Parasites of largemouth bass (Micropterus salmoides) in Northern California

A total of fifty largemouth bass (Micropterus salmoides) were collected from Clear Lake, Lake Berryessa, Lake Sonoma, Trinity Lake and the Sacramento–San Joaquin River Delta. All fish were infected with at least one parasite, with the exception of one juvenile fish from Trinity Lake in which no parasites were found. The following parasites were observed in largemouth bass: Actinocleiudus unguis, Clavunculus bursatus, Clinostomum complanatum, Proteocephalus pearsei, Contracaecum sp., Hysterothylacium (?) sp., Spinitectus carolini, Camallanus sp., Neoechinorhynchus cylindratus, Myzobdella lugubris, Batracobdella phalera, Ergasilus centrarchidarum, and Argulus flavescens. In addition to these identified parasites, I also found an unidentified leech and Proteocephalus sp. plerocercoids, which could not be identified to species. All of these parasites have been previously reported infecting largemouth bass. Clinostomum complanatum, Contracaecum sp. and Myzobdella lugubris, have been previously reported in California; but these are the first known reports from largemouth bass in California. Actinocleidus unguis was the only parasite found that has previously been reported to infect largemouth bass in California.