TABLE 4.2Percentage of Vertebrate Species Listed as Threatened by IUCN Red List and the Estimated Numbers of Parasitic Helminth Species That This Puts at Risk of Extinction (upper) [Poulin and Morand (2004), Who Assume That the Proportion of Parasite Species at Risk Equals the Proportion of Hosts at Risk], and Proportion of Parasites at Risk When Corrected for Different Levels of Host Specificity Exhibited by Each Parasite Taxa in Each Host Taxa (lower)

Parasite SpeciesHost Species (% of host species listed as threatened)
Chondrichthys
(2)		Osteichthys
(2)		Amphibia
(2)		Reptilia
(3)		Aves
(11)		Mammalia
(11)		Total
No. of parasite species at risk
Trematoda1117231131,0854091,748
Cestoda27896331,5465102,211
Acanthocephala—25368633153
Nematoda353531921,0073281,636
Trematoda118464365203656
Cestoda1614115655270971
Acanthocephala—20110820
Nematoda15109030754468
Totals (%)18 (1.13)39 (0.28)16 (0.38)170 (1.48)1,338 (3.95)535 (4.60)2,115 (2.75)

From: 4, Homage to Linnaeus: How Many Parasites? How Many Hosts?

Cover of In the Light of Evolution
In the Light of Evolution: Volume II: Biodiversity and Extinction.
National Research Council (US); Avise JC, Hubbell SP, Ayala FJ, editors.
Washington (DC): National Academies Press (US); 2008.
Copyright 2008 by the National Academy of Sciences. All rights reserved.

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