Entomologica Romanica Vol. 18 / 2013


Entomologica romanica 18: 5-10, 2013 ISSN 1224-2594 / article no.: ER18201301 Data upon the terrestrial isopod fauna from the western slope of Oas Mountains, Romania Sára Ferenți, Éva-Hajnalka Sas-Kovács, István Sas-Kovács & Severus-Daniel Covaciu-Marcov Summary: In the western slope of Oas Mountains we identified 16 terrestrial isopod species: Ligidium germanicum, L. hypnorum, Hyloniscus riparius, H. transsilvanicus, Trichoniscus sp., Cylisticus convexus, Protracheoniscus politus, Porcellium collicola, P conspersum, Trachelipus difficilis, T. arcuatus, T. nodulosus, T. rathkii, Porcellio scaber, Armadillidum vulgare and A. versicolor The terrestrial isopod assemblages are typical for mountain regions. The species composition proved to be similar with the ones previous identified in the neighboring plain areas, suggesting their common history. The most favorable habitats were wetlands and coppices. Even in natural habitats the terrestrial isopods can use artificial shelters, fact that suggests their opportunistic behavior in the case if the habitat’s characteristics are optimal. The disturbed habitats show a relatively rich isopod fauna, they sheltering both generalists and species with narrow ecological valance. Key words: terrestrial isopods, habitats, connectivity, human impact, forest, wetlands Introduction The mountain zone of north-western Romania seems to be one of the most intense studied regions of the country in terms of terrestrial isopods (e.g. Hotea et al. 2003, Vilisics 2008, Hotea and Hotea 2008, 2009, 2010, Ferenti et al. 2012a, 2013, Ferenti and Covaciu-Marcov 2012). Although, the number of the studies about the region is high, with two exceptions (Vilisics 2008, Ferenti et al. 2013) they were realized with pitfail traps, focusing on ecological aspects. The intense research of the region seems to be righteous by the particularities of the terrestrial isopod assemblages, characterized by the presence of some mountain species at low altitudes, but also by the presence of an extremely rare, endemic species for Romania (Ferenti et al. 2013). In addition, the region is distinguished by the native terrestrial isopod assemblages linked to humid and afforested zones (Ferenti et al. 2013). These assemblages are also present at low altitudes from the vicinity of Oas Mountains, being probably present there as a consequence of the contact, which exists or had exist until recently between the forests of the two regions (Ferenti et al. 2013). Although this is plausible, till now, to our knowledge, there were not published any faunistic data about terrestrial isopod assemblages from Oas Mountains, though this kind of data exists both from low areas situated to west (Ferenti et al. 2013, Tomescu et al. 2008), and from Maramureș Depression located east of these (Vilisics 2008). Thus, this study aimed to fill the gap in knowledge about the distribution of terrestrial isopods from the western slope of Oas Mountains, north-western Romania. Also, we intended to verify if mountain species from Tur river natural protected area are indeed present in mountain natural habitats too. Materials and methods Faunistic data collection was carried out between the years 2008-2012. The limits of the investigated area are represented east by Huta Pass, south by Tur respectively Somes rivers, north and west by the country border and Tur River natural protected area. There were investigated 26 localities from the western slope of Oas and partially Ignis Mountains, from Satu-Mare and Maramureș counties (Table 1). From these localities we collected isopods from different habitats and microhabitats. From most of the localities, we collected more than one sample (a total of 55 samples), depending on the locality’s habitat richness. Thus, we investigated 11 habitat types: oak forest, beech forest, wetland, stream, coppices, semi natural wetlands, abandoned construction, road margin, orchard, canals and distilleries. Regarding the terrestrial isopods shelters, we grouped them into