Age‐Dependent Susceptibility of Chinook Salmon to Myxobolus cerebralis and Effects of Sustained Parasite Challenges

Abstract Laboratory challenges with triactinomyxons of Myxobolus cerebralis demonstrate that Chinook salmon Oncorhynchus tshawytscha have a lower susceptibility to infection and the development of whirling disease than rainbow trout O. mykiss. In age-dependent challenges, triplicate groups of each species were exposed at 1, 3, 5, 7, and 9 weeks posthatch to 1,000 triactinomyxons per fish and juvenile Chinook salmon were exposed to a high dose of 10,000 triactinomyxons per fish. Assessment of infection at 5 months postchallenge showed that Chinook salmon acquire resistance to clinical disease after 3 weeks posthatch, as compared with 7 weeks posthatch for rainbow trout. Furthermore, all measures of infection severity, including myxospore burden and lesion score, were lower in Chinook salmon. To model natural exposure and evaluate the ability of the fish to retain resistance following repeated challenge, replicate groups of Chinook salmon and rainbow trout were exposed daily to low parasite doses (5–200 tri...

[1]  S. Feist,et al.  Bartholomew, J. L. 2001. Salmonid Ceratomyxosis.in J. C. Thoesen, editor. Suggested Procedures for the Detection and Identification of Certain Finfish and Shellfish Pathogens, Blue Book 4th Edition. Fish Health Section, American Fisheries Society. , 2004 .

[2]  Sarah A. Sollid.  Susceptibility of select salmonids to Myxobolus cerebralis and effects of exposure on anadromous salmonids in Oregon , 2002 .

[3]  D. G. Stevens,et al.  Dynamics of Myxobolus cerebralis in the Lostine River, Oregon: Implications for Resident and Anadromous Salmonids , 2001 .

[4]  M. Georgiadis,et al.  Susceptibility of three species of anadromous salmonids to experimentally induced infections with Myxobolus cerebralis, the causative agent of whirling disease. , 2001 .

[5]  M. Georgiadis,et al.  Susceptibility of Selected Inland Salmonids to Experimentally Induced Infections with Myxobolus cerebralis, the Causative Agent of Whirling Disease , 1999 .

[6]  M. Georgiadis,et al.  Comparative susceptibility of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta to Myxobolus cerebralis, the cause of salmonid whirling disease. , 1999, Diseases of aquatic organisms.

[7]  M. El-Matbouli,et al.  Whirling disease: host specificity and interaction between the actinosporean stage of Myxobolus cerebralis and rainbow trout Oncorhynchus mykiss. , 1999, Diseases of aquatic organisms.

[8]  M. El-Matbouli,et al.  Whirling disease: re‐emergence among wild trout , 1998, Immunological reviews.

[9]  K. Andree,et al.  A nested polymerase chain reaction for the detection of genomic DNA of Myxobolus cerebralis in rainbow trout Oncorhynchus mykiss. , 1998, Diseases of aquatic organisms.

[10]  J. Bartholomew.  Host Resistance to Infection by the Myxosporean Parasite Ceratomyxa shasta: A Review , 1998 .

[11]  M. El-Matbouli,et al.  Light and electron microscopic observations on the route of the triactinomyxon-sporoplasm of Myxobolus cerebralis from epidermis into rainbow trout cartilage , 1995 .

[12]  M. E. Markiw.  Experimentally Induced Whirling Disease I. Dose Response of Fry and Adults of Rainbow Trout Exposed to the Triactinomyxon Stage of Myxobolus cerebralis , 1992 .

[13]  M. E. Markiw.  Whirling disease: earliest susceptible age of rainbow trout to the triactinomyxid of Myxobolus cerebralis , 1991 .

[14]  K Wolf,et al.  Biology Contravenes Taxonomy in the Myxozoa: New Discoveries Show Alternation of Invertebrate and Vertebrate Hosts , 1984, Science.

[15]  K. Wolf,et al.  Myxosoma cerebralis (Myxozoa: Myxosporea) Etiologic Agent of Salmonid Whirling Disease Requires Tubificid Worm (Annelida: Oligochaeta) in its Life Cycle , 1983 .

[16]  J. Wales,et al.  Microscopic anatomy of salmonids : an atlas , 1983 .

[17]  J. O'Grodnick.  Susceptibility of Various Salmonids to Whirling Disease (Myxosoma cerebralis) , 1979 .

[18]  K. Wolf,et al.  Myxosoma cerebralis: Isolation and Concentration from Fish Skeletal Elements — Sequential Enzymatic Digestions and Purification by Differential Centrifugation , 1974 .

[19]  G. Hoffman,et al.  Host Susceptibility and the Effect of Aging, Freezing, Heat, and Chemicals on Spores of Myxosoma Cerebralis , 1969 .