Yazar "Gurkan, Selin Erturk" seçeneğine göre listele
Listeleniyor 1 - 10 / 10
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A Contribution on the Diet of the Warty Crab, Eriphia verrucosa (Forskal, 1775) by Informative Bayesian Stable Isotope Mixing Models(Maik Nauka/Interperiodica/Springer, 2022) Acar, Secil; Gurkan, Selin Erturk; Ates, A. Suat; Yalçın Özdilek, ŞükranThe present study aims to determine the diet composition of Eriphia verrucosa using an informative and uninformative approach in which the stomach content results were assigned as prior based on this model. A stable isotope mixing model and stomach content analysis were used together to determine the diet and prey-predator relationships of E. verrucosa. A total of 24 crabs and benthic material were collected from depths between 1.5 and 2 m in the Strait of canakkale in July, 2020. The contribution of two different diets was assessed both by prior assignment (informative) and uninformative. According to the stomach content analyses, among the prey, Echinodermata contributed 37% to the diet, followed by Mollusca, especially Gastropoda (18%). In the uninformative model without prior assignment and in the informative model (prior assignment), Gastropoda contributed the most to the diet (57, 66%, respectively).Öğe Assessment of pollution biomarker and stable isotope data in Mytilus galloprovincialis tissues(Springer, 2019) Yalçın Özdilek, Şükran; Demir, Neslihan; Gurkan, Selin ErturkSuperoxide dismutase (SOD) is one of the antioxidant defense enzymes in mussels and converts the superoxide anion into hydrogen peroxide and this enzyme is used as biomarkers of oxidative damage. As well as many topics in ecology, stable isotopes are also signature for organic and heavy metal pollution in aquatic ecosystems. This study aims to compare the stable carbon and nitrogen values of different mussel tissues and the changes on the SOD values of the same tissues in order to understand the relationship between two mechanisms of bioindicator processes of physiological response of mussel to pollution. The changes in SOD activity in the gill, hepatopancreas, and mantle tissues of Mytilus galloprovincialis with C-13 and N-15 isotopes were assessed in two locations (Kepez and Guzelyal) in Canakkale. The SOD values of mussel samples were found as the gill > hepatopancreas > mantle collected from Kepez and the gill > hepatopancreas collected from Guzelyal. There were no significant differences among the mean SOD values of different tissues. There was enrichment both in nitrogen and carbon isotope values of hepatopancreas tissues both in Kepez and Guzelyal samples. There was a negative correlation between both isotope values and SOD values of samples. As well as SOD values, the isotopic composition of particularly hepatopancreas tissue is a good indicator for evaluation of pollution.Öğe Evaluation of Possible Toxic Effects of Boric Acid in Palourde Clam (Ruditapes decussatus) Through Histological Changes and Oxidative Responses(Springernature, 2024) Gurkan, Selin Erturk; Gurkan, Mert; Saritunc, Volkan; Ibis, Ezgi Can; Gunes, BerkayThe extensive utilization of boric acid, particularly in industrial and agricultural sectors, also engenders concerns regarding the toxicity of boron and its derivatives. Particularly, the behavior of boric acid at increasing concentrations in aquatic ecosystems remains poorly understood. In light of these concerns, this study aimed to investigate the toxicity of boric acid in bivalves, which occupy a critical position in the food chain. Specimens of Ruditapes decussatus, which had not been previously exposed to any pollutants and were cultivated under controlled conditions, were subjected to three different concentrations of boric acid (0.05 mg/L, 0.5 mg/L, and 5 mg/L) in vitro for 96 h. Following the exposure period, the specimens were assessed for histological changes (the mantle, gill, and digestive gland) and specific oxidative parameters (the gill and digestive gland), including superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase, and lipid peroxidation (LPO). The research findings indicated that boric acid primarily induced oxidative damage at the applied concentrations and increased antioxidant levels (p < 0.05). Moreover, although no significant histopathological abnormalities were observed in the examined histological sections, subtle changes were noted. This study evaluated the potential adverse effects of boric acid on bivalves, which are crucial components of the aquatic food chain, utilizing histological and specific physiological parameters following its introduction into aquatic environments. It is anticipated that the findings of this study will contribute to the development of new insights and perspectives regarding the extensive use of boric acid.Öğe Evaluation of the health of Mediterranean mussels ( Mytilus galloprovincialis Lamarck, 1819) distributed in the Çanakkale strait, Turkey(Elsevier Sci Ltd, 2024) Gurkan, Mert; Gurkan, Selin Erturk; Kunili, Ibrahim Ender; Acar, Secil; Ozel, Osman Tolga; Duzgunes, Zehra Duygu; Ture, MustafaThe observation of mortality in Mediterranean mussels ( Mytilus galloprovincialis ) distributed in the & Ccedil;anakkale Strait in recent years was influential in developing the research question for this study. In this study, the presence of bacteria ( Vibrio spp.) and parasites ( Marteilia spp. and Haplosporidium spp.) in mussels collected from Kumkale, Kepez, and Umurbey stations in the & Ccedil;anakkale Strait was investigated seasonally. Microbiological findings, histopathology, oxidative stress enzymes and their gene expressions, lipid peroxidation, lysosomal membrane stability, and changes in haemolymph were examined. In summer samples, both the defence system and the extent of damage were higher in gill tissue. In winter samples, enzyme activities and lipid peroxidation were found to be predominantly higher in digestive gland tissues. Histological examinations and Hemacolor staining revealed the presence of protozoan cysts, and for bacterial examination, molecular analysis performed after culturing revealed the presence of 7 Vibrio species. While the total numbers of heterotrophic bacteria detected in all samples were at acceptable levels, the predominance of Vibrio spp. numbers among the total heterotrophic bacteria detected in almost all samples were noteworthy. The total hemocyte count was calculated as 5.810(4) +/- 0.58 (cells/mm 3 ) in winter and 7.210(4) +/- 1.03 (cells/mm 3 ) in summer. These factors are considered to be possible causes of mussel mortality.Öğe Impact of Nickel Oxide Nanoparticles (NiO) on Oxidative Stress Biomarkers and Hemocyte Counts of Mytilus galloprovincialis(Springernature, 2022) Gurkan, Selin ErturkIn this study, the toxic effects of nickel oxide nanoparticles (NiO-NPs) on the model organism Mediterranean mussel (Mytilus galloprovincialis) gill, digestive gland, and hemolymph tissues for 96 h were investigated. Lipid peroxidation (MDA) determination was performed to reveal the oxidative stress generation potential of nanoparticles, and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) enzyme levels were measured to determine antioxidant responses. Lysosomal membrane stability and total hemocyte counts were performed to determine cytotoxic effects. All parameters were altered in different concentrations of NiO-NPs (2, 20, and 200 mg L-1). The SOD levels increased depending on the concentration (p < 0.05), and the increases in CAT, GPx, and GST levels were lower at 20 mg L-1 concentration (p < 0.05). There was a slight difference between the exposure and the control groups in terms of GR enzyme. The MDA level increased in parallel with the concentration (p < 0.05), the stability of the cell membrane (p < 0.05), and the number of hemocyte cells decreased as a result of exposure (p < 0.05). The results emphasize that NiO-NPs may have negative effects on the aquatic environment.Öğe Influence of Dietary Fennel (Foeniculum vulgare) Essential Oil on Immune-Antioxidant Response in Black Sea Salmon (Salmo labrax PALLAS 1814)(Springer Int Publ Ag, 2025) Ozel, Osman Tolga; Duzgunes, Zehra Duygu; Gurkan, Selin Erturk; Cimagil, RecayiThe work was conducted to investigate the immune and antioxidant status and their-related gene expression in the muscle and liver of Black Sea salmon (Salmo labrax PALLAS 1814) juvenile fed with dietary fennel (Foeniculum vulgare) essential oil in different levels. Fish fed with diets have at different concentrations of fennel essential oil (EO) such as 50, 100, 200, and 400 mg kg-1. Fish with initial weights of 3.52 +/- 0.01 g were placed randomly 45 fish per 50-L fiberglass square tanks (15 in total). Experimental study was carried out as triplicate. Fish fed by hand 3% level of live weight with diets including fennel essential oil at 50, 100, 200 and 400 mg/kg, and control. At the end of 90-day experimental, there were no differences in superoxide dismutase (SOD) and catalase (CAT) in muscle. In liver, the highest glutathione peroxidase (GPx) activity was obtained in F400 group while the highest SOD and CAT were determined in F200 group. As the concentrations of fennel EO in diet increased, SOD activity in liver increased. The addition of fennel EO had no significant impacts on gene expression of CAT in liver and GPx in muscle and liver but decreased SOD expression was obtained in muscle. Besides, liver il1-b gene expression decreased significantly by administration of fennel EO. The fact that essential oils partially increase antioxidant enzyme activity has led to the conclusion that they may play a healing role in the antioxidant defense system. Hovewer, to understand the mechanisms related to the immune-antioxidant response of dietary fennel EO in Black Sea salmon, further research should be conducted on its expression and mode of action on the relevant genes.Öğe Pathological and oxidative stress responses of Mytilus galloprovincialis to Vibrio mediterranei infection: An in vivo challenge(Academic Press Ltd- Elsevier Science Ltd, 2024) Ter, Ummugulsum; Gurkan, Selin Erturk; Gurkan, Mert; Kunili, Ibrahim Ender; Aksoy, EmircanSince the identification of Vibrio mediterranei as a causative agent in mass mortalities of pen shells across the Mediterranean, elucidating its pathogenicity, virulence, and interactions with other bivalves has gained importance. While the cellular and immune responses of bivalves to various Vibrio species have been extensively studied, the infectious characteristics of this Vibrio species, particularly in the context of pen shell outbreaks, remain unclear for other bivalves. Therefore, to evaluate its pathogenicity, we investigated the histological and oxidative effects on the Mediterranean mussel (Mytilus galloprovincialis), a key species in aquaculture. Two distinct infection setups were established: one involving the inoculation of seawater with the bacterial isolate and another involving direct injection of the bacteria into the mussels. After a 24-h exposure period, histological evaluations were conducted on the mantle, gill, and digestive gland tissues of the mussels. Additionally, measurements of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and lipid peroxidation levels were performed in the gill and digestive gland tissues. Oxidative responses were significantly elevated in both infection setups compared to the control group, with the directly injected samples exhibiting the highest oxidative responses (p < 0.05). Histological findings indicated that tissue-specific responses to host-pathogen interactions were consistent under both infection conditions. Notable observations included intense hemocytic infiltration in tissues, epithelial hyperplasia, and vacuolization in the gills, as well as focal necrotic areas in the digestive gland. The findings of this study indicate that V. mediterranei, a relatively novel pathogen, can provoke significant acute immune responses and tissue-level reactions in M. galloprovincialis, a species that is both widely distributed and vital to the food chain. These insights into the potential susceptibility of mussels underscore the need for further comprehensive research and inform the development of effective management strategies.Öğe The effects of aquaculture activities on species composition and diversity of native freshwater fish populations(Edp Sciences S A, 2018) Gurkan, Selin Erturk; Yalçın Özdilek, ŞükranThe rapid development of the aquaculture industry in recent years and the increase in the intensity of production has raised questions regarding potential environmental impacts. Understanding intra- and interspecific relationships between native and cultured species is important for sustainable use of natural resources. This study investigated the spatial and temporal effects of a fish farm constructed next to a river on the relative abundance and diversity of natural fish populations. Sampling was conducted at three stations, upstream and down stream from a trout farm and at a control site, on Kocabas stream in Canakkale (Turkey) monthly between August 2015 and July 2016. There was no significant difference among the three stations in fish diversity. However, a remarkable seasonal and spatial variation in the composition and relative proportion of the indigenous fish assemblage were observed among the three stations. In conclusion, the fish farm might have influenced species composition and relative abundances particularly at the downstream station.Öğe The effects of biosynthesized silver nanoparticle on oxidative stress parameters in model organism Artemia salina (Linnaeus, 1758)(Taylor & Francis Inc, 2024) Unal, Ilkay; Gurkan, Selin ErturkEvaluation of the effects of nanomaterials in various habitats and living groups is increasing with in vitro and in vivo studies. This study aims to describe a biological procedure to synthesize silver nanoparticles using an extract of Marrubium astracanicum and to determine the aquatic environment's oxidative stress on Artemia salina. Silver nanoparticle formation was visually observed with color change. Its structural properties, such as size, shape, morphology, and stability, were characterized by UV-Vis spectrophotometer, TEM, SEM, XRD, and DLS analyses. TEM image showed that the synthesized AgNPs have a size of between 20 and 50 nm. The effects of biosynthesized silver nanoparticles at different concentrations (control,0.2, 1, 5, 10, 25, and 50 mg/mL) and exposure times (24, 48 and 72 h) on total glutathione (GSH) and lipid peroxidation levels (MDA) were investigated on the Artemia salina organism, which is one of the most common saltwater organisms frequently used in ecotoxicity tests.Öğe The effects of trout culture on diet and food availability of native freshwater fish populations(Wiley, 2019) Gurkan, Selin Erturk; Yalçın Özdilek, ŞükranCultivation of a species or population and distribution to various regions has raised the idea of negative impacts on native species. The effect of non-native species on native species may be caused by competition for source, predation, hybridization, and parasite/disease transport. The present study aims to evaluate the possible effects of a trout farm established on the banks of Kocabas Stream (canakkale, Turkey) on feeding characteristics of some freshwater fish (Phoxinus phoxinus, Barbus oligolepis, and Squalius cii). The samples were collected monthly over a year at two stations located before and after the trout farm and at a control station on the tributary not impacted by the effects of the farm. Fish and environmental samples were gathered monthly with an electroshocker and some fishing tools between August 2015 and July 2016. The fish diet and resource incorporation into biomass were evaluated by gut content and stable isotope analyses. Changes in diet preferences when the species are exposed to source stresses and some individuals fed on farm-based feed contaminated from the farm in Kocabas Stream. In this study, it was observed that native fish populations in aquaculture regions were influenced by diet preferences. Designing enclosed systems limiting feed and waste transit in aquaculture establishments may be suitable for sustainability of these species.
