Distribution and biology of mayflies (Ephemeroptera) of the Czech Republic: present status and perspectives

The checklist of mayflies of the Czech Republic now comprises 107 species (30 genera, 16 families), 87 spp. found until 1970 (first research period) and 99 after 1970 (second research period). The distribution of these species in principal river basins (Elbe: 95 spp., Danube: 79 spp. and Oder: 55 spp.), their frequency, abundance and spatial distribution (highest richness in the colline zone: 93 spp.) are summarised. Main species traits (current preference, feeding and locomotion types and life cycle) are presented in tables. Saprobiological characteristics, substantially modified or newly suggested in at least 36 spp., are defined according to the Czech Standard. Four species are classified extinct, 7 critically endangered, 7 endangered, 16 vulnerable and 14 near threatened. Long-term changes caused mainly by morphological degradation of potamal watercourses (extinction and area diminishing, re-occurrence at some sites after decades of very scarce frequency or quantitative changes) are discussed.