Experimental assessment of the chronic effect of increased mineralization and temperature on somatic indices, biochemical blood parameters and survival of perch Perca fluviatilis juveniles
P. B. Mikheev1,2, M. V. Mukhina1, N. V. Kostitsyna1, M. A. Baklanov1, A. Yu. Puzik1
1Perm State National Research University, Perm, Russia
2Khabarovsk NIRO, Khabarovsk, Russia
Keywords: pollution, salinization of fresh waters, climate change, temperature, ecological tolerance of fish, survival, multiple stressors, blood biochemistry
Abstract
The results of the evaluation of the effect of experimentally dosed salinization and salinization with a simultaneous moderate increase in temperature on somatic indices, biochemical blood parameters and survival of perch Perca fluviatilis fingerlings are presented. The limit of salinity tolerance for perch fingerlings used in the experiment turned out to be a mineralization value of 8 g/l. An increase in temperature led to a decrease in the tolerance limit of perch fingerlings during salinization to 5.3 g/l. In conditions of elevated temperature and mineralization, maximum mortality was noted, the lowest values of the fatness coefficient and the hepatosomatic index of fish, indicating the depletion of experimental individuals, which was determined by the revealed violations of water homeostasis. An increase in energy costs with an increase in temperature is consistent with the data of an increase in the load on the excretory system of fish due to an increase in the permeability of fish tissues, which leads to a decrease in the content of basic inorganic ions in blood plasma. At background temperature, chronic exposure to increased mineralization also leads to depletion of the metabolic reserves of the fish body and the predominance of catabolic processes, which is confirmed by the low content of total protein and protein metabolism metabolites in blood plasma.
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