Christine Densmore (Former Employee)

Three strains of rainbow trout and steelhead Oncorhynchus mykiss were evaluated for the presence of whirling disease in field and laboratory trials. In the field exposures, fingerling Salmon River steelhead and Cayuga Lake and Randolph strains of rainbow trout were placed in wire cages in an earthen, stream-fed pond in New York State that was known to harbor Myxobolus cerebralis. Control...

Three strains of rainbow trout and steelhead Oncorhynchus mykiss were evaluated for the presence of whirling disease in field and laboratory trials. In the field exposures, fingerling Salmon River steelhead and Cayuga Lake and Randolph strains of rainbow trout were placed in wire cages in an earthen, stream-fed pond in New York State that was known to harbor Myxobolus cerebralis. Control...

Hematological responses to whirling disease in rainbow trout (Oncorhynchus mykiss) were investigated. Two-mo-old fingerling rainbow trout were exposed to cultured triactinomyxon spores of Myxobolus cerebralis at 9,000 spores/fish in December, 1997. Twenty-four wks post-exposure, fish were taken from infected and uninfected groups for peripheral blood and cranial tissue sampling...

Fish morbidity and mortality events in Chesapeake Bay tributaries have aroused concern over the health of this important aquatic ecosystem. We applied a recently described method for quantifying mRNA of an immunosuppressive cytokine, transforming growth factor-β (TGF-β), by reverse transcription quantitative-competitive polymerase chain reaction to a field study of fish health in the...

Salmonid whirling disease is caused by Myxobolus cerebralis, a metazoan parasite with a two host life cycle involving salmonid fish a an aquatic oligochaete, Tubifex tubifex (Wolf, Markiw and Hiltunen, 1986). Whirling disease has been reported in 22 U.S. states with the greatest losses occurring in the salmonid fisheries of western and Midwestern states. Although whirling disease is...

Whirling disease is caused by Myxobolus cerebralis and requires an intermediate oligochaete host identified as Tubifex tubifex (Wolf, Markiw, and Hiltunen, 1986). M. cerebralis spores ingested by the tubifex worms develop into triactinomyxons (tams) that are eventually released into the water column to infect salmonid fish. There may be many environmental parameters, biotic or abiotic...

We have described in previous reports (Schill et al., 1998) the development of a polymerase chain reaction (PCR) amplification of 18S ribosomal RNA for the detection of Myxozoan parasites. Oligonucleotide primers were developed by multiple alignment of Myxozoan sequence information and analysis by a custom-written computer program (PRIM). Candidate pairs of primer sequences were then...

During the summer and fall of 1997, an unusually high prevalence of skin lesions in fishes from Chesapeake Bay tributaries as well as two fish kills in the Pocomoke River stimulated significant public concern. Atlantic menhaden Brevoortia tyrannus were the most frequent target of the acute fish kills and displayed skin lesions that were attributed to the presence of the toxic...