Genus Baetis Leach, 1815

Diagnosis.

The main diagnostic morphological characteristics of the genus pertain to nymphs and include the cylindrical body, two pairs of wing pads, absence of setae between prostheca and mola of both mandibles, simple stout prostheca on both mandibles, presence of femoral villopore, robust tarsal claws with a single row of denticles, gills consisting of a single lamella on abdominal segments I–VII, unmodified paraproct and three caudal filaments (Bauernfeind and Soldán 2012). The present study is focused only on Baetis s.s. and the following descriptions include only nymphs.