Parasites of hardhead (Mylopharodon conocephalus) and Sacramento pikeminnow (Ptychocheilus grandis) from the North Fork Feather River, Plumas and Butte Counties, California

Hardhead (Mylopharodon conocephalus) and Sacramento pikeminnow (Ptychocheilus grandis) are endemic to California and are native to the Sacramento-San Joaquin system, Russian River, and Napa River. Very little study has been done on parasites of these two species. The objective of this study was to describe the parasites of hardhead and Sacramento pikeminnow in the North Fork Feather River in Plumas and Butte Counties, between its confluence with the East Branch of the North Fork Feather and Lake Oroville. Thirty-two hardhead and 14 Sacramento pikeminnow were examined for parasites. All Sacramento pikeminnow were infected, and all but one hardhead were infected. On average, Sacramento pikeminnow were infected with four parasites, and hardhead were infected with three parasites. I found six new host records for hardhead and four new host records for Sacramento pikeminnow. I found Trichodina/Paratrichodina species in Sacramento pikeminnow and two Myxobolus species in hardhead and Sacramento pikeminnow. Dactylogyrus californiensis and one unidentified monogenetic trematode were found on hardhead. I found Neascus of Ornithodiplostomum ptychocheilus in both hardhead and Sacramento pikeminnow. I found Edlintonia ptychocheila and Neoechinorhynchus rutili in hardhead. In addition, I found one parasite which has been previously recorded in hardhead and Sacramento pikeminnow, Lernaea cyprinacea. I also found three types of parasites which have been previously recorded in hardhead and Sacramento pikeminnow. "Black spot" Neascus species and unidentified larval nematodes were found in both hardhead and Sacramento pikeminnow, and unidentified proteocephalan plerocercoids were found in Sacramento pikeminnow.