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. 2025 Mar 29;13(4):261.
doi: 10.3390/toxics13040261.

Changes in the Erythrogram Parameters and in the Erythrocyte Sizes of Adult Pelophylax ridibundus (Pallas 1771) (Anura: Ranidae) Inhabiting the Sedimentation Lake of Brikel Thermal Power Plant in Southern Bulgaria

Zhivko Zhelev  1 , Tihomir Vachev  2 , Danail Minchev  1
Affiliations

Changes in the Erythrogram Parameters and in the Erythrocyte Sizes of Adult Pelophylax ridibundus (Pallas 1771) (Anura: Ranidae) Inhabiting the Sedimentation Lake of Brikel Thermal Power Plant in Southern Bulgaria

Zhivko Zhelev et al. Toxics. .

Abstract

Analyses of the hematological statuses of animals inhabiting areas of anthropogenic pollution may provide valuable insights into the extent of disturbance of their living conditions and the mechanisms of adaptation to various environmental stressors. The current work compares the erythrogram and erythrocyte-metric parameters of marsh frogs (Pelophylax ridibundus) inhabiting the polluted sedimentation lake of Brikel TPP in southern Bulgaria to those in frogs inhabiting a relatively clean habitat (reference population). The study includes a total of 120 individuals (30 females and 30 males from each site). For all of them, total erythrocyte count, hemoglobin concentration, hematocrit, MCV, MCH, and MCHC were evaluated via standard laboratory techniques. All erythrocyte metrics were determined microscopically in two blood smears from each animal. Our study reveals alterations in the erythrogram parameters and the erythrocyte sizes in marsh frogs living in conditions of chronic pollution with industrial wastewater compared to the animals from the reference site. The mean values for all erythrocyte morphology parameters are significantly lower in both female and male individuals inhabiting the polluted area compared to those originating from the reference one. Conversely, three erythrogram parameters-erythrocyte count, hemoglobin, and hematocrit-appeared significantly higher in females and males from the polluted site. The observed changes in the erythrogram parameters and erythrocyte sizes result from the deteriorated water quality of the sedimentation lake.

Keywords: ecotoxicology; environmental pollution; erythrocyte-metric parameters; erythrogram; marsh frogs; red blood cells.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
(a) General view of the sedimentation lake; (b) TPP AES “Galabovo” and TPP “Brikel”; (c,d) heaps of industrial ash; (e) a temporary body of water within the area of the sedimentation lake; (f) a male individual of Pelophylax ridibundus. Places where frogs were captured (arrows, e).
Figure 2
Figure 2
(a) A diagram of the correlations of erythrogram and erythrocyte-metric parameters in the Pelophylax ridibundus individuals from the investigated sites with the first two main axes. The distinguishing force of the parameter is indicated by the arrow length; a large importance is shown by the long arrow and it is strongly correlated with the ordination axes. (b) A scree plot of the proportion of variance explained by each principal component.
Figure 3
Figure 3
Photomicrographs of erythrocytes of Pelophylax ridibundus individuals from the polluted site, (a,b) the sedimentation lake of Brikel TPP, and the reference site, (c,d) Vacha River in southern Bulgaria. Scale lines = 10 μm.
See this image and copyright information in PMC

References

    1. Saaristo M., Brodin T., Balshine S., Bertram G.M., Brooks B.W., Ehlman S.M., McCallum E.S., Sih A., Sundin J., Wong B.M., et al. Direct and indirect effects of chemical contaminants on the behaviour, ecology and evolution of wildlife. Proc. R. Soc. B. 2018;285:20181297. doi: 10.1098/rspb.2018.1297. - DOI - PMC - PubMed
    1. Erişmiş U.C. Evaluation of DNA damage by Comet Assay in Populations of Endemic Beyşehir Frog Pelophylax caralitanus (Arıkan, 1988) Ege J. Fish. Aquat. Sci. 2019;36:109–114. doi: 10.12714/egejfas.2019.36.2.02. - DOI
    1. Franco-Belussi L., Provete D.B., Leão T.R.F., Siquiera M.S., Valverde B.S.L., Martins B.O., de Oliveira C., Fernandes C.E. Hematological parameters of a Neotropical wild frog population, with a phylogenetic perspective on blood cell composition in Anura. Curr. Zool. 2022;68:361–369. doi: 10.1093/cz/zoab059. - DOI - PMC - PubMed
    1. Vitt L.J., Caldwell J.P. Herpetology: An Introductory Biology of Amphibians and Reptiles. 4th ed. Elsevier Science; San Diego, CA, USA: 2013. p. 53. - DOI
    1. Van Meter R.J., Glinski D.A., Hong T., Cyterski M., Henderson W.M., Purucker S.T. Estimating terrestrial amphibian pesticide body burden through dermal exposure. Environ. Pollut. 2014;193:262–268. doi: 10.1016/j.envpol.2014.07.003. - DOI - PubMed

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