Feeding on the roof of the world: the first gut content analysis of very high altitude Plecoptera

The biology of Plecoptera from high altitude Himalayan freshwaters is almost unknown. Very few and sporadic studies have been devoted to these insects, and exclusively with a taxonomic approach. We provide information on the feeding of Capnia nymphs from three lakes localized above 4,800 m a.s.l. (NE Nepal). Nymphs from these high altitude lakes feed mainly on fine detritus, acting as collector- gatherers, with the accidental ingestion of mineral matter, mostly in larger specimens. It is likely that the harsh environmental conditions in our study area create an environment unfavorable to both the allochthonous input of coarse particulate organic matter (such as terrestrial leaves) and the autochthonous input related to aquatic primary productivity, so that these nymphs feed on small organic particles that originates mainly from the catchment.