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Rainbow trout, Oncorhynchus mykiss (mean weight 70.8±1.0 g SEM) raised in the Sea of Marmara (Turkey), were used for a preliminary gastric evacuation study. After being starved 72 hours, three groups of 110 fish, each, were fed ad libitum once, twice or three times in a single day. Ten fish from each group were withdrawn and killed in an anesthetic solution during each sampling at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 hours following the last feeding. Gastric material was removed from the fish and dried for gastric evacuation modelling. Gompertz and logistic models (with fixed asymptotes) best explained the data. The gastric emptying rate of the trout offered a single meal (Group A) was faster than those fed two (Group B) or three (Group C) meals while the emptying patterns of Groups B and C were similar to each other. The time required to evacuate 95% of the gastric material from the first meal was estimated as 54.3, 68.0 and 67.8 h for Groups A, B and C, respectively, accordin...

The significance and protection of the biological diversity in the continental waters of countries in the world has become one of the concerns which should be addressed as a matter of urgency. The scientists consistently underline the fact that several species are endangered to extinct and that the number and population of such species are gradually decreasing. There observed many causes of the extinction of the species. The heavily increase of the human population is the most important reason for this. Such a heavy increase leads to establishment of new settlement areas and constriction of the wild life. In this case, the number of wild species extinct rapidly. Several scientists and members of the nature protection organizations are aware of this particular case and conduct studies to protect the natural environment of the wild life. In this context, the wild life should be given the chance to reproduce through formation of the national parks and natural protection zones. Such par...

E.Ü. Su Ürünleri Dergisi 2002 EU Journal of Fisheries & Aquatic Sciences 2002 Cilt/Volume 19, Sayı/Issue (3-4): 539 – 544 ... © Ege University Press ISSN 1300 - 1590 http://jfas.ege.edu .tr/ ... Dere Alabalığının (Salmo trutta fario Linnaeus, 1758) Deniz Suyunda Yetiştiriciliği

WOS: 000388312400006Natural fish stocks could be at risk due to interbreeding or competition with farmed fish, which often differ genetically from their counterparts in wild. Farming of sterile or all-female triploids could be a powerfull preventative measure for preservation of natural gene resources or biodiversity of native species. Although, techniques for ploidy are well described in many fish species, there is no report whether the previous techniques applicable in out-off-season production induced by artificial photoperiod that is widely used in salmonid aquaculture. In order to optimize and refund ploidization protocol for off-season production of diploid gynogenomes and triploids three experiments were conducted to determine the optimal UV inactivation of sperm and heat shock treatment of eggs in rainbow trout (Oncorhynchus mykiss). High survival at yolk sac absorption stage (82.3-84.5%) and high yields (approx. 100%) were achieved from the range of treatments applied. Ther...

Three diets including 13.2%, 22% or 30.5% carbohydrates as extruded wheat meal were fed to rainbow trout, Oncorhynchus mykiss (initial weight 34.8 g), for twelve weeks to investigate their influence on growth, protein and energy utilization and carcass composition. Daily feeding rates were 1.76, 2.05 or 2.17 g feed per 100 g body weight for the three diets, respectively, so as to reach a daily allowance of about 35.5 kJ digestible energy per 100 g body weight. No significant differences (p>0.05) in final mean weight or specific growth rate were observed between the treatments. Feed efficiency was negatively correlated to the dietary carbohydrate level. Utilized digestible protein and energy per kg growth were 365, 348, 358 g and 15.4, 15.9, 17.0 MJ, respectively, for the three diets. Apparent net protein and energy utilization of the groups fed a medium or high carbohydrate level were higher than those of the low carbohydrate group. Analysis of fish carcasses at the end of the tr...

Spawning of the common pandora (Pagellus erythrinus L.) in captivity was studied at ambient temperature (21.2±1.2°C) during the breeding season in 1998. Broodstock were cultivated in net fishpens and spawned in large fiberglass tanks (10 m diameter) between June and July. Approximately 33.2 million eggs were collected from 30 mature 4-7 year old females, 97% of which were buoyant healthy eggs with diameters ranging 753-801 μm. The eggs were incubat- ed at 19, 21, or 23°C and development and morphological changes were observed until day 50. The best hatching rate (88.9%) was obtained at 19°C. Swim bladder inflation occurred 8-20 days after hatching. The average survival at day 50, at an initial density of 40 larvae/l, was 3.2%. Exogenous feeding began on day 3. Larvae were first fed rotifers, Brachionus plicatilis, and later Artemia nauplii. Larvae completed yolk absorption 78 hours after hatching. A green water envi- ronment was maintained by introducing cultured microalgae (Nannoch...

Bu çalışmada, deniz suyuna doğrudan transfer edilen gökkuşağı alabalıklarının (yaklaşık 285 gr) büyüme performansları ve yaşama oranları yüzer alabalık işletmesinde yaz boyunca 90 gün takip edilmiştir. Çalışma sonunda gökkuşağı alabalıkları 285 – 289 gr canlı ağırlıktan 667.3 – 675.8 gr’a ulaşmışlardır. Yem değerlendirme katsayısı 1.129 – 1.136 olarak, mortalite ise %6.07 – 7.19 oranında saptanmıştır. Sonuç olarak, yüzer alabalık işletmesinde elde edilen verilerin önceki çalışmalarla kıyaslandığında makul sonuçlar olduğu görülmüştür. Teknik ve idari sorunlar çözülebildiği takdirde, yüzer alabalık işletmesi açık deniz balık yetiştiriciliği açısından günümüzde önemli bir fırsat olabilir.In this study, growing performance, food conversion ratio and survival of rainbow trout (around 285 g) which were transferred to seawater for directly was investigated in the mobile fish farm during summer season for 90 days. At the end of study, rainbow trouts reached from weighing 285 – 289 g to 667.3 – 675.8 g. FCR were around 1.129 – 1.136. Mortality occurred around 6.07 – 7.19%. As a result, growth performance and survival of rainbow trout in the mobile fish farm was considerably well when comparing with previous studies. Mobile fish farm can be an important opportunity nowadays for off-shore aquaculture, if technical and administrative problems could be solved

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.

This study is the first spawning and larval rearing of the F1 hybrid striped bass (Morone chrysops ♀ X M. saxatilis ♂) grown in culture conditions in Turkey. The F1 Hybrid striped bass was fed with commercial pellet feed in floating net cages. They reached the sexual maturity at two years old. Female brood fish were given 30 µg/kg of LHRH-a (Lutenizing hormone releasing hormone analogue) and male fish given 10 µg/kg; of CHP(Dried carp pituitary), 4 mg/kg was used for the female and half that amount for the male for induced breeding. The fish injected LHRHa were successfully induced to both strip spawning and tank spawning by a single hormone injection. However, fish injected CPH and saline, untreated control did not spawn. Latency period was found to be 20.41±0.91 hour. In term of fertilization rate, larval deformity rate no significant difference was found between tank spawning and strip spawning (p>0.05).Fertilization rates ranged from 56.3% to 85.4% and hatch rates were between 0.99% and 46.88%, whereas the level of larval deformities ranged between 81.25% and 100%. Hatched larvae were placed into 400-liter rectangular tanks with water discharge of 4 liter/minute at a stocking density of 30 larvae/liter. After larvae hatching, they were given artemia nauplii for 5-19 days. Trout granule feed (300-500 micron) also started to be given in addition to artemia nauplii afterwards. Granule feed was started eating completely 24 th days. The larvae obtained from a single hatch in the production season reached 2.87 cm length in 32 days with 2.7% survival rate. Of this study was terminated due to white spot disease (Ichtyophthirius multifilis) arising from sudden change in water temperature. The F2 progenies were not deemed to be available for aquaculture due to poor fertilization, poor hatching, low survival rate and high deformity rate. For the progenies of the hybrid striped bass that grow in natural water, it was suggested that their ecology in waters in Turkey be first studied and brought into aquaculture afterwards.

Keywords:Tilapia, reproduction, aquaculture, aquaponics. ABSTRACT In 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. In 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.

Anesthetics are used for performing basic procedures such as weighing, tagging, experimental work, harvesting, spawning procedures and during transportation to prevent physical injury and reduce metabolism in aquaculture. Using of natural plant materials such as clove oil (eugenol) for sedation of fish becomes more important in aquaculture industry. In this experiment, different concentrations of clove oil (20, 30 and 40 ppm) were applied on broodstock of brown trout (Salmo trutta fario) and rainbow trout (Oncorhynchus mykiss) of different genders. Times to induction and recovery from anesthesia were measured. No fish died during trials. Induction times of anesthesia varied with clove oil concentrations, decreasing with the increase of clove oil concentrations. On the other hand, recovery times increased with decreasing of clove oil concentrations only on male trouts. The induction times for fish exposed to 20 ppm clove oil were generally longer compared to 30 and 40 ppm (p<0.05). Dose of 30 ppm clove oil produced rapid anesthesia with shorter recovery for females in both of species. On the other hand, the shorter recovery times were recorded for males in both species at 20 ppm. According to our results, recovery times were more gender-dependent for adult rainbow and brown trouts (p<0.05). Recovery times were shorter in adult females than males, especially for 30 and 40 ppm clove oil, while male brown trouts were induced longest times in these dosages (p<0.05). It can be said that as an environmental friendly substance clove oil with optimal dose of 30 ppm can be administered for anesthesia safely in both of adult male and female trouts.

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