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High‐prevalence and low‐intensity Ichthyophonus infections in Pacific Halibut

March 1, 2018

Ichthyophonus occurred at high prevalence but low intensity in Pacific Halibut Hippoglossus stenolepis throughout the West Coast of North America, ranging from coastal Oregon to the Bering Sea. Infection prevalence in adults was variable on spatial and temporal scales, with the lowest prevalence typically occurring on the edges of the geographic range and highest prevalence consistently occurring inside Prince William Sound, Alaska (58–77%). Additionally, intra‐annual differences occurred at Albatross–Portlock, Alaska (71% versus 32% within 2012), and interannual differences occurred along coastal Oregon (50% in 2012 versus 12% in 2015). The infection prevalence was influenced by host age, increasing from 3% or less among the youngest cohorts (age ≤ 6) to 39–54% among age‐9–17 cohorts, then decreasing to 27% among the oldest (age‐18+) cohorts. There was little indication of significant disease impacts to Pacific Halibut, as the intensity of infection was uniformly low and length at age was similar between infected and uninfected cohorts. These results suggest that Ichthyophonus in Pacific Halibut currently represents a stable parasite–host paradigm in the North Pacific.

Citation Information

Publication Year 2018
Title High‐prevalence and low‐intensity Ichthyophonus infections in Pacific Halibut
DOI 10.1002/aah.10011
Authors Paul Hershberger, Jacob L. Gregg, Claude L. Dykstra
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Aquatic Animal Health
Series Number
Index ID 70196370
Record Source USGS Publications Warehouse
USGS Organization Western Fisheries Research Center