Communities of macroparasites of freshwater fishes from Patagonian Andean lakes of Argentina

SEMENAS, L.; RAUQUE, C.; FLORES V.; VIOZZI G. ; BRUGNI, N.; FERNANDEZ, M.V. ; VEGA, R.

Melbourne

Congreso; XII International Congress of Parasitology; 2010

In Argentina no studies of component community of macroparasites of freshwater fish have been performed. The aim of this study was to describe and compare the macroparasite component communities between 3 oligotrophic lakes with differences in areas, presence of shoreline vegetation and/or fish assemblages, hypothesizing that the macroparasite richness is different in relation to the combination of these characteristics. The smallest lake has an area of 0.01 km2 and the medium 16.4 km2, both with vegetated shoreline. The biggest one has an area of 557 km2 without vegetation in the shoreline. Samples of fishes were collected seasonally with nets in different sites in each lake. In total, the following native species were captured: 1,150 Galaxias maculatus, 97 Galaxias platei, 28 Diplomystes viedmensis, 27 Odontesthes hatcheri and 306 Percichthys trucha. The exotic species comprised: 213 Oncorhynchus mykiss, 72 Salvelinus fontinalis and 18 Salmo trutta. All fish organs were examined, and macroparasites were identified to calculate richness. The most common taxa were digeneans, and nematodes. Richness was 18 in the smallest lake with 2 native and 1 exotic fish species, 31 in the medium lake and 27 in the largest both with the same assemblage of fish species, 5 native and 3 exotic. The lowest macroparasites species richness was found in the smallest lake with the lower fish assemblage. When the medium and large lakes are analyzed, macroparasite richness increased at least 70%. Considering the same fish assemblage is present in both lakes, differences in richness can be attributed to the presence of refugees associated with shoreline vegetation.