parasite abundance (A, mean ± SD), prevalence (P) and intensity of infection (II, max–min) for each group of fish groups ((Rutilus rutilus, Abramis brama, backcross generation with roach in paternal position (abbreviated as backcross R. rutilus), backcross generation with common bream in paternal position (abbreviated as backcross A. brama))

D. crucifer

108.44 ± 115.38

100

6–374

–

–

–

87.93 ± 56.02

100

3–188

7.15 ± 12.72a*

54b*

1–36a*

D. caballeroi

5.44 ± 12.29

44

1–48

–

–

–

4.40 ± 3.74

67

3–10

0.77 ± 1.36

31

1–4

D. rutili

5.94 ± 9.93

72

1–33

–

–

–

4.27 ± 6.05

67

1–19

1.08 ± 1.89a

31b

2–3

D. nanus

8.00 ± 9.78

83

1–33

–

–

–

2.53 ± 4.60a

40b

1–12

0.46 ± 1.20a*

15b*

2–4

D. suecicus

4.28 ± 11.79

39

1–48

–

–

–

1.13 ± 1.51

47

1–5

0.15 ± 0.55

8

2

D. fallax

1.22 ± 2.56

33

1–10

–

–

–

–

–

–

–

–

–

D. similis

3.78 ± 5.34

56

1–16

–

–

–

1.13 ± 1.51

40

2–4

0.23 ± 0.60a

15b

1–2

D. sphyrna

3.83 ± 5.27

61

1–18

–

–

–

3.33 ± 4.70

47

2–14

0.54 ± 1.05a

23b

2–3

D. rarissimus

2.17 ± 4.89

28

4–20

–

–

–

0.73 ± 1.33

27

2–4a

–

–

–

D. auriculatus

–

–

–

21.08 ± 45.40

100

2–171

0.13 ± 0.52c*

7d*

2f*

17.69 ± 19.17

77

2–57

D. wunderi

–

–

–

13.69 ± 14.01

92

1–41

–

–

–

14.85 ± 22.65

85

1–83

D. zandti

–

–

–

174.15 ± 145.69

100

30–471

0.47 ± 0.92c*

27d*

1–3c*

42.38 ± 39.70c*

100

5–146c*

D. falcatus

–

–

–

15.00 ± 12.35

85

4–37

0.13 ± 0.35c*

13d*

1c

12.92 ± 13.77

85

2–40

G. vimbi

47.06 ± 101.19

78

1–398

8.23 ± 11.25

62

2–36

63.00 ± 124.94

67

6–496c

31.92 ± 65.61

85

1–238

G. carassii

7.94 ± 14.72

61

1–52

0.23 ± 0.83

8

3

0.13 ± 0.52a

7b*

2

–

–

–

G. elegans

–

–

–

1.92 ± 3.20

38

1–10

1.47 ± 5.68

7d

22

5.08 ± 17.41

23

1–63

P. homoion

12.72 ± 19.74

50

1–67

2.00 ± 4.26

31

1–12

1.27 ± 2.63

27

2–8a

0.85 ± 1.72

23

2–5