The frequency of Ceratonova shasta genotypes in Manayunkia speciosa host genotypes

Ceratonova shasta is a myxozoan parasite that affects populations of salmonid species in the Pacific Northwest and is the cause of enteronecrosis. It has a complex life cycle involving two hosts; a definitive annelid host, Manayunkia speciosa (polychaete), and an intermediate salmonid host. Klamath River M. speciosa are genetically variable and genetic variability in at least one other invertebrate host has been correlated with parasite susceptibility: genetic variation in Tubifex tubifex is correlated with susceptibility to infection by the myxozoan Myxobolus cerebralis, the causative agent of salmonid whirling disease. This research looked at the genetic variation of M. speciosa in the Klamath River, Oregon with the aim of correlating C. shasta genotype to definitive host genotype in order to aid in risk assessment of the Klamath River system. This research found that C. shasta genotype II was more associated with M. speciosa infection than genotype I