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Table 3 Fixed effects of general and generalized linear models for infection levels in eight Tropheus populations

From: Contrasting parasite communities among allopatric colour morphs of the Lake Tanganyika cichlid Tropheus

    

Infection presence

Abundance

Infection intensity

Parasite group

Effect

Num DF

Den DF

F

P

F

P

F

P

Acanthocephalans

site

7

605/483

9.01

< 0.0001

23.46

< 0.0001

11.92

< 0.0001

 

day

2

605/483

0.76

0.4673

1.02

0.3622

01.25

0.2886

 

sex

1

605/483

0.01

0.9100

0.04

0.8484

0.04

0.8351

 

SL

1

605/483

12.62

0.0004

57.06

< 0.0001

47.92

< 0.0001

 

year(site)

6

605/483

5.02

< 0.0001

7.57

< 0.0001

5.02

< 0.0001

Nematodes

site

7

605/47

2.38

0.0210

2.64

0.0106

1.32

0.2640

 

day

2

605/47

0.63

0.5336

0.78

0.4591

2.41

0.1005

 

sex

1

605/47

1.09

0.2974

1.36

0.2434

1.17

0.2843

 

SL

1

605/47

0.10

0.7557

0.05

0.8185

1.39

0.2436

 

year(site)

6

605/47

0.89

0.5011

2.19

0.0428

0.74

0.6009

Gyrodactylus

site

7

616/24

3.95

0.0003

5.47

< 0.0001

0.83

0.5692

 

day

2

616/24

0.90

0.4091

0.37

0.6927

4.88

0.0167

 

sex

1

616/24

0.30

0.5811

0.09

0.7607

1.16

0.2926

 

SL

1

616/24

0.26

0.6093

0.27

0.6016

1.25

0.2751

.

year(site)

6

616/24

0.35

0.9071

0.60

0.7344

0.93

0.4933

Cichlidogyrus

site

7

476/418

2.85

0.0064

18.85

< 0.0001

15.14

< 0.0001

 

day

2

476/418

2.80

0.0617

5.50

0.0043

2.54

0.0803

 

sex

1

476/418

3.62

0.0578

7.58

0.0061

4.00

0.0462

 

SL

1

476/418

6.60

0.0105

77.90

< 0.0001

74.38

< 0.0001

 

year(site)

6

476/418

2.80

0.0108

3.68

0.0014

1.73

0.1131

Ergasilus

site

7

476/158

1.73

0.1001

2.40

0.0201

1.86

0.0792

 

day

2

476/158

0.70

0.4984

0.14

0.8729

1.36

0.2602

 

sex

1

476/158

0.15

0.6978

0.10

0.7479

0.00

0.9537

 

SL

1

476/158

0.58

0.4485

3.28

0.0708

5.30

0.0227

 

year(site)

6

476/158

0.70

0.6489

0.55

0.7696

0.23

0.9667

  1. Fixed effects included sampling site, processing day, sex, standard length (SL), and sampling year (nested in site). Observer effects were included as random (not shown), except for Gyrodactylus sp. for which there was only one observer. The model for infection presence assumes a binomial distribution and models the logit of the probability of infection. For the models for abundance and infection intensity, the dependent variable was square-root transformed. Note that the denominator degrees of freedom (Den DF) are higher for the infection presence and abundance model (before the dash) than for the infection intensity model (after the dash). P-values in bold indicate significance at α = 0.05.
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BMC Ecology and Evolution

ISSN: 2730-7182

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