title: Parasites of fishes in the Colorado River and selected tributaries in Grand Canyon, Arizona.
abstract: As part of the endangered humpback chub (HBC; Gila cypha ) Adaptive Management Program, a parasite survey was conducted from 28 June to 17 July 2006 in 8 tributaries and 7 adjacent sections of the main stem of the Colorado River, U.S.A. In total, 717 fish were caught, including 24 HBC. Field necropsies yielded 19 parasite species, 5 of which (Achtheres sp., Kathlaniidae gen. sp., Caryophyllaidae gen. sp., Myxidium sp., and Octomacrum sp.) are new records for Grand Canyon, Arizona, U.S.A. Spearman's correlation coefficient analyses showed no correlations between parasite burden and fork length for various combinations of fish and parasite species. Regression analyses suggest that no parasite species had a strong effect on fish length. The most diverse parasite community (n = 14) was at river kilometer (Rkm) 230, near the confluence of Kanab Creek. The most diverse parasite infracommunity (n = 12) was found in the non-native channel catfish (CCF; Ictaluris punctatus). Overall parasite prevalence was highest in CCF (85%) followed by that in HBC (58%). The parasite fauna of humpback chub was mainly composed of Bothriocephalus acheilognathi and Ornithodiplostomum sp. metacercariae.
authors.affiliation: Department of Biology, University of Wisconsin-La Crosse, La Crosse, Wisconsin 54601, USA.
authors.forename: Chad M
authors.initials: CM
authors.lastname: Linder
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Cole
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Hoffnagle
authors.forename: Bill
authors.initials: B
authors.lastname: Persons
authors.forename: Anindo
authors.initials: A
authors.lastname: Choudhury
authors.forename: Roger
authors.initials: R
authors.lastname: Haro
authors.forename: Mauritz
authors.initials: M
authors.lastname: Sterner
mesh_terms: D000818:Animals; D001130:Arizona; D003063:Cnidaria / Q000145:classification*; D003530:Cyprinidae / Q000469:parasitology*; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes; D007059:Ictaluridae / Q000469:parasitology*; D010273:Parasitic Diseases, Animal / Q000469:parasitology*; D010986:Platyhelminths / Q000145:classification* / Q000302:isolation & purification; D012044:Regression Analysis; D045483:Rivers; D018709:Statistics, Nonparametric