SOME TREMATODE, NEMATODE, AND ACANTHOCEPHALAN PARASITES OF RAINBOW-TROUT, ONCORHYNCHUS-MYKISS, INTRODUCED INTO CHILE

The gastrointestinal tracts of 211 adult Oncorhynchus mykiss (Walbaum, 1792) were examined for trematode, nematode, and acanthocephalan para sites from 8 lakes in southern Chile (between 41 degrees 05' and 39 de grees 03' south latitude). The parasites Derogenes patagonicus, Acanth ostomoides apophalliformis, Camallanus corderoi, Hysterothylacium sp., Acanthocephalus tumescens, and Acanthocephalus sp. were present. Cama llanus corderoi and Lf, patagonicus were present in 8 and 6 lakes, res pectively. In 6 lakes, the prevalence was higher for C. corderoi compa red to 2 other lakes. In 3 different lakes, the mean intensities were higher for D. patagonicus (Lakes Rupanco, Puyehue, and Maihue) and C. corderoi (Lakes Ranco, Colico, and Caburga) with respect to other spec ies. Acanthocephalans were infrequent in rainbow trout, except for A. tumescens in Lake Villarrica.