Publications

In this study, the effects of 17-ß-estradiol hormone on the zootechnic performances and sex ratio of Mozambique Tilapia (Oreochromis mossambicus. Peters, 1852) fry were investigated in order to initially produce functional phenotypical females and then super males. To this end, different E2 concentrations (50, 100, 150 and 200 ppm) were tested over a period of 45 days in a closed recirculating system. The evaluations showed that the female ratio was significantly (p value= 0.04 and α=0.05) higher in all treatment groups ranging from 61.90% to 86.36% compared to the control group. Growth was significantly higher (F value=22.78 and p value=0.00) in the control group compared to the treatment ones.

In this study, certain water quality parameters (water temperature, dissolved oxygen (DO), pH, total inorganic nitrogen (TIN), phosphate (PO4), nitrite (NO2), nitrate (NO3), ammonium (NH4), and (BOD5) in the effluents and the efficiency of the treatment systems for eliminating wastes at a commercial trout farm with a capacity of 10 tons/year in Izmir (Kemalpasa) were examined. The DO, temperature, pH, TIN, PO4, NO2, NO3, and BOD5 measured, were different in the outlet waters when compared with the inlet waters (p<0.05). The settling basin did not reduce the TIN and PO4, on the contrary, it caused an increase in the nitrogen (N) up to 19.9% and phosphorus (P) up to 20.30%, while the wetlands reduced the N, P, and BOD 5 up to 53.2%, 58.2%, and 36.5%, respectively (p<0.05). According to the chemical and biological methods, the averages of the TIN and P loads for one tone of cultured trout without treatment were estimated to be were 80 kg and 7 kg, respectively. The annual TIN load of this trout farm was estimated to be 21.3 kg while the TP load was 2.9 kg for one tone of cultured trout when the treatment efficiency was taken into account. The microbiological analyses conducted with the effluent waters showed that the rate of aerobic mesophilic bacteria was found to be high in the summer but low in the winter. It was also detected that the coliform group bacteria were present in the environment in the summer while their occurence was with-in standards in the winter. Interactions of the 9 water quality parameters were identified through the linear regression analysis in order to reduce the environmental effects of the facility DO= 28.296 – (0.248 × BOD 5 ) – (2.948 × pH) + (0.189 × temperature) + (0.851 × inlet water) + (0.163 × winter) (R2=0.912). According to this model, the DO values were increased by the temperature, inlet water and the winter season while reduced by the BOD5 and pH. The dissolved oxygen content in the wetland outlet water was measured as being high because of the nutrient and temperature rises which boosted photosyntesis. It was concluded that using mechanical settling methods were inadequate to minimise the nutrients released into the receiving water body so wetlands should be constructed in such a way as to receive the flow of effluents from the trout farms. As a result the quality of water used by the facility has no adverse impact on the aquaculture and environmental ecosystem.

The development of deformities in farmed fish is largely the result of abiotic, biotic, and xenobiotic factors, information deficiencies in optimizing nutrition, and the genetic background to which the fish are exposed in their early life stages. In general, skeletal anomalies are considered to have significant adverse effects on animal welfare, biological performance of farmed fish, product quality, and production costs. In the data obtained by the meta-analysis method, the presence of negative effects on the formal structures of fish was found, regardless of the region, duration, stage, factor, stock density, and method used to detect deformation. In this regard, in the studies considered within the deformation region/type, 46% of deformities were found in the spine, 37% in the head, and 16% in the total skeleton. In turn, the results of the meta-analysis showed that the percentages of the apparent value were 35.82% in the spine, 33.12% in the skeleton, and 31.06% in the head. The deformation rate had an overall negative effect on the functional characteristics of the fish, regardless of the variables considered. In addition, all statistically significant individual response variables had a negative effect size. In the future, advanced statistical tools such as Bayesian meta-analysis, network meta-analysis, and meta-regression analysis can be used to explore more complex data structures. The rapid development of artificial intelligence techniques will increase the efficiency of data collection and the robustness of results for meta-analysis studies in aquaculture and other fields.

Common dentex (Dentex dentex) is a commercial species of fish that is a highly valuable food source living naturally near Mediterranean and Atlantic Coasts. Therefore, monitoring and maintaining common dentex habitats are of high importance. A total of 53 specimens were collected from 6 natural habitats (from the Eastern Aegean and from the Antalya coast, which is the closest coast to the Western Mediterranean), and one aquaculture facility in the Eastern Aegean Sea. The mitochondrial Cytochrome Oxidase I (COI) gene was used to detect a total of 26 haplotypes. Along with the COI gene sequence, real-time PCR and highresolution melting analyses were performed as rapid and inexpensive alternatives. Sequence analysis showed that the highest haplotype diversity was obtained from the aquaculture facility in Karaburun and Antalya Locations, Turkey. Analysis of Molecular Variance (AMOVA) based on the haplotype frequencies resulted in 92.54% genetic variation within localities and 7.46% genetic variation between/among localities. The mean fixation index (Fst) was calculated as 0.0746 (p &lt; 0.001). Genetic distances were primarily in collaboration with geographical distances and were efficiently confirmed by high resolution melting (HRM) analysis. The results will be valuable in monitoring and maintaining natural habitats as well as aquaculture facilities where common dentex are grown.

Keywords:Axillary Seabream, Pagellus acarne, sea water cages, sea cage culture, aquaculture, growth, feeding. ABSTRACT The purpose of this study was to obtain some preliminary data on acclimation of fingerlings and grow-out of Axillary Seabream (Pagellus acarne Risso, 1926) under intensive conditions in sea net cages. In this study, Axillary Seabream (Pagellus acarne) juveniles were caught from Sigacik/Seferihisar and stocked in the sea water net cages. Fish were reared for 13 months with commercial fish feed. The size of the net cages that were used in the experiment, ranges from 5 x 5 x 5 and 10 x 10 x 9 m3, depending of the fish size. Initial mean weight of fish, stocked in cages, was 31,52 ± 1,73 g. Final mean weight was obtained 277,16 ± 6,75 g. The survival rate of the fish during the experiment until marketing size was >95% . The feed conversion ratio (FCR) was calculated as 3,3.

Abstract The development of deformities in farmed fish is largely the result of abiotic, biotic, and xenobiotic factors, information deficiencies in optimizing nutrition, and the genetic background to which the fish are exposed in their early life stages. In general, skeletal anomalies are considered to have significant adverse effects on animal welfare, biological performance of farmed fish, product quality and production costs. In the data obtained by the meta-analysis method, the presence of negative effects on the formal structures of fish was found, regardless of the region, duration, stage, factor, stock density, and method used to detect deformation. In this regard, in the studies considered within the deformation region/type, 46% of deformities were found in the spine, 37% in the head, and 16% in the total skeleton. In turn, the results of the meta-analysis showed that the percentages of the apparent value were 35.82% in the spine, 33.12% in the skeleton, and 31.06% in the head. The deformation rate had an overall negative effect on the functional characteristics of the fish, regardless of the variables considered. In addition, all statistically significant individual response variables had a negative effect size. In the future, advanced statistical tools such as Bayesian meta-analysis, network meta-analysis, and meta-regression analysis can be used to explore more complex data structures. The rapid development of artificial intelligence techniques will increase the efficiency of data collection and the robustness of results for meta-analysis studies in aquaculture and other fields.

Küreselleşmenin hızlandığı günümüzde su ürünleri sektörünün özellikle su ürünleri işletmelerinden Alabalık işletmelerinin önemi gün geçtikçe artmaktadır. Bu araştırmada Tarım, Gıda ve Hayvancılık Bakanlığı kayıtlarından alınan Türkiye’deki alabalık işletme adresleri kullanılmıştır. Bu alabalık tesislerine Delphi anket yöntemi uygulanmıştır. Anket sonuçlarında elde edilen uzman görüşlerine göre Türkiye’ de alabalık yetiştiriciliğinin sorunlarını çözümlenmesi ve gelişmesine yönelik yapılması gerekenler şunlardır; İşletme açmak, üretimde devamlılığı sağlamak ve üretilen malı pazara sürmek için gerekli olan bürokratik formaliteler azaltılmalıdır. Üretimin kaliteli ve yüksek verimde yapılabilmesi için hastalıktan ari yavru ve yumurta üretimi teşvik edilmelidir. Yem fiyatları yüksektir. Bu nedenle yem kalitesi düşürülmeden fiyatlarda indirime gidilmelidir. Alınan vergilerin azaltılması bu sorunun çözümünde iyi bir adım olabilir. İşletmelerin kredi gereksinimlerinin giderilmesine yönelik kredi sağlayan kuruluşların işletmelerin mevcut durumlarını dikkate alarak alternatif şartlar geliştirmesi yarar sağlayacaktır. Gerek işletmelerin kuruluş aşamasında, gerekse üretim aşamasında ilgili kurumlarca işletmelere yeterli düzeyde teşvik sağlanmalıdır. İşletmelerde genel olarak karşılaşılan sorunların çözümünde kooperatifleşmeye gidilmesi şarttır. Sonuç olarak, Türkiye’nin çeşitli bölgelerinde alabalık yetiştiriciliği sektörü içinde aktif olarak çalışan uzmanların ortaklaşa belirledikleri sorunların uygun bir biçimde çözümlenmesiyle, sektörün ülkemizde gerek ekonomik gerek bilimsel olarak ilerleme kaydedeceği açıkça görülmektedir

This study examined the growth performance of bristlenose pleco (Ancistrus multispinis) fry raised at five different stocking densities. For this purpose, five experimental groups were formed, each consisting of three replicates: 1 fry/L (d1), 2 fry/L (d2), 4 fry/L (d4), 6 fry/L (d6), and 8 fry/L (d8). The experiment used fry produced in the laboratory, with average initial live weights of 0.0275 ± 0.004 g and average total lengths of 1.46 ± 0.049 cm. The study lasted a total of 90 days. At the end of the experiment, the number of live fry in each group was recorded, and weight and length measurements were taken. According to these measure-ments, the average length of the fry in the 1 fry/L group (d1) was 3.1 cm, and the average weight was 0.321 g, while in the 8 fry/L group (d8), the length was found to be 2.8 cm, and the weight was 0.249 g. The size differences between groups were examined, and it was found that the d1 group showed statistically signifi-cant differences when compared to the other groups. The data obtained indicate that fry of A. multispinis grew more in lower stocking densities, such as 1 fry/L, compared to other groups. Based on these results, it can be said that utilizing lower stocking densities, such as 1 fry/L, is advantageous in the growth of A. multis-pinis fry.

Abstract: Aquaculture is one of the world’s fastest-developing and growing food-producing sectors. The subsector’s expansion commenced in the 1970’s, actuated by move forwards in hatchery technology and pond husbandry. Aquaculture and especially fish farming, however, have been discussed as negative potential effects on environment. The negative potential effects are, direct mortality, loss of biodiversity, tainting of wild species. Moreover these are disease transmission to other species, displacement of wild fish from natural habitat.Although these negative potential effects, cultural fish represent genetically exogenous populations or crosses between them. Some pauper gen pool of cultured fish population can develop with fertile gen pool of natural fish population or just the opposite of them.It can be said that cultured fish typically constitute gene pools. We need an observation which brings an urgent focus for conservation between natural populations and spawning populations. In this review it was observed negative genetic impacts of escaped farmed fish population on wild fish population by mtDNA markers.Keywords: Genetic impact, escaped farmed fish, molecular markers, mtDNA markers

The present study was planned with the aim of inactivating the total bacterial load and species in tilapia fish tanks kept in fresh and seawater conditions with high stock density with different UV lamp models. In this context, the UVC+UVA-Led lamp system was compared with the conventional UVC lamp system and the total bacterial load in the tanks and the inactivation effect on the bacterial species were determined. Total bacterial load on the medium and bacteria species were identified in terms of their morphological characteristics using the spread plate method. Bacteria that emerged at different times in the trial sets were identified as Edwardsiella tarda, Salmonella sp., Aeromonas hydrophila, Pantoea sp., Citrobacter youngae, Serratia ficaria and Citrobacter freundii. The total bacterial load in both freshwater and seawater environments in both lamp groups showed a decrease compared to the control group. With this, the conventional lamp model was more effective on the total bacterial load in the samples taken during the trial. Although all bacteria were inactive in both lamp groups, Serratia ficaria bacteria were not eliminated in the seawater environment. The results show that UV LEDs can be a better alternative to traditional UV mercury lamps for water disinfection.

Keywords:Tilapia, reproduction, aquaculture, aquaponics.&#13;\nABSTRACT&#13;\nIn order to close the food gap resulting from population growth, cheaper and more quality producible species gain importance in the world. Since tilapia has a lot of positive characteristics desired for culture, they are among the significant species and have a rising value. Tilapia is known to have about 100 species and its culture began in Africa and spread to many other countries. There may be some problems in tilapia culture including the tropical regions to which they are indigenous. Tilapia species are not found in Turkey’s natural waters but studies towards their culture began in 1970s. Although a lot of scientific research has been conducted, required levels have not been reached yet.&#13;\nIn this study, information regarding the general characteristics of tilapia, reproduction biology, production techniques, and problems in aquaculture and their use in aquaponic system has been presented.

In this study, the effects of water temperature on growth, survival rate, gonad development and sex ratios of Mozambique Tilapia (Oreochromis mossambicus) were studied by applying different temperature applications (28, 30, 32, 34 and 36oC) for a single period of 40 days. At the end of the study, in the control group (28oC), the males proportion was 47.62%. In fishes reared at 30oC, average male ratio was found as 73.68%. The highest male proportion was obtained in the 36oC temperature group (86.67%). Growth performances, feed utilization and gonad development were found to increase with elevating temperatures up to 34oC unlike the survival rate which has been found to fall with higher temperatures. In this study, sex differentiation rates differed significantly between all groups (p&amp;lt;0.05). However, the highest male rate obtained in group A and D. As hypothesized, results suggest that fish performed better at 30-32°C than 28°C or 34-36°C water temperature and the optimum temperature for a better expression of growth parameters in Mozambique Tilapia could be 30oC.