ZooNotes

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https://doi.uni-plovdiv.bg/handle/store/3
ISSN: 1313-9916

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Browsing ZooNotes by Author "Georgieva, Elenka"

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    Assessing environmental stress through lysosomal membrane stability in wild and farmed mussels (Mytilus galloprovincialis Lamarck, 1819) across seasons
    (Plovdiv University Press "Paisii Hilendarski", 2025-10-30) Yancheva, Vesela; Stoyanova, Stela; Georgieva, Elenka; Antal, Laszlo; Uzochukwu, Ifeany Emmanuel; Nagy, Laszlo; Nyeste, Krisztian; Samogyi, Dora
    This study assessed lysosomal membrane stability (LMS) in hemocytes of Mytilus galloprovincialis from wild and farmed populations, using the Neutral Red Retention Time (NRRT) assay as a biomarker of environmental stress. Mussels were sampled in summer and autumn to evaluate seasonal variability, and the results were compared with our previous winter and spring data. NRRT values showed a significant reduction in both populations across seasons, indicating compromised lysosomal integrity and exposure to environmental stressors. Notably, wild mussels consistently exhibited lower NRRT values compared to farmed individuals, suggesting a higher stress burden. The underlying causes of this difference remain to be clarified.
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    Evaluation of Gill Histopathological Biomarkers in Neogobius sp. for Monitoring Freshwater Quality: A Case Study of the Veleka River, Bulgaria
    (Plovdiv University Press "Paisii Hilendarski", 2025-12-18) Stoyanova, Stela; Yancheva, Vesela; Georgieva, Elenka
    We studied the changes in the histological structure of the gills of Neogobius sp. collected from the Veleka River in Bulgaria. The results showed mainly proliferative changes in the gill structure associated with proliferation of stratified epithelium in the filament and secondary lamellae. To our knowledge, this is the first histopathological study of a fish species from the river. The observed histopathological lesions could serve as useful biomarkers for monitoring water quality and, consequently, the health of species. We emphasize the importance of such research programs that monitor the fish health in rivers, considering the dynamics of various environmental factors and pollution.
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    Histopathological Alterations in Vimba sp. Gills as Biomarkers of Freshwater Quality in the Veleka River, Bulgaria
    (Plovdiv University Press "Paisii Hilendarski", 2025-12-18) Stoyanova, Stela; Yancheva, Vesela; Georgieva, Elenka
    In the present research, we evaluated the alterations in the histological structure of Vimba sp. gills as a biomarker of freshwater quality. Fish were collected from the Veleka River. Based on the obtained results, we established the highest degree of proliferative changes. These alterations concerned mainly the covering epithelium of the secondary lamellae and proliferation of the cells in the cartilage tissue (chondrocytes). Overall, the study emphasizes the importance of biomonitoring in natural ecosystems in order to assess the health of native fish and hence the quality of surface waters.
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    How stressed are two populations of the Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) from the Black Sea (Bulgaria)? - Stress on stress biomarker responses
    (Plovdiv University Press "Paisii Hilendarski", 2025-01-15) Yancheva, Vesela; Georgieva, Elenka; Stoyanova, Stela; Todorova, Borislava; Antal, Laszlo; Nyeste, Krisztian
    This article aims to present the latest results on the stress on stress responses in farmed and wild mussels from Sozopol, Bulgaria, focusing on the autumn season of 2024. Additionally, we compare these findings with the results from the other three seasons.
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    Lysosomal membrane stability assessment in wild and farmed mussels (Mytilus galloprovincialis Lamarck, 1819) as biomarkers for environmental stress: winter and spring results
    (Plovdiv University Press "Paisii Hilendarski", 2025-05-28) Yancheva, Vesela; Stoyanova, Stela; Georgieva, Elenka; Todorova, Borislava; Antal, Laszlo; Samogyi, Dora; Uzochukwu, Ifeany Emmanuel; Nagy, Laszlo; Nyeste, Krisztian
    This study evaluated lysosomal membrane stability using the Neutral Red Retention Time (NRRT) assay in hemocytes of Mytilus galloprovincialis from wild and farmed populations, as a biomarker for environmental stress. Mussels were sampled during winter and spring to assess seasonal variability. NRRT values showed a significant reduction in both populations across both seasons, indicating compromised lysosomal integrity and exposure to environmental stressors. However, the wild mussels exhibited consistently lower NRRT values compared to the farmed individuals, suggesting a higher level of stress. The question of why is yet to be answered.
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    Physiological measurements of the Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) from the Bulgarian Black Sea as biomarkers for multi stressor environment
    (Plovdiv University Press "Paisii Hilendarski", 2024-04-05) Yancheva, Vesela; Velcheva, Iliana; Georgieva, Elenka; Stoyanova, Stela; Todorova, Borislava; Nyeste, Krisztian; Antal, Laszlo
    Wild and farmed mussels from the Bulgarian Black Sea were collected to study and compare the survival rates (stress on stress response) as a biomarker for multi-stressor environment. In sum, the survival time indicated that the farmed mussels were more tolerant to stress, even though they had a similar size and lived in similar conditions. Further research needs to be done to clarify why.
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    Stress on stress response in wild and farmed Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) from Sozopol, Black Sea (Bulgaria)
    (Plovdiv University Press "Paisii Hilendarski", 2024-06-11) Yancheva, Vesela; Velcheva, Iliana; Georgieva, Elenka; Stoyanova, Stela; Todorova, Borislava; Nyeste, Krisztian; Antal, Laszlo
    As a continuation of our previous research, wild and farmed mussels from the town of Sozopol, located on the Southern Bulgarian Black Sea coast, were collected to assess and compare the survival rates (stress on stress response, SoS) as a biomarker for the multi-stressor environment. This time we aimed to investigate further if there could be any seasonal differences. Overall, the mussels collected in April had a longer survival time than those collected at the end of January 2024. However, the survival time of wild and farmed mussels had a shorter survival rate in the air than in other studies. The answer to the question “Why is that?” persists.