Distribution and ecology of red algae in Italian rivers

Freshwater red algae are rarely documented in Italy, although their presence is quite common in European watercourses. The few data available about this algal group are reported in broader studies concerning algal flora of Italian rivers. This paper is aimed to broaden the knowledge on red algae in Italian running waters, by providing new findings on this algal group occurrence in Italy. Samples of Lemanea fluviatilis, Batrachospermum gelatinosum, Bangia atropurpurea, Compsopogon caeruleus, Hildenbrandia rivularis and samples at sporophytic Chantransia stage, were collected from 29 sites along 16 watercourses of central Italy. For each species, we provided a review on the European distribution, giving particular attention to its diffusion in Italy. We also contributed to better define the autoecology of these species, by increasing data on their ecology and defining quantitatively their ecological responses to main environmental factors. Through this study we provided the first record of a spontaneous population of the sub-tropical C. caeruleus in Italy.