Infection pattern 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 Andea

FLORES, V. , SEMENAS, L.

JOURNAL OF PARASITOLOGY

American Society of Parasitologist

Lugar: Winston Salem; Año: 2002 vol. 86 p. 1135 - 1139

0022-3395

   In Patagonian Andean region two species of diplostomatids parasitise brain 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 with non-parametric tests. The two species co-occurred in the majority of sampled lakes with high values of prevalence and mean intensity. In lakes Gutiérrez and 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 and maximum prevalence values were reached in the first age classes and previous to maximum mean intensity values. A seasonal pattern of prevalence and mean intensity of the two parasite species with autumn mean intensity values differing significantly from the other seasons was only evident in lake Gutiérrez.