title: The life history of Nezpercella lewisi Schell 1974 (Trematoda: Opecoelidae), a parasite of the northern squawfish, and the smallmouth bass.
abstract: Nezpercella lewisi is an intestinal parasite of Ptychocheilus oregonensis and Micropterus dolomieui in Idaho. The miracidium develops and hatches within 12 to 14 days at 22 to 26 C or within 50 to 60 days at 12 to 15 C. Cotylomicrocercous cercariae develop in daughter sporocysts in Lithoglyphys virens and encyst in fry of Richardsonius balteatus, Rhinichthys cataractae, R. osculus, Ptychocheilus oregonensis, Cottus rhotheus, and Salmo gairdneri. Natural infections with metacercariae were found in all of the above fishes except speckled dace and trout. Squawfish were fed fry of experimentally infected redside shiner and squawfish and partially developed specimens of N. lewisi recovered 8 weeks later. The larval stages are like those of trematodes in the family Ppecoelidae to which the species is transferred.
mesh_terms: D000818:Animals; D005399:Fishes / Q000469:parasitology*; D014200:Trematoda / Q000033:anatomy & histology / Q000254:growth & development*