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Ribogospod. nauka Ukr., 2025; 4(74): 272-285
DOI: https://doi.org/10.61976/fsu2025.04.272
UDC 619:611.37:611-073.7:636.7

Morphofunctional state of the midcerebral roof and photoreceptor block of the Prussian carp (Carassius auratus gibelio Bloch, 1782) under conditions of human impact on the water body

O. Koziy, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0002-0064-4637, Kherson Agrarian and Economic University, Kherson

Purpose. To assess the visual block of Prussian carp based on the analysis of histological parameters of its components, to establish the level of impact of human impact on the fish health, to determine the degree of damage and the possibility of restoring structures. To determine the prospects for using histological monitoring data in morphological and ecological practice.

Methodology. The primary materials were obtained in the autumn of 2025 in the Southern Bug River, Mykolaiv city and in a reservoir within the village of Zherebkove, Podilskyi district, Odesa region. The histological samples were processed in the laboratory of Histology, Cytology and Embryology of the Petro Mohyla Black Sea National University using a technique specially designed for the histological diagnosis of tissues of aquatic organisms of animal origin.

Findings. Microanatomical studies of the midbrain roof and the photoreceptor block of the Prussian carp have shown significant changes occurring under anthropogenic stress in layer 5, layer 4 of the midbrain roof (MВR), and both nuclear and reticular layers of the retina. Transformations within layer 4 of the MВR are manifested in the death of a portion of neurons. Cellular detritus is utilized by microglia and subsequently replaced by scars of loose, irregular connective tissue. Nerve fibers of layer 4 of the roof of the midbrainlose their characteristic orientation. The inflammatory reaction in the tissue of layer 5 of the roof of the midbrainis manifested in the form of proliferation of the vascular network with vessels surrounded by hyaline interlayers. Connections between the roof of the midbrainareas and the corresponding organs are blocked due to compression of nerve fibers, which leads to retinal atrophy. A characteristic feature of the pathology is the loosening of the pigment layer and the loss of synaptic connections between individual neuronal groups. Slowing down the transformation of the vascular network in layer 5 of the roof of the midbraincan be achieved due to the trophic properties of oligodendrocytes. The number of neuroblasts, which decreases with age, is not able to provide regeneration of the affected areas of the roof of the midbrain. Under conditions of chemical stress, changes in the roof of the midbrainand the photoreceptor unit are progressive and lead to vision loss.

Originality. New and supplemented existing data on the reaction of the histological structure of the MВR and the retina of the Prussian carp under conditions of human impact on the habitat are presented. For the first time, a detailed histological analysis of the structure of organs under the action of a toxicant of unknown origin is carried out. Based on a comparative analysis, information on changes in the structures of the visual analyser of fish, which demonstrates the destruction of the adaptive capabilities of the species, is updated and supplemented.

Practical Value. The factual information is of certain value in histological studies as well as in ecological practice in connection with the existing problem of reducing the vital potential of fish under conditions of human impact on water bodies. The use of the obtained results is possible in the process of developing corrective measures for the purpose of environmental protection.

Keywords: Prussian carp, technogenic load, roof of the midbrain, retina, neurons, nerve fibers, adaptation.

REFERENCES

  1. Souza, J. P. (2017). Toxicological effects of graphene oxide on adult zebrafish (Danio rerio). Aquatic Toxicology, 186, 11-18. https://doi.org/10.1016/j.aquatox.2017.02.017.
  2. Gerhard, G. S. (2003). Comparative aspects of zebrafish (Danio rerio) as a model for aging research. Experimental Gerontology, 38, 1333-1341. https://doi.org/10.1016/j.exger.2003.10.022.
  3. Subaramaniyam, U., & Allimuthu, R. (2023). Effects of microplastics, pesticides and nano-materials on fish health, oxidative stress and antioxidant defense mechanism. Frontiers in Physiology, 14, 17-66. https://doi.org/10.3389/fphys.2023.1217666.
  4. Grosell, M., & Pasparakis, C. (2021). Physiological responses of fish to oil spills. Annual Review of Marine Science, 13, 137-160. https://doi.org/10.1146/annurevmarine040120-094802
  5. Baraboy, V. P. (2006). Stress: nature, biological role, mechanisms, consequences. Kyiv: Phytocenter, 42-44.
  6. Koziy, M. S. (2014). Microanatomical organization of organs and tissues of fish in natural and modified fish species. Extended abstract of Doctor’s thesis. Kiev.
  7. Camargo, J., & Alonso, Á. (2006). Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment. Environment International, 32, 6, 831-849. https://doi.org/10.1016/j.envint.2006.05.002 
  8. Dane, H., & Sisman, T. (2017). A histopathological study on the fresh water fish species chub (Squalius cephalus) in the Karasu River, Turkey. Turkish Journal of Zoology, 41, 1, 1-11. https://doi.org/10.3906/zoo-1509-21 
  9. Pickering, A. D. (1981). Stress and Fish. New York: Academic Press.
  10. Si-Qi, Zhang, & Ping, Li. (2021). Hepatotoxicity in carp (Cyprinus carpio) exposed to environmental levels of norfloxacin (NOR): Some latest evidences from transcriptomics analysis, biochemical parameters and histopathological changes. Сhemosphere, 131-210. https://doi.org/ 10.1016/j.chemosphere.2021.131210.
  11. Rohani, M. F. (2023.). Pesticides toxicity in fish: Histopathological and hematobiochemical aspects: a review. Emerging Contaminants, 9, 3, 100-234. https://doi.org/10.1016/j.emcon.2023.100234.
  12. Dekhtyaryov, P. A. (2001) Physiology of fishes. Kyiv: Higher School, 12-17.
  13. Hong, L., & Dan, L. (2023). Study on metabolic changes of Crucian carp induced by phoxim based on 1H-NMR metabolomics. Food and Machinery, 39, 5, 4-30. https://doi.org/10.13652/j.spjx.1003.5788.2023.60010.
  14. Jia, R., & Du, J. (2020). Chronic exposure of hydrogen peroxide alters redox state, apoptosis and endoplasmic reticulum stress in common carp (Cyprinus carpio). Aquatic Toxicology,229, 105-657. https://doi.org/ 10.1016/j.aquatox.2020.105657.
  15. Yu, Y., & Wang, Z. (2024). Occurrence, bioaccumulation, fate, and risk assessment of emerging pollutants in aquatic environments: A review. Science of the Total Environment, 923, 171-388. https://doi.org/10.1016/j. scitotenv.2024.171388.
  16. Koziy, M. S. (2011). Histomorphological features of the ichthyofauna of Southern Ukraine. Kherson: Oldies plus.
  17. Koziy, M. S. (2009). Assessment of the current state of histological technology and ways to improve the study of ichthyofauna. Kherson: Oldi-plus.
  18. Chavan, V. R., & Muley, D. V. (2014). Effect of heavy metals on liver and gill of fish Cirrhinus mrigala. International Journal of Current Microbiology and Applied Sciences, 3, 5, 277-288.
  19. Huang, T., & Zhao, Y., (2022). Endocrine disruption by azole fungicides in fish: A review of the evidence. Science of the Total Environment, 822, 153-412. https://doi.org/10.1016/j.scitotenv.2022.153412.
  20. delo.ua. Retrieved from: https://delo.ua/news/voda-rozovogo-cveta-v-odesskoi-oblasti-massovo-pogibla-ryba-45375.
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