Component population study of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno (Argentina)

RAUQUE, C.; G. VIOZZI; L. SEMENAS

FOLIA PARASITOLOGICA

Institute of Parasitology, Academy of Sciences of Csech Republic

Lugar: Éeske Budijovice; Año: 2003 vol. 50 p. 72 - 78

0015-5683

Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. A. tumescens showed low host specificity, successfully parasitising six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei (Steindachner), Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and G. maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, being P. trucha the major one. Different regulatory and non regulatory mechanisms are suggested.