Effects of synthetic androgen (17α-methyltestosterone) and estrogen (17β-estradiol) on growth and skin coloration in emperor red cichlid, Aulonocara nyassae (Actinopterygii: Cichliformes: Cichlidae)

In recent years, the use of anabolic steroids in the coloration and growth of fishes, especially ornamental ones, has attracted great interest. In the ornamental fish industry, it is economically advantageous to produce some species with high commercial value and higher demand, depending on size, color, and sex. Therefore, the most commonly used steroids in this study—i.e., 17α-MT and 17β-Es (E2)—were added to the diet of emperor red cichlid, Aulonocara nyassae Regan, 1922, which has not been previously hormone-treated and has high economic value amongst ornamental fishes. A 60-day study was conducted in a closed system, where the juveniles of the emperor red cichlid were acclimatized with the control/basal diet for 15 days. After which, 15 fish with a similar shade of color and about 5 months old were weighed individually (0.71 ± 0.01 g). All fish were placed into aquaria (30 L) in five different groups, in triplicate. Five different groups consisted of control (without hormone), 50 mg · kg–1 17α-MT, 100 mg · kg–1 17α-MT, 50 mg · kg–1 E2, and 100 mg · kg–1 E2. The fish were fed a diet twice a day (10:00 h, 17:00 h) for 60 days till satiation. During the entire trial period, a 12 h light–12 h dark photoperiod was maintained. Water temperature was measured daily and recorded. Growth parameters of experimental fish were calculated. The color measurement of fish skin (L*, a*, b* values) from around the dorsal section was performed using a colorimeter (Konica Minolta CR 400). Significant differences were determined in the following parameters: weight gain (WG), specific growth rate (SGR), feed conversion rate (FCR), survival rate (SR), condition factor (CF), and sex reversal. The fish group fed with 17α-MT displayed brighter coloration as compared to other groups. Color analysis (instrumental) in terms of L*, a*, and b*, values showed that the group fed with 17α-MT displayed brighter coloration compared to other groups (P < 0.05). In terms of sex reversal, the fish in the 17α-MT groups exhibited 100% masculinization, whereas in E2 supplemented fish groups (50 and 100 mg · kg–1), the feminization rates were 88.88% and 93.33%, respectively. In conclusion, both hormones were found to have positive and negative effects for this fish species, but the 17α-MT hormone was found to be more effective in reversing skin pigmentation, growth, and sexing, which is the main driver in the ornamental fish trade

Effects Of Dietary Carotenoids On Broodstock Performance and Egg Quality; A Rewiew

Damızlık yem formülasyonu hazırlanması balık yetiştiricilerinin ve yem fabrikalarının en temel görevlerinden birisidir. Yetiştiriciliği yapılan balık türleri için yem yapım teknolojisi, yem karışımına giren maddeler ve yem/yemleme araştırmaları çok önemlidir. Damızlıkların yumurta üretimini etkileyen yem içeriğindeki maddelere özellikle yağ asidi, vitamin, probiotik, antioksidant ve karotenoidler üzerine araştırmacılar ağırlık vermektedirler. Doğadaki alabalıkların kas, deri ve yumurtalarındaki kırmızı-portakal rengi karotenoidlerden kaynaklanmaktadır. Karotenoidler genelde pazara sunulmadan önceki belli bir periyotta balık yemlerine belirli konsantrasyonlarda katılan yemlerle besleme yaparak balıkların pigmentasyonu için kullanılmaktadır. Karotenoidlerin yumurta rengine göre yumurtanın kalitesini ve yumurta sayısını pozitif yönde etkilediğini ve karotenoid konsantrasyonu ile yumurtadan çıkış yüzdesi arasında pozitif korelasyon olduğunu belirten birçok hipotezin var olduğu bilinmektedir. Bu nedenle derlemede, karotenoid içeren yemlerin damızlıkların yumurta üretimi ve kalitesi üzerine ilişkisi incelenerek açıklığa kavuşturulmaya çalışılmıştır.Broodstock diet formulations are essential duty for fish farmers and commercial diet manufacturer. The investigations on feed ingredients and feed development are important for aquaculture species. Many researchers aim on diet ingredients especially fatty acids, vitamins, probiotics, antioxidant and carotenoids on egg production of salmon broodstocks. The red-orange colour muscle, skin and eggs of wild salmonids are related to carotenoids. Generally, The carotenoids are utilized as supplementation diets for pigmentation of trout before markets. There are several hypotheses proposing that carotenoids positively affect the quality and the number of egg reproduced and a positive correlation between carotenoid concentration and hatching percentage The present rewiew discusses these studies and focuses on the more recent work on egg production and quality with the aim of understanding the specific dietar y carotenoids of trout broodstocks

Investigation of Ammonium Saturation and Desorption Conditions of Clinoptilolite Type Zeolite in Aquarium Conditions

In this research, it was aimed to determine the adsorption, saturation reaching and desorption effects of ammonium, which is one of the parameters that should be kept in control for aquarium life, by clinoptilolite type zeolite which is a natural filtration material. In the aquarium water, Z1: 20 mg/l TAN and Z2: 40 mg/l TAN concentrations were determined to have adsorption up to Z1: 10 mg/l TAN and Z2: 24 mg/l TAN concentration at the end of the experiment period. After this phase, where zeolites had reached saturation, desorption system was created, and 2 groups were formed with 5-liter research aquariums and 3 repetitions. During the five-days test, water parameters were determined daily and at the same time of day (10.00). At the beginning of the experiment, mean values of 0.4 ± 0.00 mg / l TAN in Z1 and Z2 groups were determined at the end of the experiment as 1.55 ± 0.176 mg/l (15.5%) and 2.153 ± 0.27 mg/l (13.5%) TAN in Z1 and Z2 groups, respectively. When the data obtained in this study were evaluated, zeolite was determined to make desorption periodically in proportion with the amount of retained ammonium, when it reached the saturation. In intensive aquaculture systems or aquarium conditions, recondition of zeolite for necessary periods is recommended to be performed by considering these data

Effects of Diets Containing of Brown Fish Meal and White Fish Meal on Growth of Rainbow Trout, Oncorhynchus mykiss (WALBAUM, 1792) Juveniles

Bu çalışmada, alabalık yemlerinde kullanılan kahverengi (hamsi, Engraulisencrasicolus L.) ve beyz balık unu (morina, Gadus morhua L.), gökkuşağı alabalığı yavrularının büyüme performansı , yem ve protein değerlendirme, nitrojen birikim ve nitrojen başaltım miktarı üzerine etkisi araştırılmıştır. Denemede kullanılan yemler iso nitrojenik (460 g kg-1) ve iso lipidik (200 g kg-1) olacak şekilde formüle edilmiştir. Üç tekerrür olarak planlanan denemede ortalama ağırlığı 10 g olan 120 adet yavru balık kullanılmıştır. Balıklar 30 gün süreyle günde iki kez doyuncaya kadar yemlenmişlerdir. Deneme sonunda en iyi spesifik büyüme oranı, yem değerlendirme sayısı, protein dönüşüm randımanı, nitrojen birikim ve boşaltım miktarı beyaz balık unu içeren yemle beslenen gruptan elde edilmiş ve gruplar arasındaki fark önemli (p<0,05) bulunmuştur

Determination of calpastatin (CAST) gene polimorphism in some native sheep breeds reared in Turkey by PCR-RFLP method

Bu çalışmada, Türkiye’de yetiştirilen 7 yerli koyun ırkında kalpastatin (CAST) gen polimorfzmi PCR-RFLP metodu kullanılarak araştırılmıştır. CAST geninin M ve N allelleri frekansları; Kangal (n= 31), İvesi (n= 26), Güney Karaman (n= 23), Akkaraman (n= 21), Morkaraman (n= 34), Karayaka (n= 33) ve Karakaş (n= 22) koyun ırklarında sırasıyla 0.92- 0.08, 0.59-0.41, 0.67-0.33, 0.69-0.31, 0.87-0.13, 0.86-0.14, 0.89-0.11 olarak tespit edilmiştir. Ki-kare testi CAST geni bakımından Morkaraman, İvesi ve Karayaka populasyonlarının Hardy-Weinberg dengesinden önemli düzeyde (P<0.05) saptığını, diğer populasyonların ise Hardy-Weinberg dengesinde olduğunu göstermiştir.In this study, calpastatin (CAST) gene polimorphism was investigated in 7 native sheep breeds reared in Turkey by using PCR-RFLP method. The frequencies of M and N alleles of CAST gene in Kangal (n= 31), Awassi (n= 26), G&uuml;ney Karaman (n= 23), Akkaraman (n= 21), Morkaraman (n= 34), Karayaka (n= 33), and Karakas (n= 22) sheep breeds were determined as 0.92-0.08, 0.59-0.41, 0.67-0.33, 0.69-0.31, 0.87-0.13, 0.86-0.14, 0.89-0.11 respectively. According to chi-square test, all the other populations were consistent with Hardy-Weinberg equilibrium, whereas Morkaraman, İvesi and Karayaka populations showed signifcant (P&lt;0.05) deviation from Hardy-Weinberg equilibrium for the CAST gene

Growth Performance and Feed Utilization of Koi Carp (Cyprinus carpio L., 1758) Fed Partial or Total Replacement of Fish Meal with Hazelnut Meal and Soybean Meal

The effects of soybean and hazelnut meals as partial and total replacements of fish meal were studied on the growth performance and feed utilization of Koi carp juvenile (Cyprinus carpio L., 1758). Juvenile fish (mean initial weights 0.12 g) were fed five isonitrogenously (350 g kg‾1) and isocalorically (4.20 kcal g‾1) diets with 50 or 100% of the fish meal protein replaced by soybean and hazelnuts protein. The control diet contained fish meal as major protein source. A total of 225 juvenile koi were randomly assigned to each treatment which was replicated three times with 15 fish each. The fish were fed with these diets for 65 days. The results showed that Final Body Weight (FBW), Relative Growth Rate (RGR) and Protein Efficiency Rate (PER) were not significantly different among groups. Fish fed control, 50% SM, 50% HM and 100% SM diets had similar Specific Growth Rate (SGW) values while fish fed the 100% HM diet had lower SGR values than those of other diets (p<0.05). The FCR values of fish fed 50% SM and 50% HM diets were significantly different than that of 100% HM (p<0.05). The highest FCR was obtained from 50% HM diet. The results indicated that koi carp juvenile can be cultivated with feeding diets containing 50% SM, 100% SM and 50% HM without any adverse effect on growth performance of fish

Effects of Dietborne Copper on Accumulation in the Tissues and Organs, Growth and Feed Utilization of Rainbow Trout (Oncorhynchus mykiss, Walbaum, 1792) Juvenile

The present experiment was conducted to study effects of elevated dietary Cu and establish upper limits of Cu in fish feed. Accumulation and growth of dietborne copper in the gill, muscle tissue, digestive system and whole body of rainbow trout (Oncorhynchus mykiss, Walbaum). Four experimental isonitrogenic (460 g kg-1) and isolipidic (200 g kg-1) diets were formulated. Diets were prepared by adding 0 (control), 0.1, 0.4 or 1.6 g kg-1 CuSO4.5H2O feed, respectively. Each diet was randomly assigned to triplicate groups of 576 juvenile fish whose average weight 19.97±0.048 g. Fish were fed to satiation for experimental period. After 15, 30, 45 and 60 days, the fish were sampled and Cu accumulation in the gill, muscle tissue and the digestive system were determined. The data were presented in μg of sample Dry Weight (DW). At the end of the trial, with increasing dietary Cu concentration, Cu accumulation of gill, muscle tissue, liver and the digestive system were increased. However, accumulation of gill were not significant (p>0.05) in the fish fed with 0.4 (D 3) and 1.6 (D 4) g kg-1 CuSO4.5H2O diets. Accumulation of muscle tissue were not significant (p>0.05) in the fish fed with 0 (D 1) and 0.1 (D 2) g kg-1 CuSO4.5H2O diets. The accumulation of Cu in the digestive system increased with increasing dietary Cu concentration and at periyot were significant (p<0.05) in group fed with the highest Cu concentration die