Bottom meiofauna of highly mineralised rivers in the Eltonsky Nature Park (Russia)

Abstract

As established by numerous research the community of bottom meiofauna (meiobenthos) plays an important role in the diversity, quantitative characteristics and trophic relationships of the hydrofauna, as well as in the general flow of matter and energy of both marine and freshwater ecosystems. At the same time, to date it remains poorly studied in many types of water bodies, for example, in highly mineralised rivers. In 2009–2017 a study of meiobenthos was conducted for the first time in the saline tributaries of the hypergalin Lake Elton, located in the protected area of the Eltonsky Nature Park (Volgograd Region, Russia). This current paper provides information on the overall taxonomic composition of the community in rivers, as well as an annotated checklist of identified species. The data on the structure and abundance of the species populations, their occurrence, ecology, global and local distribution are given in the checklist along with taxonomic and other comments. In total 73 taxa of 12 systematic groups of hydrobionts have been recorded. There are 38 representatives identified to species level. Among them, there are three species (nematodes Diplolaimelloides delyi, Ethmolaimus multipapillatus, and Monhystrella parvella) that had not been recorded previously from Russia and five species (nematodes Allodiplogaster media, Calodorylaimus salinus, Daptonema salinae, Mesodorylaimus rivalis, and Oncholaimus rivalis) which have been collected here for the first time and described as new to science. The presence of rare and new species shows a certain uniqueness of the ecosystems of the tributaries of Lake Elton and indicates the need for their further study and conservation.

Keywords

• distribution
• meiobenthos
• population abundance
• population structure
• saline rivers
• taxonomic composition