Publications

distribution and habitat characteristics of manayunkia speciosa and infection prevalence with the parasite ceratomyxa shasta in the klamath river, oregon-california.	a survey for manayunkia speciosa, the freshwater polychaete host for the myxozoan parasite ceratomyxa shasta, was conducted from 2003 to 2005 as part of an integrated study of the epizootiology of ceratomyxosis in klamath river salmonids. substrata samples (n = 257) were collected in a variety of habitats from klamath lake to the mouth of the klamath river to document occurrence and relative abundance of the polychaete by habitat type and to estimate the prevalence of c. shasta within selected p ...	2007	17436945
longevity of ceratomyxa shasta and parvicapsula minibicornis actinospore infectivity in the klamath river.	infectious ceratomyxa shasta and parvicapsula minibicornis actinospores were present in klamath river samples collected in april, may, and june 2005. juvenile chinook salmon oncorhynchus tshawytscha exposed to river water maintained at the ambient klamath river temperature for 0, 4, 24, 72, and 168 h (7 d) developed asymptomatic infections from both parasites. elevated water temperature (18 degrees c) in june may have reduced actinospore viability, as both c. shasta and p. minibicornis infection ...	2007	18201047
distribution and abundance of the salmonid parasite parvicapsula minibicornis (myxozoa) in the klamath river basin (oregon-california, u.s.a.).	the distribution and abundance of the myxosporean parasite parvicapsula minibicornis in the klamath river mirrored that of ceratomyxa shasta, with which it shares both its vertebrate and invertebrate host. assay of fish held at sentinel sites and water samples collected from those sites showed that parasite prevalence was highest below iron gate dam, which is the barrier to anadromous salmon passage. above this barrier parasite levels fluctuated, with the parasite detected in the free-flowing ri ...	2007	18286810
disparate infection patterns of ceratomyxa shasta (myxozoa) in rainbow trout (oncorhynchus mykiss) and chinook salmon (oncorhynchus tshawytscha) correlate with internal transcribed spacer-1 sequence variation in the parasite.	ceratomyxa shasta is a virulent myxosporean parasite of salmon and trout in the pacific northwest of north america. the parasite is endemic in the klamath river, oregon/california, where a series of dams prevent movement of fish hosts between the upper and lower parts of the basin. ceratomyxa shasta exhibits a range of infection patterns in different fish species above and below the dams. we hypothesised that the variations in infection and disease are indicators that different strains of the pa ...	2010	19895812
spatial, temporal and host factors structure the ceratomyxa shasta (myxozoa) population in the klamath river basin.	the myxozoan parasite ceratomyxa shasta is a virulent pathogen of salmonid fish in the klamath river, oregon/california, usa. we previously defined four principal genotypes of the parasite (o, i, ii, iii) based on a trinucleotide repeat (atc)(0-3) in internal transcribed spacer region 1 sequences. genotypes occur in sympatry and show marked host preference: i in chinook salmon (oncorhynchus tschawytscha) and ii in non-native rainbow trout (o. mykiss). in the present study, we sequenced the paras ...	2010	20601174
relationship between temperature and ceratomyxa shasta -induced mortality in klamath river salmonids.	water temperature influences almost every biological and physiological process of salmon, including disease resistance. in the klamath river (california), current thermal conditions are considered sub-optimal for juvenile salmon. in addition to borderline temperatures, these fish must contend with the myxozoan parasite ceratomyxa shasta , a significant cause of juvenile salmonid mortality in this system. this paper presents 2 studies, conducted from 2007 to 2010, that examine thermal effects on ...	2012	22746389
erection of ceratonova n. gen. (myxosporea: ceratomyxidae) to encompass freshwater species c. gasterostea n. sp. from threespine stickleback (gasterosteus aculeatus) and c. shasta n. comb. from salmonid fishes.	ceratonova gasterostea n. gen. n. sp. is described from the intestine of freshwater gasterosteus aculeatus l. from the klamath river, california. myxospores are arcuate, 22.4 ± 2.6 μm thick, 5.2 ± 0.4 μm long, posterior angle 45° ± 24°, with 2 sub-spherical polar capsules, diameter 2.3 ± 0.2 μm, which lie adjacent to the suture. its ribosomal small subunit sequence was most similar to an intestinal parasite of salmonid fishes, ceratomyxa shasta (97%, 1,671/1,692 nucleotides), and distinct from a ...	2014	24754344
transmission and persistence of ceratonova shasta genotypes in chinook salmon.	ceratonova shasta is a myxozoan parasite of salmon and trout transmitted by waterborne actinospores. based on dna sequence data and host specificity, 4 distinct parasite genotypes are recognized. genotypes i and ii are common in the lower reaches of the klamath river, oregon-california, but only infection by genotype i causes mortality in chinook salmon. we conducted sentinel fish exposures and determined genotype composition in river water during exposure, and in fish gills, intestine, and tank ...	2014	24945751
production of ceratonova shasta myxospores from salmon carcasses: carcass removal is not a viable management option.	severe infection by the endemic myxozoan parasite, ceratonova (synonym, ceratomyxa) shasta, has been associated with declines in and impaired recovery efforts of populations of fall-run chinook salmon oncorhynchus tshawytscha in the klamath river, california. the parasite has a complex life cycle involving a polychaete worm host as well as a salmon host. myxospore transmission of this parasite, from salmon to polychaete, is a life cycle step during which there is a potential for applied disease ...	2016	27064587
molecular evidence of undescribed ceratonova sp. (cnidaria: myxosporea) in the freshwater polychaete, manayunkia speciosa, from western lake erie.	we used pcr to screen pooled individuals of manayunkia speciosa from western lake erie, michigan, usa for myxosporean parasites. amplicons from positive pcrs were sequenced and showed a ceratonova species in an estimated 1.1% (95% ci=0.46%, 1.8%) of m. speciosa individuals. we sequenced 18s, its1, 5.8s, its2 and most of the 28s rdna regions of this ceratonova sp., and part of the protein-coding ef2 gene. phylogenetic analyses of ribosomal and ef2 sequences showed the lake erie ceratonova sp. is ...	2016	27150245