Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 29-30. (Budapest, 1997)

M. nivalis is a Mustelid with a circumboreal distribution and it shows a rather complicated systematics (Beaucournu and Gruhlich 1968, Kratochvil 1977, Von Frank 1985). The wide away of phylogenetic studies, which have been already carried out (based on morphological, biological, ethological, physiological and genetic features; Heidt 1979, Nei 1972, Simonsen 1982, Brinck et al. 1983), contrast with the limited parasitological knowledge available at present. In the area of Helminthology, the studies known refer, in general, to very small samples, originating from Central or Eastern Europe (Prokopic 1958, Soltys 1962, Kontrimavichus 1963 and 1985, Mituch et al. 1992). The only study based on a larger sample (80 specimens) is that carried out by Prokopic (1965) in Czechoslovakia. Other studies had an ecological interest referring to some helminths, principally to Skrjabingylus nasicola (Leuckart, 1842) and Trichinella spiralis (Owen, 1835) (Kozlov and Kontrimavichus 1961, Fahmy 1964, Hansson 1968, Lancaster et al. 1973, King 1977, Lewis 1978, Fameree et al. 1981, Aymerich et al. 1983, Gerard and Barrat 1986, Vlcek 1991). On the Iberian Peninsula there was only a preliminary study based on 10 specimens from the Montseny Massif (Miquel et al. 1992). Our study provides the first important data on the helminth fauna of M. nivalis in Western Europe. Furthermore, when one compares the faunistic results obtained for Iberia with those data already known for this Mustelid in the rest of Europe, the peninsular effect on the composition of the Iberian helminth fauna can be noticed. From an ecological point of view, the results obtained have provided unprecedented data in Europe, about the influence of the sex and the geographical location on the helminth fauna of a representative of Mustela genus. It is obvious that the current work is a valuable help to elucidate the structure of the peninsular helminth faunas of the Mustela species. This objective seems rather easy if we take into account the specificity (oligoxenia) of many parasite species. This would imply a clear similarity of those parasitic faunas (Motje 1995). MATERIAL AND METHODS 168 weasels were analysed (102 males and 30 females). The sex of the 36 remaining specimens was not determined. They came from several enclaves of 29 Spanish provinces. Hosts were classified according to the geographical location of capture sites into 5 Spanish areas, according to the 38°N, 40°N and 42°N parallels of latitude and the 4° meridian (see Fig. 1). The number of individuals analysed in the areas was: NW=37; NE=24; CN=50 and CS=29. Two specimens from the more southern region (S) were added to the CS group. The individuals coming from the Montseny Massif (MON=28) were separated from the CN population, to which they geographically belong, due to the peculiar ecological conditions of the area. This area has been considered as an isolated continental ecosystem (Miquel et al. 1992, 1994 a and b). Captured hosts were kept frozen or in 70% etanol or 10% formaldehyde until the helminthological analysis. The isolated helminths were processed according to helminthological methodology, and were microscopically determined, following the specialised literature for each species (see Miquel et al. 1994a). The terminology, the quantitative parameters and the statistic treatment are detailed in Pence and Eason (1980), Margolis et al. (1982) and Combes (1987). Trichinella sp. were only treated in prevalence terms. Data referring to Skrjabingylus nasicola are based only on the eight examined weasel skulls. The worm burden of Filaroides martis refers to parasitic nodules.