Browsing by Author "Sönmez A.Y."

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An assessment of the effects of climate change on annual streamflow in rivers in Western Turkey
(2018-01-01) Kale S.; Hisar O.; Sönmez A.Y.; Mutlu F.; Filho W.L.
Global warming and its impacts are known to cause serious problems in sustainability of natural resources. In this study, change-point analysis and trend analysis were applied to climatic (temperature, precipitation, evaporation) and streamflow data for Tuzla, Gediz and Büyük Menderes rivers. Box-Jenkins technique and ARIMA model were used for trend analysis. Results showed that there were decreases in streamflow of all rivers. The paper suggests that climate change effects on streamflow could be changeable and that many factors (anthropogenic effects, geographical location, agricultural activities) should be considered. Management strategies specified regionally are required to mitigate the potential climate change effects.
Antioxidant and immunostimulant responses in rainbow trout (Oncorhynchus mykiss) fed with cherry stem extract
(2022-02-01) Amoush O.A.A.; Bilen S.; Sönmez A.Y.; Elp M.
We examined antioxidant enzyme activities, immune response, blood parameters and growth performance of rainbow trout fed with different doses of cherry stem (CS) aqueous methanolic extract. Four different feeds containing CS extract in different doses, 0% (control), 0.1 (0.1% CS), 0.5 (0.5% CS) and 1% (1% CS), as treatment feeds were prepared. Fish were fed with the diets for 60 days. The results showed that superoxide dismutase (SOD) activity was significantly increased on 20th and 60th days in all CS-treated fish groups. On 40th day, only 0.1% CS fish group had an elevated SOD activity compared with that of control (p < 0.05). Catalase (CAT) was significantly increased on 20th day of the study in 0.1 and 0.5 CS-treated groups compared with control and this increase was observed in all treatment groups on 40th day. However, in all fish groups, CAT was significantly decreased on 60th day. Glutathione peroxidase (GPx) was increased on 20th day in 0.1% CS fish group and in all treatment groups on the 60th day. G6PDH showed no significant difference at the end of experiment compared to the control. Similar result to that of G6PDH was obtained on lipid peroxidation. Haematocrit values of all the CS-treated fish groups were significantly increased at the end of the study. Growth did not differ among fish groups. Results indicated that 0.1% and 0.5% CS could be used as the dietary supplementation in rainbow trout.
Antioxidant enzyme activities and immune responses in rainbow trout (Onchorhynchus mykiss) juveniles fed diets supplemented with dandelion (Taraxacum officinalis) and lichen (Usnea barbata) extracts
(2021-08-01) Salem M.O.A.; Salem T.A.; Yürüten Özdemir K.; Sönmez A.Y.; Bilen S.; Güney K.
In the present study, antioxidant activity, immune responses, and growth performance of rainbow trout (Onchorhynchus mykiss) juveniles fed with diets supplemented with dandelion (Taraxacum officinalis) and lichen (Usnea barbata) extracts were assessed. Four different concentrations of aqueous methanolic extract of the plants (0% (control), 0.1%, 0.5%, and 1% (D, dandelion; L, lichen) were added to the diets, and fish were fed for 75 days. On the 15th, 45th, and 75th day of the study, liver antioxidant enzyme activities were determined, and immune responses were determined every 15th day. The results showed that SOD activity increased in the fish group of 0.1% D on the 15th and 45th day compared to control; however, it was lower in all the lichen extract-treated groups than in control at almost all sampling times, except on the 15th day in the 0.1% L group. CAT activity showed an increased value (P < 0.05) in 0.5% L and 1% L treated fish groups on the 15th day, in fish of 1% D and 1% L groups on 45th and on 75th day in 0.1% D group. GPX activity increased on the 15th day of the study in fish of 0.1% D group, on the 45th day in 1% D and 1% L groups and on the 75th day in fish of 0.5% D, 0.1% D, and 0.5% L groups (P < 0.05). G6PDH enhanced in all treatment groups compared to control on the 15th day, except in 0.1% L and 0.5% L groups. An elevated G6PDH activity was also observed on the 75th day of the study in 0.5% D, 1% D, and 0.5% L fish groups. An increase on lipid peroxidation (LP) was observed in all L groups on the 45th day of the study. Lysozyme activity was determined to be the highest in 0.5% and 1% L on the 45th day, in 0.1% L on the 60th day and in the 0.5% L fish group on the 75th day compared to control (P < 0.05). Myeloperoxidase was found to be the highest at the end of the study in 1% L fish group compared to the control (P < 0.05). In conclusion, we suggest the use of dandelion to combat oxidative stress and to lower FCR and the use of lichen to modulate the immune response in rainbow trout. The use of such products will be economical for aquaculture and harmless for the environment.
Assessing contamination in sturgeons grown in recirculating a uaculture system by Lu - Biosensors and metal accumulation
(2016-01-01) Sönmez A.Y.; Sazykina M.; Bilen S.; Gültepe N.; Sazykin I.; Khmelevtsova L.E.; Kostina N.V.
In the present study, it was aimed to assess of the quality of fish grown in a recirculation aquaculture system (RAS). For this purpose, three sturgeon species especially i en e el en tae tii, i en e ae ii, and i en e tellat were investigated. Concentrations of certain metals (Cu, Cd, Pb, Zn, Fe, Ni) in gills, liver and muscle samples were examined. Metal concentrations in i en e el en tae tii were; Fe:172.43-196.52 μg g-1, Cd: 0.21-0.33 μg g-1, Cu: 29.65-45.11 μg g-1, Ni: 0.52-0.86 μg g-1, Pb: 14.24-19.63 μg g-1, and Zn: 60.13-88.15 μg g-1. In i en e ae ii, metal concentrations were; Fe: 151.47-182.32 μg g-1, Cd: 0.18-0.36 μg g-1, Cu: 27.17-38.52 μg g-1, Ni: 0.72-0.98 μg g-1, Pb:16.45-25.16 μg g-1, and Zn: 72.14-95.41 μg g-1. Concentrations in i en e tellat were; Fe: 206.39-262.38 μg g-1, Cd: 0.26-0.39 μg g-1, Cu:30.26-55.63 μg g-1, Ni: 0.54-0.87 μg g-1, Pb:14.36-21.51 μg g-1, and Zn: 53.52-82.15 μg g-1. In general, the highest metal levels were found in i en e ae ii. Negative biological effects caused by the presence of various toxicants in fish tissues were studied with bacterial lux-biosensors. These assays revealed that the accumulation of genotoxicants, oxidative stressors, and substances causing damage to proteins and membranes mainly occurred in gills and to a smaller extent in liver. i en e ae ii showed the highest accumulation of toxic substances according to the bacterial luxbiosensor assays.
Climate change effects on annual streamflow of filyos river (Turkey)
(2020-06-01) Sönmez A.Y.; Kale S.
The main purpose of this study was to estimate possible climate change effects on the annual streamflow of Filyos River (Turkey). Data for annual streamflow and climatic parameters were obtained from streamflow gauging stations on the river and Bartın, Karabük, Zonguldak meteorological observation stations. Time series analysis was performed on 46 years of annual streamflow data and 57 years of annual mean climatic data from three monitoring stations to understand the trends. Pettitt change-point analysis was applied to determine the change time and trend analysis was performed to forecast trends. To reveal the relationship between climatic parameters and streamflow, correlation tests, namely, Spearman’s rho and Kendall’s tau were applied. The results of Pettitt change-point analysis pointed to 2000 as the change year for streamflow. Change years for temperature and precipitation were detected as 1997 and 2000, respectively. Trend analysis results indicated decreasing trends in the streamflow and precipitation, and increasing trend in temperature. These changes were found statistically significant for streamflow ( p < 0.05) and temperature ( p < 0.01). Also, a statistically significant ( p < 0.05) correlation was found between streamflow and precipitation. In conclusion, decreasing precipitation and increasing temperature as a result of climate change initiated a decrease in the river streamflow.
Cyclopamine induced expression of immune-related genes in rainbow trout (Oncorhynchus mykiss) head kidney leukocytes
(2018-01-01) Sönmez A.Y.; Özdemir R.C.; Bilen S.; Yürüten Özdemir K.
This study investigated the effect of cyclopamine, a hedgehog signaling inhibitor, on immune-related gene expression in rainbow trout head kidney leukocytes in vitro. At 1h sampling time COX 2, IFN-2, TNF-α, C3, MHC-II, Il-1β, IL-12, IL-10, and IL-6 increased significantly in groups exposed to cyclopamine at 30 μg/ml. However, in groups exposed to 10 and 20 μg/ml cyclopamine, the expression of these genes decreased significantly. At 4h sampling time, levels of COX-2, IFN-1, IFN-2, TNF-α, TGF-β, IgT, and MHC-II in groups exposed to 20 μg/ml cyclopamine increased. At 8h sampling time, COX2, IFN-Reg, and TNF-α expression in groups exposed to 10 and 30 μg/ml cyclopamine increased significantly compared to those in the controls. Conversely the expression decreased significantly for almost all other genes. At 12h sampling time, almost all genes increased significantly in groups exposed to 10 μg/ml cyclopamine compared to those in the controls. Notably, after 24h, the gene expression in all groups significantly decreased compared to the controls. Our results suggest that the activation of cyclopamine can be a useful tool for the examination of immune-related gene expression in the rainbow trout.
Dietary flaxseed (Linum usitatissimum) oil supplementation affects growth, oxidative stress, immune response, and diseases resistance in rainbow trout (Oncorhynchus mykiss)
(2023-07-01) Salem M.O.A.; Taştan Y.; Bilen S.; Terzi E.; Sönmez A.Y.
This paper describes the effects of flaxseed (Linum usitatissimum) oil (FSO) as a feed additive on growth performance, oxidative stress, immunity, and disease resistance in rainbow trout (Oncorhynchus mykiss). Eight-hundred-and-forty rainbow trout individuals (mean weight: 25.66 ± 1.33 g) were fed with different doses of FSO (0.5, 1, and 1.5%) ad libitum two times a day for 9 weeks. At the end of the feeding, growth performance was evaluated and the fish were challenged with two different bacteria (Yersinia ruckeri and Aeromonas hydrophila). At the end of the 3rd, 6th, and 9th weeks, blood and tissue samples were taken from 9 fish per treatment to evaluate innate immune response, cytokine gene expression levels, antioxidant enzyme activities and lipid peroxidation levels, and digestive enzyme activities. Determination of haematological parameters and histological examination was also carried out to evaluate the general health status of the fish. Results showed that the final weight and specific growth rate of FSO-supplemented fish increased significantly (p < 0.05). FSO-supplemented fish showed higher resistance to Y. ruckeri than the control group (p < 0.05). However, survival rates of all groups in A. hydrophila challenge test were similar (p > 0.05). Among the investigated innate immune response parameters, the potential killing activity of phagocytes, myeloperoxidase activity, and lysozyme activity increased in the FSO-supplemented groups (p < 0.05). Almost all cytokine gene expression levels in the experimental groups up-regulated especially after 9 weeks of feeding in the head kidney and intestine (p < 0.05). Similarly, superoxide dismutase and catalase activities were found to be significantly higher in the FSO group than in the control (p < 0.05) whereas, the lipid peroxidation levels drastically declined as a result of the FSO supplementation (p < 0.05). These results suggest that FSO can improve growth, enhance immune response, and lower oxidative damage in rainbow trout when supplemented at the rates of 0.5–1.5% for 9 weeks.
Effect of Aqueous Methanolic Extract of Pomegranate Peel (Punica granatum) and Veratrum (Veratrum album) on Oxidative Status, Immunity and Digestive Enzyme Activity in Rainbow Trout (Oncorhynchus mykiss)
(2022-01-01) Sönmez A.Y.; Bilen S.; Yürüten Özdemir K.; Alagöz K.; Özçelik H.
Aqueous methanolic extracts of pomegranate peel (Punica granatum) and veratrum (Veratrum album) were evaluated for their effects of supplementation in fish diets on oxidative status, digestive enzymes and immunity of rainbow trout fingerlings (Oncorhynchus mykiss). Three different concentrations of pomegranate 250 (P250), 500 (P500) and 1000 (P1000) mg kg-1 and veratrum 250 (V250), 500 (V500) and 1000 (V1000) mg kg-1 were added to the diet and the fish were fed these diets for 60 days over a control diet without any supplementation (P0 and V0, respectively). Immune responses and oxidative status of fish were evaluated every 20 days. Digestive enzyme activity and growth performances were determined at the end of study. We observed that the respiratory burst activity significantly increased (P<0.05) at the end of the study compared to control except in the V500 fish group. Lysozyme was increased on the 20th and 40th day of the study in all experimental groups compared to the control group (P<0.05). Myeloperoxidase activity was observed to increase on the 40th day in veratrum treated groups and significantly decreased (P<0.05) on the 60th day in all groups compared to the control. Haematological responses showed a declining trend in all the groups supplemented with veratrum extract. SOD activity increased in pomegranate groups while no differences were observed on catalase activity. G6PDH activity was observed to decline in the veratrum groups, however, GPx activity significantly increased (P<0.05) in V500 and V100 groups. Lipid peroxidation was determined at the lowest level on the 20th and 40th days of the study in P1000 and V250 fish groups. The study indicated a positive impact of pomegranate peel extract on the immunity of rainbow trout at moderate doses of supplementation.
Effects of dietary Astragalus caudiculosus (Boiss & Huet, 1856) supplementation on growth, hematology, antioxidant enzyme activities, and immune responses in rainbow trout (Oncorhynchus mykiss Walbaum, 1792)
(2022-03-01) Sönmez A.Y.; Bi̇len S.; Taştan Y.; Nezih Kenanoğlu O.; Terzi E.
The potential dietary utilization of Astragalus caudiculosus (AC) in rainbow trout (Oncorhynchus mykiss) was investigated. Four different fish groups (control, AC1, AC2.5, and AC5) were assigned and received the AC-containing diet for 90 days at the rates of 0, 1, 2.5, and 5%, respectively. Results indicated that the growth performance of the AC supplemented fish improved significantly (P < 0.05). Among non-specific immune parameters examined, while lysozyme activity of the AC supplemented fish increased (P < 0.05), oxidative radical production decreased in AC1 and AC2.5 fish groups (P < 0.05) but did not differ in the AC5 group (P > 0.05) compared to the control. Moreover, myeloperoxidase activity was not affected by the AC supplementation (P > 0.05). All pro-inflammatory and anti-inflammatory cytokine gene expressions, except IL-1β, were up-regulated, especially in the fish groups fed with 2.5 and 5% AC supplemented feed (P < 0.05). AC administration caused an elevation in GPx and G6PDH activities, and a decrease in SOD, CAT, and lipid peroxidation (P < 0.05). Overall, AC extract was found to improve the growth, antioxidant status, and immune response of the fish.
Effects of ribwort plantain (Plantago lanceolata) extract on blood parameters, immune response, antioxidant enzyme activities, and growth performance in rainbow trout (Oncorhynchus mykiss)
(2020-08-01) Elbesthi R.T.A.; Özdemir K.Y.; Taştan Y.; Bilen S.; Sönmez A.Y.
In this study, we examined changes occurred in blood parameters, immune responses, antioxidant enzyme activities, and growth performance of rainbow trout (Oncorhynchus mykiss) administered with ribwort plantain (RP) through feed. Fish (mean weight 36.56 ± 1.99 g) were fed a diet supplemented with an aqueous methanolic extract of RP at variable doses, 0 (control), 1 (RP1), 2 (RP2), and 3 g kg−1 (RP3) for 90 days. The final weight, weight gain, and specific growth rate were significantly increased in RP1, RP2, and RP3 treatment groups compared to that of the control. Among examined blood parameters, hemoglobin value in RP1 group (9.77 ± 0.10 g dl−1) only was significantly high on the 30th day of the study. When immune response parameters were evaluated, we observed that oxidative radical production and lysozyme activities were affected positively in experimental groups (P < 0.05). The highest oxidative radical production was determined in fish of RP3 group. Glutathione peroxidase and glucose 6 phosphate dehydrogenase were increased in RP3 group compared to control and other treatment groups. Based on these results, it is concluded that ribwort plantain promotes growth, enhances immune responses and antioxidant enzyme activities in rainbow trout, and therefore, may be used in aquaculture.
Effects of white mustard (Sinapis alba) oil on growth performance, immune response, blood parameters, digestive and antioxidant enzyme activities in rainbow trout (Oncorhynchus mykiss)
(2022-12-01) Salem M.O.A.; Taştan Y.; Bilen S.; Terzi E.; Sönmez A.Y.
A study was conducted to evaluate the effects of dietary supplementation of white mustard (Sinapis alba) oil (WMO) on growth performance, immune responses, digestive and antioxidant enzyme activities in juvenile rainbow trout (Oncorhynchus mykiss). For this purpose, fish (initial weight: 25.77 ± 0.13 g) were divided into four experimental groups in triplicate and fed ad libitum twice a day with diets containing WMO at 0 (control), 0.5, 1, and 1.5% of diet for 9 weeks. Three fish from each tank (n:9 per treatment) were sampled on 21st, 42nd, and 63rd days for further analyses. At the end of the feeding period, fish were challenged with Aeromonas hydrophila and Yersinia ruckeri in two separate experimental setups. Results showed that final weight, weight gain, and specific growth rate were significantly increased in all experimental groups compared to the control. Feed conversion ratio was similar among treatments. Respiratory burst and potential killing activity decreased in all experimental groups compared to the control (P < 0.05). Lysozyme and myeloperoxidase activities were elevated in all experimental groups at the end of the experiment compared to the control (P < 0.05). Cytokine gene expressions in the head kidney and intestine were elevated in all experimental groups compared to that of the control in general (P < 0.05). Hematological responses of the experimental fish groups were similar to that of the control (P > 0.05). Pepsin and trypsin levels decreased in all experimental groups (P < 0.05). In terms of antioxidant enzyme activities, significant improvement in liver superoxide dismutase, catalase, and glutathione s-transferase activities in all treatment groups were determined (P < 0.05). In addition, a significant decline in liver lipid peroxidation levels was recorded in all treated groups at all sampling times compared to the control (P < 0.05). At the end of this feeding trial, no significant differences (P > 0.05) were observed in survival against A. hydrophila among experimental groups compared to the control (P > 0.05). However, increased survival against Y. ruckeri was determined in experimental fish groups (P < 0.05). This study suggests that white mustard oil had a favorable effect on the overall health and growth of rainbow trout.
Growth performance and antioxidant enzyme activities in rainbow trout (Oncorhynchus mykiss) juveniles fed diets supplemented with sage, mint and thyme oils
(2015-02-01) Sönmez A.Y.; Bilen S.; Alak G.; Hisar O.; Yanık T.; Biswas G.
This study evaluated effects of dietary supplementation of sage (Salvia officinalis), mint (Mentha spicata) and thyme (Thymus vulgaris) oils on growth performance, lipid peroxidation level (melondialdehyde, MDA) and liver antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; glucose-6-phosphate dehydrogenase, G6PD; glutathione reductase, GR; glutathione-S-transferase, GST and glutathione peroxidase, GPx) in rainbow trout (Oncorhynchus mykiss) juveniles. For this purpose, triplicate groups of rainbow trout were fed daily ad libitum with diets containing sage, mint and thyme oils at 500, 1,000 and 1,500 mg kg−1 for 60 days. While weight gain percentage of fish fed the diets containing sage and thyme oils was significantly higher than the control group, that of fish fed mint oil was the lowest. Similarly, specific growth rate was found to be the highest in all groups of the sage and thyme oil feeding and the lowest in the mint groups. Moreover, feed conversion ratio was significantly higher in the mint oil administered groups. Survival rate was also significantly reduced in the fish fed the diet containing mint oil. It was observed that SOD, G6PD and GPx activities were significantly increased in liver tissues of all the treated fish groups compared to that of control diet-fed group. However, CAT, GST and GR activities were significantly decreased in experimental diet-fed fish groups at the end of the experiment. On the other hand, a significant reduction was found in MDA levels in the fish fed the diets with sage and thyme oils compared to control and mint diets on the 30th and 60th days of experiment. Overall, dietary inclusion of sage and thyme oils is effective in enhancing rainbow trout growth, reduction in MDA and least changing antioxidant enzyme activities at a low level of 500 mg kg−1 diet, and they can be used as important feed supplements for rainbow trout production.
Growth, Blood Parameters, Immune Response and Antioxidant Enzyme Activities in Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792) Fed Diets Supplemented with Fumitory (Fumaria officinalis)
(2023-01-01) Filogh A.; Bilen S.; Sönmez A.Y.; Elp M.
In a feeding experiment for 75 days, the effects of fumitory (Fumaria officinalis) extract on growth, haematology, immune response and antioxidant enzyme activities in rainbow trout (Oncorhynchus mykiss) were evaluated. The aqueous methanolic extract of the plant was mixed with feeds at three different levels, 0.1% (FO1), 0.2% (FO2) and 0.3% (FO3), and feed with no plant extract donated as the control. All four groups (mean initial weight: 13.02 ± 0.02 g) were fed with the prepared diets twice daily ad libitum in a triplicate experiment. Blood and liver samples were taken from the fish on 15, 30, 45, 60 and 75 days. Also, overall growth parameters were determined based on body weight data recorded from all fish before and at the end of feeding trial. Results indicated that there were variations in nonspecific immune parameters (lysozyme, myeloperoxidase and oxidative radical production), but supplementation of the plant extract did not affect the immune response of the fish significantly. On the other hand, there was a general increase in the antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase) evaluated in this study. Furthermore, possibly the most remarkable finding of the study is that the growth performance in the FO3 group was roughly 30% higher than that of the control group. Considering all findings in the present study, we conclude that 0.3% supplementation of fumitory extract would be beneficial for rainbow trout farming with respect to elevated growth and antioxidant status.
Metals in two species of fish in Karasu River
(2012-12-01) Sönmez A.Y.; Yaganoglu A.M.; Arslan G.; Hisar O.
In this study, cadmium (Cd), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) levels were determined in the tissues (muscle, liver and gills) of two fish species, Capoeta capoeta umbla and Chalcalburnus mosullensis, collected from three stations of the Karasu River. The lowest metal accumulation was detected in the muscle tissues. Moreover there was some variability in the metal concentrations measured in the same tissues from samples obtained from the three different stations. A positive correlation was observed for the concentration of metal pairs Fe-Cu, Fe-Zn, Ni-Pb, Pb-Zn. These findings were also compared with national and international food standards, and Pb and Cd concentrations were determined to be above the level set by the standards. In conclusion, it was supposed that excessive consumption of these two fish species, which already occurs in this region, might pose a public health risk. © Springer Science+Business Media New York 2012.
Oral administration of Sargassum polycystum extracts stimulates immune response and increases survival against Aeromonas hydrophila infection in Oncorhynchus mykiss
(2021-10-01) Sönmez A.Y.; Bi̇len S.; Taştan Y.; Serag K.J.B.; Toring C.C.; Romero J.B.; Kenanoğlu O.N.; Terzi E.
This study investigated the immunomodulatory effects of Sargassum polycystum extract administration in rainbow trout (Oncorhynchus mykiss). S. polycystum methanolic extract was administered orally using feeding needles to individual rainbow trout at the dose of 0 (control), 1 (S1), 3 (S3) and 5 (S5) mg/100 μl/per fish twice a day for 7 days. On 1st, 5th, 3rd and 7th day, blood and tissues were collected from the fish and changes in humoral immune responses and immune‐related gene expressions were determined. The result of oxidative radical production showed no difference during early stage of the experiment and was lately decreased (P < 0.05). Lysozyme activity increased on 3rd and 7th day of the study in S5 fish group and on 5th day in S3 group compared to control (P < 0.05). Myeloperoxidase activity had an increased level on the 1st and 3rd day in S1, S5 and S5 fish groups, respectively. IL-1β gene was significantly up-regulated in kidney and intestine in all experimental groups (except on the 1st day, in the intestine of S5 fish group) compared to control (P < 0.05). IL-8 gene expression was elevated on 1st and 3rd day in kidney of all experimental fish groups. IL-6 transcript enhanced in a dose-dependent manner on 3rd and 7th day. IL-10 and IL-12 genes were also up-regulated. Survival in all treated fish groups challenged with Aeromonas hydrophila was significantly increased compared to that of control. The highest survival rate was recorded in S5 fish group (83.65%) followed by S3 fish group (82.62%). Our results suggest that S. polycystum aqueous methanolic extract is an effective immunostimulant and provide protection against A. hydrophila infection in rainbow trout at a dose of 3–10 mg/20 g body weight/day.
Phylogeography and population dynamics of the Eastern Mediterranean whiting (Merlangius merlangus) from the Black Sea, the Turkish Straits System, and the North Aegean Sea
(2020-09-01) Şalcıoğlu A.; Gubili C.; Krey G.; Sönmez A.Y.; Bilgin R.
In this study, the taxonomic resolution and phylogenetic relationship of two presumed subspecies of Merlangius merlangus, namely M. m. euxinus and M. m. merlangus, were investigated. In addition, the effect of the Turkish Straits System on the evolutionary history and genetic structure of M. merlangus, was explored. The mitochondrial cytochrome c oxidase subunit 1 and cytochrome b genes, and the nuclear recombination activating gene-1 were analysed. Our results indicate no clear distinction between the two presumed subspecies, which is attributed to the low resolution of recombination activating gene-1 and/or presence of potential gene flow between the two subspecies. The temporal pattern of divergence between the two presumed subspecies related to the Last Glacial Maximum (219 Kya), whereas the expansion of each main sampling location occurred after the flooding of the Black Sea by salt water from the Mediterranean (5 Kya), following a period of stability. Additionally, significant genetic differences are observed among the North Aegean samples and the collections from the Turkish Straits System and the Black Sea, along with some significant structure among sampling sites located in the Turkish Straits System and Black Sea. The lower genetic variability of the eastern Mediterranean M. merlangus when compared to Atlantic ones might be due to a potential population bottleneck before the last glacial period, a trend that is commonly found in these waters.
Spurge (Euphorbia rigida) exhibits anaesthetic effect in rainbow trout (Oncorhynchus mykiss) without altering plasma cortisol levels
(2021-11-01) Alagöz K.; Paruğ Ş.; Taştan Y.; Bilen S.; Sönmez A.Y.
This study was conducted to investigate a potential new organic anaesthetic for aquaculture practices. Aqueous macerate of spurge stem (Euphorbia rigida) was obtained by adding 200 g of plant powder to 1.5 L of distilled water and applied to rainbow trout (Oncorhynchus mykiss) at 5 different concentrations (30000, 40000, 50000, 60000 and 70000 µL L−1) to determine induction (loss of equilibrium and deep anaesthesia) and recovery (recovery of equilibrium and full recovery) durations. In addition, plasma cortisol levels of fish within 0 hours were determined to evaluate stress response. It was determined that there were 4 concentrations that can be used as suitable anaesthetics for rainbow trout: 40000, 50000, 60000 and 70000 µL L−1. These concentrations provided deep anaesthesia in 196.67±1.45, 173.00±11.24, 138.33±8.29 and 136.33±5.23 seconds, respectively. Plasma cortisol levels of the mentioned groups were measured as 4.49±1.04, 8.64±0.73, 8.18±0.64 and 9.64±0.78 ng mL−1, respectively. On the other hand, the plasma cortisol level of the control group (anaesthetized with 2-phenoxyethanol) was 10.95±0.89 ng mL−1. These findings suggest that 40000–70000 µl L−1 of E. rigida can be used as an alternative anaesthetic in rainbow trout. However, further studies need to be conducted to evaluate the long term effects of the plant, especially in consecutive use.
The sexually dimorphic adipose fin is an androgen target tissue in the brown trout (Salmo trutta fario)
(2013-04-01) Hisar O.; Sönmez A.Y.; Hisar S.A.; Budak H.; Gültepe N.
An investigation has been described on the relationship of body length, age and sex with adipose fin length and the number of androgen receptor (AR)-containing cells in the adipose fin as a secondary sexual characteristic for brown trout (Salmo trutta fario). Firstly, body and adipose fin lengths of 2- to 5-year-old brown trout were measured. Thereafter, these fish were killed by decapitation, then their sexes were determined, and adipose fins were excised. The cellular bases of AR binding activities in the adipose fins were analyzed with an antibody against human/rat AR peptide. Immunocytochemistry and western blotting techniques were performed with this antibody. Analysis of morphological measurements indicated that body length and age had a linear relationship with adipose fin length. The coefficients of determination for the body length and age were 0. 92 and 0. 85 in the male fish and 0. 76 and 0. 73 in the female fish against the adipose fin length, respectively. At 2 years of age, cells in the adipose fin did not exhibit AR immunoreactivity. However, AR-immunopositive cells were abundant in the adipose fin of 3- to 5-year-old fish. Moreover, the number of AR-immunopositive cells was significantly (P < 0. 05) high in males and increased with age. These observations indicate that the adipose fin in the brown trout is a probable target for androgen action and that tissue function or development may to some extent be androgen dependent. In addition, it is likely that such an effect will be mediated by specific androgen receptors. © 2012 Springer Science+Business Media B.V.
Trend analysis and forecasting of the Gökırmak River streamflow (Turkey)
(2020-09-01) Arslan G.; Kale S.; Sönmez A.Y.
The objective of this paper is to determine the trend and to estimate the streamflow of the Gökırmak River. The possible trend of the streamflow was forecasted using an autoregressive integrated moving average (ARIMA) model. Time series and trend analyses were performed using monthly streamflow data for the period between 1999 and 2014. Pettitt's change point analysis was employed to detect the time of change for historical streamflow time series. Kendall's tau and Spearman's rho tests were also conducted. The results of the change point analysis determined the change point as 2008. The time series analysis showed that the streamflow of the river had a decreasing trend from the past to the present. Results of the trend analysis forecasted a decreasing trend for the streamflow in the future. The decreasing trend in the streamflow may be related to climate change. This paper provides preliminary knowledge of the streamflow trend for the Gökırmak River.
Use of Onion (Allium cepa) and Garlic (Allium sativum) Wastes for the Prevention of Fungal Disease (Saprolegnia parasitica) on Eggs of Rainbow Trout (Oncorhynchus mykiss)
(2020-10-01) Özçelik H.; Taştan Y.; Terzi E.; Sönmez A.Y.
This study was designed to prevent fungal disease (Saprolegnia parasitica) that occurs on rainbow trout eggs (Oncorhynchus mykiss) by using wastes of onion (Allium cepa) and garlic (Allium sativum) plants. For this purpose, fertilized rainbow trout eggs were exposed to garlic skin, garlic stem and onion skin aqueous methanolic extracts by bathing in concentrations of 0.4, 0.8, 1.6 and 3.2 g/L, whereas the control group was left untreated. The larvae in all groups were monitored until they become free-swimming larvae, the number of eggs died due to fungus was recorded, and the data obtained from experimental groups and control group were compared. As a result, it was determined that onion skin had no effect on the number of eggs that died due to fungus (p >.05), while garlic skin and garlic stem extracts significantly reduced the number of fungal infestations without affecting the number of live larvae or the embryological development of the eggs (p <.05). In light of these data, we conclude that garlic skin (0.4, 0.8, and 1.6 g/L) and garlic stem (0.8 and 1.6 g/L) aqueous methanolic extracts are effective at preventing Saprolegnia parasitica infestation on rainbow trout eggs and may be used in aquaculture.