Growing Up in the Cold: Notes about Winter Diet of Perla grandis Rambur, 1842 (Plecoptera, Perlidae) in a Glacial Stream (Aosta Valley - NW Italy)

Aquatic insects constitute the richest and most diverse component of river communities, but while taxonomic knowledge has increased enormously, many aspects of their ecology remain unknown. Studying aquatic insects' trophic ecology can be useful in order to better understand not only their diet, but also ecosystem functioning and biogeochemical processes. Furthermore, looking at the apical predators present in a specific environment is of utmost importance, especially in those fishless habitats where aquatic insects, such as stonefly nymphs, are at the apex of the trophic web. Herein, we report our findings regarding diet selection implemented by the Plecoptera Systellognatha Perla grandis in a glacial alpine lotic system. Obtained results suggest that: i) fine organic matter (FPOM) can be frequently found in examined gut contents, ii) some prey are actively selected and iii) age-related prey selection shift can be observed.