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Fisheries Science of Ukraine, 2026; 3(77): 4-22
DOI: https://doi.org/10.61976/fsu2026.03.004
UDC 597:615.84:591.1

Received: 30.07.2026
Received in revised form: 17.08.2026
Published: 30.09.2026

Electric shock injuries in freshwater fish: Characteristics of morphological changes in the body

М. Horila, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0002-1385-6751, Dnipro State Agrarian and Economic University, Dnipro
R. Novitskyi, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0001-9373-5759, Dnipro State Agrarian and Economic University, Dnipro
D. Kobyakov, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0002-7086-8337, Dnipro State Agrarian and Economic University, Dnipro

Purpose. To systematise and describe the ichthyopathological signs of damage to freshwater fish resulting from the lethal effects of an electric current.

Methodology. The material for the study were 52 individuals of 11 fish species (4 families) seized between 2010 and 2025 during nature conservation raids on the Kamianske and Dniprovske reservoirs from citizens suspected of using homemade electrofishing devices. Standard ichthyological methods were applied; morphological and anatomical analyses were carried out on fresh fish, which were subjected to visual inspection to note the presence of damage to the head, body, fins, and oral cavity as well as any breaches in the integrity of the scale cover. The presence of haemorrhages in the fish’s eyes, under the skin, in the genital pores and in the fin rays was recorded. During the anatomical dissection, the normal and pathological conditions of the internal organs were recorded, and internal haemorrhages, tissue and organ destruction, and organ damage were noted. General scientific research methods were also employed including analysis, synthesis, generalisation, induction, deduction, and explanation.

Findings. The morphological changes included damage to the skin, haemorrhages in the lateral line organs, eyes, muscles and internal organs as well as alterations in the structure of the fish’s tissues. The nervous system, muscle tissue and the cardiovascular system were the most sensitive to the effects of an electric field. The least “sensitive” organs were the gallbladder and the spleen (except in catfish), which were virtually unaffected.Taxonomic differences were noted in the nature of the lesions observed in fish from different families. A combination of characteristics such as the very good condition of the dead fish, with no damage to the mouth, scales or fin rays, and no injuries, scratches or loss of mucous coating, together with the presence of haemorrhages in the eyes, under the skin, in the gill slits, fin rays, abdominal cavity, tissues and internal organs (liver, heart, brain, gonads), organ destruction and “coagulation” of blood vessels may, with a high degree of certainty, indicate precisely that the fish have suffered an electric shock.

Originality. At present, there is no unified methodological and technical framework in Ukraine for diagnosing injuries to fish caused by the use of homemade electrofishing devices. The lack of an evidence base regarding this fishing method makes it difficult to classify offences and hold offenders to account. The fact that a poacher has used an electrofishing device for illegal fishing can be proven by the presence of specific morphological changes in the bodies of aquatic organisms resulting from electric shock.

Practical Value. The described and systematised ichthyopathological signs of damage to fish can be used by nature conservation authorities to make a clear and unequivocal diagnosis of the lethal effects of electric current on aquatic organisms.

Keywords: aquatic bioresources, fish, electric current, electrofishing, electric fishing rod, illegal fishing, morphological characteristics, electric injury, damage, lethal effect.

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