About the fauna of mayflies (Insecta, Ephemeroptera) Nakhchivan Autonomous Republic

In the hydro fauna of Nakhchivan Autonomous Republic 22 species of mayflies were found in larval stage, belonging to 5 superfamilies, 9 families and 17 genus. Comparative analysis of species composition, distribution pattern, relationship with ecological factors and seasonal dynamics of mayfly fauna of two river systems formed on the territory of Shahbuz district in similar soil and climatic conditions was carried out. It was found that there is a direct relationship between the species richness of larvae and the diversity of biotopes (as well as microbiotopes) of mountain rivers. The dominant species (P>50%) for the benthic fauna of rivers and tributaries flowing in Shakhbuz district are Potamanthus luteus, Siphlonurus lacustris, Baetis rhodani, Cloeon dipterum, Heptagenia ulfurea, Serratella ignita and Caenis macrura. During the study period, the average biomass of nymphs for the Nakhchivanchai River and its basin was 0.354 g/m2 (abundance - 105 individuals/m2), and for the Kyukuchai River - 0.065 g/m2 (27 individuals/m2). In the rivers of the Autonomous Republic, intensive development of nymphs usually occurs in spring and summer.