Parasite biogeography: A review of the origins and ideas with specific examples from Holarctic fishes

Citation
Jp. Carney et Ta. Dick, Parasite biogeography: A review of the origins and ideas with specific examples from Holarctic fishes, VIE MILIEU, 50(4), 2000, pp. 221-243
Citations number
126
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Environment/Ecology
Journal title
VIE ET MILIEU-LIFE AND ENVIRONMENT
ISSN journal
0240-8759 → ACNP
Volume
50
Issue
4
Year of publication
2000
Pages
221 - 243
Database
ISI
SICI code
0240-8759(200012)50:4<221:PBAROT>2.0.ZU;2-#
Abstract
The origins and major ideas underpinning parasite biogeography started in w estern Europe and North America with von Ihering who used parasites to stud y host distributions. A similar approach was used by Metcalf, Johnston, Har rison and Manter whereas Dogiel and coworkers used parasites of fish to rec ognize different biogeographic zones. More recently, Brooks advanced the fi eld by introducing phylogenetic systematics as a method to investigate para site biogeography and historical ecology. Although infrequently combined to date, two complementary approaches to parasite biogeography are historical and ecological. Historical biogeography considers questions relating to th e origins of parasite distributions and host associations while ecological biogeography is concerned with contemporary factors that contribute to pres ent distributions and abundances. Data from Holarctic fishes are used to ou tline ideas relevant to parasite ecological biogeography at the scale of co ntinental distributions. These data support the hypothesis that most of the parasites have continental distributions even though the hosts have interc ontinental distributions. While hosts contribute to the distribution of par asites, many parasites of Holarctic fishes show stronger affinities to geog raphy than to the host. This suggests that parasite distributions, although ultimately dependant on a host, are influenced by factors in addition to h ost factors. Strict host-specificity does not confirm coevolutionary roots for predictable host-parasite associations. However, predictable associatio ns exist at higher taxonomic levels and these may or may not have coevoluti onary origins. Widespread parasite distributions can be a consequence of ha ving numerous hosts across taxa. Historical ecological associations and sym patric hosts sharing food items that transmit parasites, ensures homogeniza tion of the parasitofauna. Predictable associations at higher host taxonomi c levels, combined with widespread Holarctic distributions at higher parasi te taxonomic levels, suggests an ancient origin for many of these parasite species. These observations are true for parasites of Holarctic fish specie s and may also be true for fish parasites in the north-south axis of the ma jor continents. The combination of widespread distribution of parasite spec ies with numerous fish hosts, and endemic parasite species with restricted geographic and host associations, makes parasites fruitful models for compr ehensive biogeographic studies.