Terrestrial isopods from warm shores neighboring the thermal waters from western Romania remain active in the winter. This phenomenon is registered in 35 habitats, affecting 12 species (Hyloniscus transsilvanicus, H. riparius, Haplophthalmus danicus, Trichoniscus sp., Androniscus roseus, Cylisticus convexus, Protracheoniscus politus, Trachelipus nodulosus, T. rathkii, Porcellio dilatatus, Armadillidium vulgare, A. versicolor), the most common being T. nodulosus. Females with a marsupium were observed in the cold season in the case of some small-sized species that are present in the immediate vicinity of the shores of thermal waters (A. roseus, H. riparius and H. transsilvanicus). The high temperatures of the thermal waters warm the surrounding terrestrial environment, affecting the life cycle of the terrestrial isopods
