Browsing by Author "Karatas, Boran"

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Comparison of Rainbow Trout (Oncorhynchus Mykiss) and Brown Trout (Salmo Trutta Ssp) Dual Culture in Different Ratios and Growth Performances
(Zoological Soc Pakistan, 2017) Karatas, Boran; Arabaci, Muhammed; Onalan, Sukru
The objective of the present study is to analyze the growth performance of rainbow trout (Oncorhynchus mykiss) (G) and brown trout (Salmo trutta ssp) (K) monoculture and polyculture in 75-25%, 66-34% and 50-50% stocking rates and its effects on food utilization and to determine the results with respect to aquaculture. Stocking was conducted in 5 different ratios in the study and each different stocking ratio was considered as a group and 24 fish were used in each group. Study groups were named based on stocking ratio percentages as G, K, G75K25, G66K34 and G50K50 and the study lasted 80 days. When the growth parameters in polycultures of rainbow trout and brown trout are considered, it was determined that the growth rates were not statistically different between rainbow trout monoculture and rainbow trout G75K25 and G50K50 groups, however rainbow trout in G66K34 experienced statistically significantly less growth when compared to others (p<0.05). Growth parameters of brown trout in polycultures demonstrated that the best growth was observed in G66K34 polyculture group (p<0.05). Study results showed that there was no significant difference between the groups based on food conversion coefficients and survival rates (p>0.05). As a result, it was determined that brown trout monoculture was the most advantegous group followed by G50K50 polyculture group, and when ecological and environmental parameters are concerned, G75K25 group, which consumed statistically significantly less food and demonstrated a lower food conversion ratio, would be more beneficial, and for fish breeders, who would like to increase the growth rate of the trout, G66K34 polyculture group would be more useful when compared to brown trout monoculture.
Dietary Cyanus Depressus (M. Bieb.) Soják Plant Extract Enhances Growth Performance, Modulates Intestinal Microbiota, and Alters Gene Expression Associated With Digestion, Antioxidant, Stress, and Immune Responses in Rainbow Trout (Oncorhynchus Mykiss)
(Springer, 2024) Karatas, Boran
This study aimed to assess the effects of dietary Cyanus depressus (CD) extract on rainbow trout (Oncorhynchus mykiss) physiology and health. Fish with an average weight of 3.29 +/- 0.34 g were allocated to four feeding groups, receiving diets containing CD extract at doses of 0 (Control), 0.5 (CD05), 1 (CD1), and 2 (CD2) g kg-1 for a period of 60 days. Results revealed significant improvements in final body weight, weight gain, and specific growth rate in groups supplemented with 1 and 2 g/kg of CD extract. Lipase activity increased notably in fish fed with CD0.5, CD1, and CD2 diets. The CD1 group exhibited the highest trypsin activity, while the groups receiving 1 g/kg and 2 g/kg of CD extract displayed the highest amylase activity. Analysis of gene expression levels for superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) showed marked increases across all groups compared to the control, with the most significant enhancement observed in fish fed with 2 g/kg of CD extract. Significant variations were observed in the expression of immunity-related genes among the treatments, with the highest expression levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) found in groups fed a diet enriched with CD extract. The increased activity of immune-related genes was more prominent in fish fed 2 g/kg of CD extract than in the control group. Notably, in fish fed with CD extract, heat shock protein 70 (HSP70) gene expression increased in the CD2 group, decreased in the CD05 group, and remained statistically unchanged in the CD1 group compared to the control. Additionally, supplementation with CD extract altered the composition and abundance of the intestinal microbiota in rainbow trout. In conclusion, our study suggests that Cyanus depressus extract has significant potential for enhancing various physiological and health aspects of rainbow trout, particularly when supplemented at 2 g/kg.
Dietary Pot Marigold (Calendula Officinalis) Extract Improved the Growth Performance, Expression of Digestive Enzymes, Antioxidant Enzymes and Immune-Related Genes in Rainbow Trout (Oncorhynchus Mykiss)
(Springer, 2025) Kaya, Dogukan; Karatas, Boran; Guroy, Derya
The current study was designed to test the dietary pot marigold (Calendula officinalis) extract on growth performance and expression of genes related to digestive enzymes, antioxidant capacity and immune system in rainbow trout (Oncorhynchus mykiss) for 60 days. 240 fish (initial weight 15.33 +/- 0.26 g) were randomly divided into 12 tanks (volume of 200 L, 20 fish per tank, in triplicates). Experimental diets were supplemented with 0 (C), 0.5 (PM05), 1 (PM1) and 2 (PM2) g kg(-1) pot marigold extract. Fish were fed ad libitum until the fish reached apparent satiation with nutritionally balanced diets (48% crude protein and 18% crude lipid) three times (08.00 am, 1.00 pm and 6.00 pm) daily. At the end of the study, the fish were individually weighed to measure growth parameters, including final weight (FW), weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), and feed conversion ratio (FCR). For gene expression analyses, the liver (antioxidant and non-specific immune parameters) and intestinal tissues (digestion) were sampled from fish (3 from each tank). Results showed that PM treatments had greater growth indices in comparison to the C group. (P < 0.05). The highest FW, WG, SGR and PER values were recorded in the PM1 treatment (P < 0.05). Similarly, the lowest, i.e. best FCR levels were obtained in the PM1 group (P < 0.05). Intestinal trypsin expression levels were significantly higher in the PM05 and PM1 treatments than in the C group, with the highest expression in the PM1 treatment (P < 0.05). Lipase expression reached the highest level in the PM1 treatment, while amylase was upregulated in all PM treatments compared to the C group (P < 0.05). Hepatic superoxide dismutase (SOD) expression levels were increased in the PM05 group, followed by PM1 and PM2 treatments (P < 0.05). Also, catalase (CAT) expression values were higher in the treatment groups than in the C group (P < 0.05). The glutathione peroxidase (GPX) expression level in the PM2 treatment was increased compared to the C group, while GPX in the PM05 and PM1 groups was significantly lower than in the C group (P < 0.05). Expression levels of interleukin-1 beta (IL-1 beta), tumour necrosis factor (TNF-alpha) and interleukin 8 (IL-8) genes relating to immunity exhibited overexpression in treatment groups compared to the C group. In conclusion, it can be concluded that diets supplemented with pot marigold extract, especially at 1 g kg(-1) level, can promote healthy growth for rainbow trout.
Effects of Chlorella Sp. and Schizochytrium Sp. Extracts on Growth Indices, Body Composition, and Gene Expression Profiles in Rainbow Trout ( Oncorhynchus Mykiss)
(Elsevier Science inc, 2025) Karatas, Boran
This study assessed the impact of dietary Chlorella sp. and Schizochytrium sp. extracts on growth performance, feed utilization, body composition, and gene expression related to growth, digestion, antioxidant defense, and immune response in rainbow trout (Oncorhynchus mykiss). A total of 180 fish (average weight 8.92 +/- 0.04 g) were randomly distributed into 12 fiberglass tanks (400 L, 15 fish per tank, three replicates per treatment). Fish were divided into four dietary groups for 60 days: 0 % (Control), 0.5 % Chlorella sp. extract (CH), 0.5 % Schizochytrium sp. extract (SC), and a combined 0.25 % Chlorella sp. and 0.25 % Schizochytrium sp. (CH + SC). At trial end, fish in the CH + SC group had a final weight (FW) of 27.06 +/- 0.28 g, significantly higher than other groups (P < 0.05), with improved growth parameters (P < 0.05). While body composition showed no differences in moisture, lipid, or ash content, crude protein was significantly higher in CH + SC (P < 0.05). Gene expression analysis showed upregulation of the growth hormone GH-I gene in the CH + SC group (P < 0.05). Genes related to digestive enzymes (trypsin, lipase, amylase) were also upregulated in all microalgae groups, with the highest levels in CH + SC (P < 0.05). Additionally, antioxidant genes (SOD, CAT, GPx) and immune-related genes (LYZII, TNF-alpha, IL-1 beta) showed elevated expression in CH + SC (P < 0.05). This study demonstrated that a diet containing Chlorella sp. and Schizochytrium sp. extracts supports growth, enhances nutrient utilization, and upregulates genes related to antioxidant and immune function in rainbow trout. Further research is recommended to assess functional immune responses and enzyme activities to confirm these physiological effects.
Effects of Different Led Light Spectra on Rainbow Trout (Oncorhynchus Mykiss): in Vivo Evaluation of the Antioxidant Status
(Springer, 2020) Guller, Ugur; Onalan, Sukru; Arabaci, Muhammed; Karatas, Boran; Yasar, Muhterem; Kufrevioglu, Omer Irfan
Rainbow trout (Oncorhynchus mykiss) farming is one of the major aquacultures in Turkey. Some conditions in fish farming can induce oxidative stress leading to the deterioration in properties such as appearance/color, texture, and flavor in fish meat. This situation may cause the consumer not to prefer edible fish. Although there are some studies on the impacts of light intensity on fish welfare, the changes in the antioxidant enzyme activities have not been elucidated. In the current study, it was intended to examine in rainbow trout how cultivating under different wavelengths affects the antioxidant enzymes and acetylcholine esterase (AChE) activity, because its activity is associated with oxidative stress, and also the determination of which light is suitable for fish welfare was aimed. Rainbow trout larvae were grown under four lights with different wavelengths: natural sunlight and incandescent long-wave (red light), medium-wave (green light), and short-wave (blue light) LED light. The experiment lasted for 64 days. Biochemical assays were carried on in the brain, gill, and liver of rainbow trout. Antioxidant enzymes and AChE activity, which play an important role in the central nervous system, were assayed. In gill tissues, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glucose 6 phosphate dehydrogenase (G6PD), glutathione reductase (GR), glutathione S-transferase (GST), and AChE activities increased under all three light wavelengths. In the liver, while activities of antioxidant enzymes and AChE decreased in red light, all of them increased in blue and green light. In the brain, GPx, GST, G6PD, and SOD activities were reduced but AChE activity did not alter under all three light sources. In conclusion, light sources with different spectral structures caused important changes in the activities of antioxidant enzymes in rainbow trout. On this basis, it may be thought that this may be a response to the changing redox status of a cell. Based on our results, blue light sources may be suggested for fish welfare in rainbow trout culture, and providing fish welfare by changing light sources can be easy and cheap in fish farming.
The Effects of Light Sources With Different Spectral Structures on Ocular Axial Length in Rainbow Trout (Oncorhynchus Mykiss)
(Academic Press Ltd- Elsevier Science Ltd, 2016) Timucin, Ozgur Bulent; Arabaci, Muhammed; Cuce, Ferhat; Karatas, Boran; Onalan, Sukru; Yasar, Muhterem; Karadag, M. Fatih
Every day, we are acquiring more and more clues regarding the effects of different spectral structures (SS) of light on ocular axial length (OAL). As a step towards understanding this association, this study sought to characterise the effects of light sources of different SS on OAL in fish through comparisons with indoor daylight. The experimental design was completely randomised with 4 treatments and 2 replications. Three hundred and fifty two rainbow trout (Oncorhynchus mykiss) were housed in 8 tanks and fed for 71 days. Differences in the mean values of ocular elongation were determined at the end of the experiment. The daylight group was exposed to indoor daylight in the hatchery environment, the red group was exposed to long wavelength light (600-650 nm), the green group was exposed to mid wavelength light (495-570 nm) and the blue group was exposed to short wavelength light (420-495 nm). The values of the OALs in fish grown under the same light intensity, but with light of different spectral characteristics, demonstrated significant differences (p < 0.05). The mean OAL in the daylight group was determined as 3.64 +/- 0.40 mm, as 3.70 +/- 0.35 mm in the red group, as 3.53 +/- 0.34 mm in the green group and as 3.42 +/- 0.29 mm in the blue group. The mean OAL in the blue group was significantly shorter compared to the red (p = 0.003) and the daylight groups (p = 0.02). When compared with the long wavelength light and indoor daylight, the effect of short wavelength light on OAL in fish was observed to be negative. Exposure to light with modified SS of in indoor environments may be effective in stopping ocular elongation. (C) 2016 Elsevier Ltd. All rights reserved.
The Effects of Light Sources With Different Spectral Structures on Ocular Axial Length in Rainbow Trout (Oncorhynchus Mykiss)
(Academic Press Ltd- Elsevier Science Ltd, 2023) Timucin, Ozgur Bulent; Arabaci, Muhammed; Cuce, Ferhat; Karatas, Boran; Onalan, Sukru; Yasar, Muhterem; Karadag, M. Fatih
Evaluation of Global Warming Effects on Juvenile Rainbow Trout: Focus on Immunohistochemistry and Osmoregulation
(Springer, 2025) Alkan, Zehra; Karatas, Boran; Sepil, Ahmet
The negative effects of global warming also directly affect aquatic populations. Consequences such as evaporation due to chronic temperature increase, increase in salinity, and increase in stock density per unit volume are potential stress factors. While creating the trial design, an attempt was made to simulate the effects of global warming, especially on species living in salty and brackish water biotopes. In this study, changes in the gills of rainbow trout (Oncorhynchus mykiss) acclimated to 0, 20, and 38 parts per thousand of saline in the laboratory were examined histologically and immunohistochemically and blood serum osmolarity. In addition, the water temperature was changed, and experiments were carried out at 16, 19, and 22 degrees C for each salinity group in parallel with the increase in salinity. However, to simulate the decrease in water volume and intensive stocking due to the potential impact of climate change, the study was carried out using 15 fishes in low-volume aquariums (45 L). Tap water that had been kept for at least 3 days was used in the aquariums. To protect the water quality, independent aquariums with sponge filters were used, and since the aim was to keep dissolved oxygen low, no ventilation system other than the sponge filter was used. In order to minimize the deterioration in water quality during the trial, a 15% water change was performed by performing a bottom flush every 4 days and water of the same temperature and salinity was added as much as the reduced volume. In addition, since increasing stock density due to temperature increase and water decrease will cause the amount of dissolved oxygen to decrease, pure oxygen was not entered into any tank throughout the experiment, and the concentration was requested to be at a low level (7 +/- 0.13 mg/L) in all groups. The trials were terminated at the end of the 71st day. Increased serum osmolarity values were observed due to the increase in salinity, and the highest serum osmolarity value was measured at 644 mOsm/kg in the 38 parts per thousand salinity group. Differences between the groups were found to be statistically significant (p < 0.05). It was observed that the number of cells containing Na+/K+-ATPase increased depending on salinity. Also, the number of chloride cells reached the maximum level in the 38 parts per thousand salinity group. Due to increasing salt levels, an increase in mucus cells, limited onset hyperplasia, aneurysm, lamellar separation, and necrosis were observed in the gill tissue.
Impact of Dietary Gallic Acid on Growth Indices and the Expression of Antioxidant, Stress, and Immunity-Related Genes in Rainbow Trout (Oncorhynchus Mykiss)
(Ege Univ, Fac Fisheries, 2025) Karatas, Boran
This study investigates the effects of dietary gallic acid (GA) supplementation on growth performance and the expression of genes linked to antioxidant, stress, and immune functions in rainbow trout (Oncorhynchus mykiss). Fish with an average body weight of 2.84 +/- 0.25 g were fed diets containing 0 mg/kg (control), 300 mg/kg (G300), 450 mg/kg (G450), and 600 mg/kg (G600) of GA over 60 days. The results revealed significant improvements in growth indices, including weight gain, specific growth rate, and feed conversion ratio, in GA-supplemented groups compared to the control (P<0.05). At the molecular level, GA supplementation significantly upregulated the expression of antioxidant-related genes (SOD, CAT, GPX), stress-related genes (HSP70), and immune-related genes (TNF-alpha, IL-1 beta). The G300 group consistently exhibited the most pronounced transcriptional responses, while higher doses (G450 and G600) showed diminished or inconsistent effects. These findings suggest that a dietary inclusion of 300 mg/kg GA optimally enhances fish health and productivity by modulating key molecular pathways. This dosage is recommended as an effective feed additive for improving the performance and resilience of rainbow trout in aquaculture.