Fauna of the Cladoceran and Copepods Crustaceans (Crustacea: Cladocera, Copepoda) of Dood Tsagaan Lake (Darhad Basin, Mongolia) in Modern Times

Abstract

The paper presents the results of the study the qualitative and quantitative composition of the planktonic Crustacea of Dood Tsagaan Lake (northwestern Mongolia) (Cladocera, Diaptomidae, Cyclopidae) in modern times. Comparative analysis of the species composition of crustaceans according to new data and data obtained in the last century (1962–1963) showed that during our studies the composition of crustaceans was increased by five species of Cladocera and by three species of Copepoda, 2 species of them are from the order Cyclopoida and one from the order Calanoida. Ultrastructural studies of the main morphological parts of the copepods crustaceans Mixodiaptomus incrassatus (Sars, 1903), Acanthodiaptomus paulseni (Sars, 1903) and Cyclops glacialis Flossner, 2001 were carried out for the first time using a scanning electron microscope (SEM). Detailed study of morphometric and morphological characters including the use of SEM showed that C. glacialis inhabiting Dood Tsagaan Lake is identical to the species described in lakes (Turgun Kharhiraa Uvs aimag and Nogoon nuur) in northwestern Mongolia. The biomass of M. incrassatus, an important food object for whitefish and other fish species, was found to reach 1100 mg/m3 in the modern period.