Table 2.

Overall prevalence of the trematode species (% of infected snails in the pooled samples from 2012 and 2013) infecting the six snail species in the River Ruhr.

Snail species	Trematode family	Trematode species	2nd intermediate host	Definitive host	Lake
					Baldeneysee	Hengsteysee	Sorpetalsperre	Hennetalsperre	Versetalsperre	TOTAL
Radix auricularia	Cyclocoelidae	Cyclocoelum sp.*	Molluscs (first intermediate host acts as second intermediate host)	Rallid birds	0.3	4.1	0.9	—	—	2.3
	Diplostomidae	Diplostomum baeri	Fishes	Fish-eating birds	—	0.1	—	—	—	0.1
		Diplostomum sp. “Clade Q”	Fishes	Fish-eating birds	—	0.1	—	—	—	0.1
		Diplostomum mergi 2*†	Fishes	Fish-eating birds	0.3	0.7	1.2	—	—	0.6
		Diplostomum mergi 3†	Fishes	Fish-eating birds	—	0.4	—	—	—	0.2
		Diplostomum mergi 4	Fishes	Fish-eating birds	—	0.1	—	—	—	0.1
		Diplostomum parviventosum	Fishes	Fish-eating birds	—	1.0	—	—	—	0.5
		Diplostomum spathaceum†	Fishes	Fish-eating birds	—	0.7	—	—	—	0.4
		Tylodelphys clavata*†	Fishes	Fish-eating birds	1.1	1.2	1.8	3.1		1.5
	Echinostomatidae	Echinoparyphium aconiatum*†	Molluscs	Waterfowl	—	0.2	0.3	3.5	—	0.6
		Echinoparyphium recurvatum*†	Molluscs	Waterfowl	0.3	1.5	13.0	3.9	—	3.6
		Echinostoma revolutum*	Molluscs	Waterfowl	—	—	—	2.3	—	0.3
		Echinostoma sp. IG	Molluscs	Waterfowl	0.3	—	0.3	—	—	0.1
		Petasiger radiatus* †a	Fishes	Fish-eating birds	12.0	9.9	11.5	6.6	—	10.2
	Notocotylidae	Notocotylus attenuatus*†	None (cercariae encyst on vegetation)	Waterfowl	0.8	2.2	4.4	4.7	—	2.7
	Plagiorchiidae	Plagiorchis elegans*	Larval insects, amphipods, molluscs	Various birds, mammals	—	7.0	4.7	4.7	—	4.9
	Sanguinicolidae	Sanguinicola inermis	None (direct life cycle)	Cyprinids	—	—	1.2	—	—	0.2
	Schistosomatidae	Trichobilharzia franki*†	None (direct life cycle)	Waterfowl	0.6	0.4	5.0	0.4	—	1.3
	Strigeidae	Apatemon gracilis	Fishes	Fish-eating birds	—	0.11	—	—	—	0.1
		Australapatemon burti †	Leeches	Waterfowl	0.27	1.0	0.9	—	—	0.7
		Cotylurus brevis	Molluscs, leeches	Waterfowl	—	—	—	0.8	—	0.1
		Cotylurus cornutus*†	Molluscs, leeches	Waterfowl	—	0.6	1.2	—	—	0.5
	Telorchiidae	Opisthioglyphe ranae	Amphibians	Amphibians	0.8	0.3	—	0.4	—	0.4
Radix peregra	Echinostomatidae	Echinoparyphium recurvatum*	Molluscs	Waterfowl	—	—	—	13.9	1.6	2.9
		Echinostoma revolutum*	Molluscs	Waterfowl	—	—	—	16.7	—	1.7
		Petasiger radiatusa	Fishes	Fish-eating birds	—	—	—	11.1	—	1.2
	Notocotylidae	Notocotylus attenuatus	None (cercariae encyst on vegetation)	Waterfowl	—	—	—	2.8	—	0.3
	Plagiorchiidae	Plagiorchis elegans	Molluscs, larval insects, crustaceans	Various birds, mammals	—	—	—	2.8	0.6	0.9
	Strigeidae	Cotylurus sp.	Molluscs, leeches	Waterfowl	—	—	—	2.8	—	0.3
Lymnaea stagnalis	Diplostomidae	Diplostomum pseudospathaceum*	Fishes	Fish-eating birds	13.9	10.6	—	—	—	11.0
		Tylodelphys clavata	Fishes	Fish-eating birds	5.6		—	—	—	0.8
	Schistosomatidae	Trichobilharzia szidati	None (direct life cycle)	Waterfowl		1.0	—	—	—	0.8
	Telorchiidae	Opisthioglyphe ranae	Amphibians	Amphibians	2.8	1.4	—	—	—	1.6
Stagnicola palustris	Cyclocoelidae	Cyclocoelum sp.*	Molluscs (first intermediate host acts as second intermediate host)	Rallid birds	—	8.9	—	—	—	8.2
	Diplostomidae	Diplostomum pseudospathaceum*	Fishes	Fish-eating birds	5.7	2.6	—	—	—	2.7
		Tylodelphys clavata	Fishes	Fish-eating birds	2.9	0.2	—	—	—	0.3
	Echinostomatidae	Echinoparyphium recurvatum	Molluscs	Waterfowl	—	0.2	—	—	—	0.2
		Echinostoma revolutum	Molluscs	Waterfowl	—	0.2	—	—	—	0.2
	Lissorchiidae	Asymphylodora tincae	None	Cyprinids	—	0.2	—	—	—	0.2
	Plagiorchiidae	Plagiorchis elegans	Molluscs, larval insects, crustaceans	Various birds, mammals	—	0.3	5.6	—	—	0.5
	Schistosomatidae	Schistosomatidae gen. sp. 4	None (direct life cycle)	Waterfowl	—	0.2	—	—	—	0.2
	Telorchiidae	Opisthioglyphe ranae	Amphibians	Amphibians	8.6	0.3	—	—	—	0.8
Gyraulus albus	Diplostomidae	Hysteromorpha triloba	Fishes	Fish-eating birds	—	3.6	—	3.3	—	3.3
		Tylodelphys excavata	Amphibians	Storks	5.3	—	—	—	—	0.1
	Echinostomatidae	Neopetasiger sp. 1b	Fishes	Fish-eating birds	—	—	—	0.2	—	0.2
		Neopetasiger sp. 2b	Fishes	Fish-eating birds	—	—	—	0.1	—	0.1
		Neopetasiger sp. 3b	Fishes	Fish-eating birds	—	3.6	—	0.1	—	0.2
		Petasiger radiatusa	Fishes	Fish-eating birds	26.3	—	—	2.2	—	2.4
	Schistosomatidae	Schistosomatidae gen. sp. 1	None (direct life cycle)	Waterfowl	—	—	—	0.1	—	0.1
		Schistosomatidae gen. sp. 2	None (direct life cycle)	Waterfowl	—	—	—	0.2	—	0.2
	Strigeidae	Australapatemon burti*	Leeches	Waterfowl	—	—	—	7.5	16.7 c	7.3
		Cotylurus sp.	Molluscs, leeches	Waterfowl	10.5	—	—	—	—	0.1
Segmentina nitida	Diplostomidae	Hysteromorpha triloba	Fishes	Fish-eating birds	—	—	—	0.6	—	0.5
	Schistosomatidae	Schistosomatidae gen. sp. 3	None (direct life cycle)	Waterfowl	—	—	—	0.6	—	0.5
	Strigeidae	Australapatemon burti	Leeches	Waterfowl	—	—	—	1.1	—	1.0

Lakes where prevalence was zero or no suitable host populations were found are indicated by a minus (−). Intermediate and definitive hosts are provided based on literature data^{58,59,62,68–72}.

^aSyn. Paryphostomum radiatum⁷³.

^bDescribed as Petasiger spp. 1–3 by Selbach et al.³⁸.

^cSample size small (n < 14).

*Dominant species, i.e. with a prevalence ≥ 10% in at least one component community.

^†Most common species in the guilds of waterfowl and fish-eating bird parasites that were used in the ANCOVAs.