title: Infection patterns of Tylodelphys barilochensis and T. crubensis (Trematoda: Diplostomatidae) metacercariae in Galaxias maculatus (Osmeriformes: Galaxiidae) from two Patagonian lakes and observations on their geographical distribution in the southern Andean region, Argentina.
abstract: In the Patagonian Andean region, 2 species of diplostomatids parasitize the brains of Galaxias maculatus. The purpose of this study was to evaluate seasonal variation, spatial variation, and association with host age in the transmission of Tylodelphys barilochensis and T. crubensis in several oligotrophic lakes in Argentinian Patagonia. Fishes were captured monthly in Lake Gutiérrez and bimonthly in Lake Escondido. One summer or autumn sample was also taken in several other Patagonian lakes. Infection parameters were calculated and compared using nonparametric tests. The 2 species co-occurred in most of the sampled lakes, with high values of prevalence and mean intensity. In Lake Gutiérrez and Lake Escondido, the intensity of both diplostomatid species did not show significant differences between sexes and co-varied with host length. All age classes were infected; maximum prevalence values were reached before maximum mean intensity values in the 1-yr age class. A seasonal pattern of prevalence and mean intensity of the 2 parasite species with autumn mean intensity values differing significantly from those of the other seasons was evident only in Lake Gutiérrez.
authors.affiliation: Laboratorio de Parasitologla, Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, Avda. Quintral 1250, 8400 San Carlos de Bariloche, Río Negro, Argentina.
authors.forename: Verónica
authors.initials: V
authors.lastname: Flores
authors.forename: Semenas
authors.initials: S
authors.lastname: Liliana
mesh_terms: D000367:Age Factors; D000818:Animals; D001118:Argentina / Q000453:epidemiology; D001921:Brain / Q000469:parasitology; D005260:Female; D005393:Fish Diseases / Q000453:epidemiology* / Q000469:parasitology; D005618:Fresh Water; D006358:Hot Temperature; D008297:Male; D036441:Osmeriformes / Q000469:parasitology*; D015995:Prevalence; D012621:Seasons; D014200:Trematoda / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D014201:Trematode Infections / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*