Functional indicators of poikilothermic aquatic species from natural and artificial water biocenoses

For assessment of sustainability of natural biocenoses and the physiological and immunological state of hydrobionts in aquaculture, it is necessary to know functional parameters of circulating liquids in hydrobionts of different taxonomic groups. The purpose of this study was to analyze the limits of the main indicators of homeostasis in aquatic animals and fish from natural water bodies, i.e. crayfish ( Astacus astacus and Pontastacus leptodactylus ), fish (carp Cyprinus caprio L., tench Tinca tinca L. and catfish Silurus glanis L.), and amphibians (frogs Rana temporaria and Xenopus laevis ). Here, here is the first report on hematologic, cytochemical, biochemical indicators for these species which inhabits natural water bodies or are artificially grown in the conditions of Moscow and Pskov provinces and Chuvashiya region. Hematological investigations included differential count of blood cells of fishes and amphibians in smears stained by the Pappengeim technique; hemolymph of river crayfish was examined in Goryaev chamber. Immunological parameters were evaluated by cytochemical method as an average cytochemical coefficient (CCC) of lysosomal cationic protein in fish blood neutrophils and crayfish haemocytes in the reaction with Bromphenol blue. Biochemical parameters were assessed in blood serum using a biochemical analyzer Chem Well (Awarenes Technology, Inc., USA). The reference constants of homeostasis we found are as follows: the total number of cells in crayfish hemolymph of 700 to 800 per 1 µl; the number of red blood cells in fish of 1-2 million/µl, blood leukocytes in fish of 50-150 thousand per 1 µl. Interspecific differences in haemocyte patterns between Astacus astacus and Pontastacus leptodactylus were not revealed. Biochemical differences were as follows: glucose concentration in the Astacus astacus hemolymph was 64 % higher compared to that in Pontastacus leptodactylus whereas the alkaline phosphatase activity was almost 71 % lower. Agranular and semi-agranular haemocytes, along with juvenile forms that we called transparent cells, serve as phagocytes in crayfish. In healthy crayfish, phagocytic activity of these cells, as estimated by the average cytochemical coefficient of the lysosomal cationic protein level, was approximately the same and ranged from 1.5 to 2.0. In fish, we found gender and species-related differences of homeostatic constants. The presence of promyelocytes, the blast forms of leukocytes, in Tinca tinca was indicative of more intensive leukopoiesis. The percentage of neutrophils was higher in male Tinca tinca due to 2- to 3-fold number of band neutrophils compared to other groups. The level of non-enzyme cationic protein in the lysosomes of neutrophils of female carp, tench and catfish were higher compared to male individuals. The activity of aspartate aminotransferase (AST) in male tench and catfish was almost 3 times higher than that in carp. The carbohydrate metabolism in carp and catfish, in terms of lactate concentration, was more than 3 times higher compared to tench. Among the studied amphibians, we observed interspecific and gender differences. The proportion of segmented neutrophils in Rana temporaria was more than 4 times higher than that of Xenopus laevis. Gender variations in the number of segmented cells were as follows: the cell number in male Rana temporaria and Xenopus laevis were 27 and 33 % lower than that of females. The blood lymphocyte counts in Rana temporaria were significantly lower than that in Xenopus laevis. We found gender differences of Rana temporaria on biochemical parameters. As compared to the males, the female Rana temporaria showed higher activity of ALT and AST (by 6 and 19 %, respectively), creatine kinase (by 29 %), and alkaline phosphatase (by 60 %). The total blood protein content in amphibians was 2-3 %, blood glucose averaged 1-4 mmol/l, triglycerides varied from 0 to 400 mg%. It is proposed to use parameters of aquatic organisms’ homeostasis for ecological monitoring of natural and artificial water biocenoses.