Известия высших учебных заведений. Поволжский регион: Естественные науки (Jun 2020)
THE CHANGE IN THE TROPHIC AND ECOLOGICAL STRUCTURES OF CILIOFAUNA IN THE LOWER REACH OF THE LYUTOGA RIVER DURING THE APPEARANCE OF THE DEAD PACIFIC SALMON IN IT
Abstract
Background. For the first time, on the example of the Lyutoga river (the southern part of Sakhalin island), the features of the ciliary community formed in areas where Pacific salmon die have been studied. The aim of the work is to study changes in the trophic and ecological structure of the community of infusoria of mountain-plain watercourses during the period when the dead pink salmon got into it. Materials and methods. The material was collected in 2012 and 2018 in the lower reaches of the Lyutoga river. In places where salmon producers died (in shoalshallows), samples were taken into glass non-specialized containers by scooping water together with a layer of soil and the remains (parts of the skeleton) of salmon. Results. During this period 36 species of infusoria belonging to the classes Heterotrichea, Oligomenophorea and Spirotricheawere found. In the samples Spirostomum ambigium, Paramecium caudatum, Urocentrum turbo, Aspidiscaturrita, Uronemamarinum, Stentor roeselii, Steiniaplatystoma, Frontonia leucas and Chilodonellauncinatus, which belong to the trophic groups of bacteriophages and euryphages, as well as to the periphyton-benthic ecological group were dominated. There was an increase of the saprobityinto the watercourse in the study period. Conclusions. The trophic and ecological structures of the ciliary community were significantly simplified. The dominant species during this period can be considered specific to these environmental conditions. In river systems in the South of Sakhalin, it is possible to allocate an adaptive complex that develops on the death of Pacific salmon. The dominance of 9 of the above-mentioned species in the ecosystems of mountain-plain watercourses in the southern part of Sakhalin island may indicate the presence of increased organic pollution in them. In addition to fluctuations in abiotic factors, the change in the ciliate community in these watercourses is significantly affected by the seasonal influx of natural pollutants into them.
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