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The growth hormone (GH) gene has important regulatory roles in postnatal somatic growth, metabolism and development of vertebrates and fish. The aim of this study was to identify the genetic variations in a partial region of the GH gene and its associations of these variants with growth traits using DNA sequencing in 200 European sea bass (Dicentrarchus labrax) individuals. Five haplotypes (HAP1-5) and ten novel SNPs were identified as g.1557 A>T, g.1611 T>C, g.1663 C>G, g.1799 T>C, g.1824 T>C, g.1912 T>A, g.2052 G>C in the 1st partial intron, 2nd exon, 2nd intron and 3rd partial exon of GH gene in European sea bass. The genotypes of GH g.1611 T>C locus were found associated with total weight, fillet weight and head length (p < 0.05). Association between the genotypes of GH g.1557A>T and pre-anal length, abdominal length were found statistically significant (p < 0.05). Similarly, the genotypes of g.1857 C>T loci which caused the synonymous mutation in phenylalanine amino acid were found associated with standard length (Pp < 0.05). Taken together, the HAP4 with positive effects on body weight and length traits should be used as a potential marker to improve the accuracy of selection in European sea bass in Mediterannean conditions.

The growth hormone (GH) gene has an important regulatory roles in postnatal somatic growth, metabolism and development of vertebrates and fish. The aim of this study was to identify the genetic variation of the GH gene and its associations with growth traits by DNA sequencing in 200 European sea bass (Dicentrarchus labrax) individuals. Ten novel SNPs were identified as g.1557 A > T, g.1611 T > C, g.1663 C > G, g.1799 T > C, g.1824 T > C, g.1912 T > A, g.2052 G > C in the 1st partial intron, 2nd exon, 2nd intron and 3rd partial exon of GH gene in European sea bass. The genotypes of GH g.1611 T > C locus were found associated with total weight, fillet weight and head length (p GH g.1557A > T and pre-anal length, abdominal length were found statistically significant (p GH g.1799 T > C locus which caused the amino acid change from Leucine to Serine (L8S) were found related to body length and abdominal length (p GH peptide. Thus, these SNPs have an effect on the growth traits of European sea bass and could be used for genomic selection in European sea bass breeding.

The growth of fish in intensive fish farming is carried out completely by the feeds supplied from externally. Different ingredients are used in feed production. The nutritional content of these ingredients is checked when purchased or brought to the factory. These ingredients are then stored until feed production. Storage duration and storage temperatures directly affect the freshness criteria of feed ingredient materials. Especially when high-energy ingredients with high levels of fat are stored in poor storage conditions, the fats in the ingredients are oxidized, therefore the peroxide number increases and the ingredient becomes bitter. Oxidation not only destroys the lipids in fish feeds but also vitamins. Slow growth, poor feed evaluation, color darkening, lethargy and deaths have been reported in fish fed with diets that are oxidized and inadequate in vitamin E. In this study, oxidation levels of fish feed ingredients were determined due to different storage conditions. Generally, the number of peroxides increased due to the increase in storage time and temperature, depending on the type of raw materials and oil content.

Insulin-like growth factor II (IGF-II) is a peptide hormone which plays a crucial role in the growth and metabolic regulations of vertebrates. in this study, we identified single nucleotide polymorphisms on IGF-II gene in the European sea bass (Dicentrarchus labrax) and revealed the potential association between the genotypes of IGF-II gene and growth traits in 150 European sea bass. the polymorphisms were determined using DNA sequencing and PCR-RFLP methods in two different regions of IGF-II gene. An AT indel and two SNPs as g.5127711C>G and g.5127731G>T in the intron 2 region, and one SNP as g.5129188C>T in the intron 3 region of IGF-II gene in the European sea bass were reported for the first time with this study. Two different genotypes (GG, TG) were observed and the G allele was predominant (65%) in the IGF-II-Ndel locus. Associations between the genotypes of IGF-11-Ndel locus and body weight and total length were statistically significant (P, Scientific Research Projects Coordination Unit of Ege University [16-SUF-025], The funding of the current research was supported by Scientific Research Projects Coordination Unit of Ege University (Project No: 16-SUF-025). We thank Evren Koban Bastanlar for her scientific contributions during writing stage of this article.

Fats have a function in transmitting the necessary fatty acids to fish as well as being an energy source in fish nutrition. in particular, high-chain unsaturated fatty acids are needed for feeding saltwater fish. in this study, the fatty acid composition of fish oils obtained from some whole-body fish and fish by-products used in the fish-feed industry in Turkey was determined and compared with each other. Accordingly, SFA (Saturated fatty acids) ratios were in the range of 15.57-33.38% in the oils obtained from the whole-body fish and in the range of 16.3-31.89% in the oils from fish by-products; MUFA (Monounsaturated fatty acids) ratios were in the range of 24-38.69% in the oils obtained from the whole-body fish and in the range of 25.81-47.57% in the oils from fish by-products; PUFA (Polyunsaturated fatty acids) ratios were in the range of 31-36.73% in the oils obtained from the whole-body fish and in the range of 33.54-36.78% in the oils from fish by-products. Given DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) ratios which are among the most important PUFAs for nutrition, it was determined that DHA ratios were in the range of 14.08-19.10% in the oils obtained from the whole-body fish and in the range of 3.55-15.28% in the oils from fish byproducts, whereas EPA ratios were in the range of 8-9.89% in the oils obtained from the whole-body fish and in the range of 2.63-15.28% in the oils from fish by-products., Balık beslemede yağlar enerji kaynağı olmasının yanı sıra gerekli olan yağ asitlerinin balıklara iletilmesinde de görev alırlar. Özellikle, deniz balıklarının beslenmesinde yüksek zincirli doymamış yağ asitlerine ihtiyaç vardır. Bu çalışmamızda Türkiye balık yemi sektöründe kullanılan bazı tüm vücutlu balıklardan ve balık yan ürünlerinden elde edilen balık yağlarının yağ asidi kompozisyonları tespit edilmiş ve birbiri ile karşılaştırılmaları yapılmıştır. Elde edilen sonuçlara göre tüm vücutlu balıklardan elde edilen yağlarda SFA (Doymuş yağ asitleri) oranlarının %15,57-33,38 arasında olduğu, balık yan ürünlerinden elde edilen yağlarda ise %16,3-31,89 arasında değiştiği saptanmıştır. Ayrıca tüm vücutlu balıklardan elde edilen yağlarda MUFA (Tekli doymamış yağ asitleri) oranlarının %24-38,69 arasında, balık yan ürünleri yağlarında ise %25,81-47,57 arasında değiştiği, tüm balıklardan elde edilen yağlarda PUFA (Çoklu doymamış yağ asitleri) oranlarının %31-36,73 arasında, balık yan ürünleri yağlarında ise %33,54-36,78 arasında değiştiği tespit edilmiştir. Besleme açısından en önemli PUFA’lar dan olan DHA (docosahexaenoic asit) ve EPA (eicosapentaenoic asit) oranlarına baktığımızda, DHA oranlarının tüm balıklardan elde edilen yağlarda %14,08-19,10 arasında, balık yan ürünleri yağlarında ise %3,55-15,28 arasında değiştiği, EPA oranlarının ise tüm balıklardan elde edilen yağlarda %8-9,89 arasında, balık yan ürünleri yağlarında ise %2,63-15,28 arasında değiştiği tespit edilmiştir.

Bu çalışmada, Umbrina cirrosa (Linnaeus, 1758) ve Argyrosomus regius (Asso, 1801)'un akuakültür şartlarında suni döllenme yoluyla çaprazlanmasıyla elde edilen hibrit bireylerinin bazı morfometrik özellikleri ve boy-ağırlık ilişkileri incelenmiştir. 39 bireyde boy, ağırlık ve kondisyon faktörü değerleri sırasıyla 26,12 - 48,67 mm, 0, 7 - 0, 99 g, 0,81- 1,09 arasındadır. Boy-ağırlık ilişkisi, 0, 000009 * TL 3.006 r = 0, 99 olarak hesaplanmıştır. Regresyon analizi sonuçlarına göre bireyler b değerine göre izometrik büyüme (b=3) göstermiştir. Biyotrik analizler sonunda örnekler arasında 10 morfometrik ölçüm içinde en önemli farklılık üst çene-pektoral yüzgeç (MPL) arasında (P, In this study, length-weight relations and some morphometric characteristics of hybrid juveniles obtained by crossing of Umbrina cirrosa (Linnaeus, 1758) and Argyrosomus regius (Asso, 1801) via artificial fertilization under aquaculture conditions were investigated. Lengths, weights and condition factors of 39 hybrid juvenile specimen varied between 26.12 and 48.67 mm, 0.7 and 0.99 g, 0.81 and 1.09 respectively. Length-weight relationship (W) was calculated (0.000009 * TL3.006 r= 0.99). Individuals have shown isometric growth (b=3) according to the results of regression analyze by b value. All 10 morphometric measurements presented significant differences between the examined species in this study at the end of biometrical analyses except distance of maxilla and pectoral fin (MPL) (P

Bu çalışmada, 6.73 gram ortalama canlı ağırlığa sahip sivriburun karagöz (Diplodus puntazzo) yavrularının yemlerinde farklı oranlarda soya küspesi ununun balık unu yerine kullanımı araştırılmıştır. 12 haftalık besleme denemesinin sonunda, %0, 25, 50 ve 75 oranlarında azaltılan balık unu yerine, aynı oranlarda attırılarak kullanılan soya küspesi içeren yemlerle beslenen balıkların ortalama canlı ağırlıkları sırası ile 35.57, 33.81, 29.87, 24.62 g. olarak belirlenmiştir. Sonuçta, balık ununun sivriburun balıklarının beslenmesinde yine birinci derece ham protein kaynağı olduğu; bununla birlikte balık unu yerine %25 oranında soya küspesi kullanımının balıkların canlı ağırlık gelişiminde belirgin bir farklılığa neden olmadığı tespit edilmiştir

Tilapia were acclimated to the water source which had 8 precipitation (ppt) of salinity in the experimental unit before the experiment started and then, they were transfered to five different saltwater (SW) treatments: SW (8 ppt), 50% SW (12 ppt), 100% SW (16 ppt), 150% SW (20 ppt), and 200% SW (24 ppt). The objectives of this study were; to investigate the effects of five different salinities on specific growth rate (SGR), weight gain (WG), food intake (FI) and survival of tilapia in the long term trial (30 days) and find out how salinity affects muscle water content, hematosomatic index (HSI), and blood chemistry (sodium, chloride, potassium, glucose, total protein and triglycerides) in the short term trial (6 to 12 h). In the long-term trial, six fish were stocked in each aquarium. They were fed with commercial feed (Bagci trout) to satiation twice a day and individually weighed at ten-days interval. Growth rate was highest in the 50% SW (SGR 0.95 ± 0.18% per day); there was no significant difference among the first three treatments. Growth rate was lowest in 200% SW (SGR 0.23 ± 0.08% per day). Weight gain and food intake showed identical results as SGR. Survival was high in the first three groups (72.2 ±1 9.2 to 100.0 ± 0.0) but it was lowest in the 200% SW treatment (22.2±19.2%). In the short-term trial, six tilapia were placed per aquarium. They were exposed to SW, 50, 100, 150 and 200% SW treatments and the fish were gradually acclimated to salt water. Blood samples were taken to analyse plasma sodium, chloride, potassium, total protein and triglycerides. Liver and muscle samples were collected for HSI and moisture values. Plasma sodium chloride increased in parallel with salinity rise. Total protein and triglycerides significantly reduced as salinity increased. Glucose and potassium were not altered significantly. HSI and muscle water content decreased when salinity concentration was elevated. Blood chemistry demonstrated that isosmotic water concentration was between 8 and 12 ppt. Salinity did not affect HSI and moisture until it reached as much as 16 ppt (100% SW). The results show that the optimum condition for farming blue tilapia, Oreochromis aureus, both with respect to growth rate and metabolic parameters is at salinities lower than 12 ppt. This is an important finding for the tilapia industry. Keywords : Tilapia, salinity, growth, survival, metabolism African Journal of Biotechnology Vol. 12(19), pp. 2715-2721

The aim of the study was to investigate the effects of dietary lipid on the growth and feed utilization of Meagre (Argyrosomus regius Asso, 1801), taking into account their feeding behavior of collecting food from the bottom of the cages. The fish (141.07 +/- 0.5g, average weight +/- SD; 22.18 +/- 0.53 cm, average total length +/- SD) were fed three isonitrogenous experimental diets (45% crude protein, dry matter) containing 16% (group A), 18% (group B), and 20% (group C) crude lipids for 570 days. The fish were stocked into 9 net cages (16 m diameter; 7 m deep) at a density of 16000 fish per cage with 2 replications. At the end of the experiment fish in the A, B, and C groups reached 1054.59 +/- 5.9, 1026.32 +/- 4.3, 955.31 +/- 2.3 mean live weight (g) and 45.78 +/- 1.6, 44.43 +/- 1.4, 43.88 +/- 1.4 mean total length (cm) respectively. FCR and CF values were 1.99, 2.07, 2.14 and 1.999, 1.131, 1.170 respectively for each group, at the end of the study. VSI, HIS, and GSI values were also calculated. Growth rate in fish from group A (fed the lowest lipid diet) was superior to the other dietary groups. Cross sections of their liver were checked and were found to have less lipidosis.

Chantier qualité GA; International audience; The meagre Argyrosomus regius is a large Sciaenid fish known to reproduce in the eastern Atlantic and Mediterranean Sea in just five distinct and restricted geographic areas: along the Mauritanian coast and at estuary openings (Gironde, Tagus, Guadalquivir and Nile). The biological traits of A. regius (high dispersal capabilities, high fecundity, long larval phase, overlapping generations, reproduction until 40 years of age) are, in principle, favourable to high gene flow, which should lead to genetic homogeneity over large geographic scales. Nevertheless, the high geographic distances between the few reproductive areas leads one ask whether there is genetic differentiation in this species. In the present study, the genetic differentiation of the wild A. regius was investigated across most of its natural range from the Atlantic Ocean (France, Portugal, Spain, Mauritania) to the Mediterranean Sea (Egypt, Turkey), using 11 microsatellite markers previously identified in another Sciaenid, the red drum Sciaenops ocellatus. At least two very distinct groups could be identified, separated by the Gibraltar Strait. Genetic divergences (FST values) were intermediate between the Atlantic samples (0.012–0.041), high between Egypt and the Atlantic (0.06–0.107) or Aegean Sea (0.081) and extremely high between the Aegean Sea and the Atlantic (0.098–0.168). A. regius exhibited a very high level of genetic differentiation rarely reported in marine fishes. These results also demonstrate the existence of a sixth independent spawning area in the Menderes delta (Turkey). Factors potentially involved in this very high genetic fragmentation are discussed, including physical barriers, glaciation pulses and biological traits.

Özet: Bu çalışmada, bir Nil tilapyası (Oreochromis niloticus) populasyonunda yaş, cinsiyet ve ağırlık ölçümleri kullanılarak; hasat ağırlığı için, damızlık değerleri, En İyi Doğrusal Sapmasız Tahminleme (BLUP) yöntemi kullanılarak tahmin edilmiştir. Herhangi bir seleksiyon uygulanmamış bu tilapya populasyonunda hasat ağırlığı için tahmin edilen ortalama damızlık değer tahmini, 0,03 bulunmuştur. Erkek tilapya balıklarının hasat ağırlığı için ortalama damızlık değer tahminleri (2,908), dişilerin ortalama damızlık değer tahminlerinden (-2,740) daha yüksek bulunmuş olup, cinsiyet ile hasat ağırlığına ait damızlık değer tahminleri arasındaki ilişki önemli bulunmuştur. Damızlık seçiminde, bir bireyin tüm özellikleri için, en güvenilir tahmin imkanını veren BLUP yöntemi kullanılmıştır., In this study, breeding values in a Nile Tilapia (Oreochromis niloticus) population for harvest weight was estimated according to weight, age and sex data using Best Linear Unbiased Prediction (BLUP) method. Mean estimated breeding value (EBV) for harvest weight in this unselected tilapia population was found 0.03. Mean EBV of male fish (2.908) for harvest weight was found higher than the mean EBV of females (-2.740) and relation between sex and estimated breeding values of harvest weight was found significant according to a t test. The BLUP method which gives opportunity of the most reliable estimations for all traits of an individual in selecting broodstock was used

800 adet (28±2.3 gr) sarıağız (Argyrosomus regius), içeriğinde baryum sülfat ilave edilen yemlerle beslenmiş ve yemlemeden 2 saat sonra başlayan toplam 30 saatlik incelemede, her iki saatte bir 10’ar örnek alındıktan sonra öldürülmüş ve röntgenleri çekilmiştir. Röntgen filmlerinin incelenmesiyle 28±2.3gr ağırlığındaki sarıağızların 20°C sıcaklıkta midesel boşaltım süresinin ortalama 9 saat, sindirim sisteminin tamamı ile boşalma süresinin ise ortalama 21 saat olduğu tespit edilmiştir

Bu çalışma, Ege Bölgesinde yetiştiricilik çalışmaları yapılan sarı ağız (Argyrosomus regius Asso, 1801) balıklarında görülen Benedenia sciaenae van Beneden, 1856 enfestasyonunun tedavisinde hidrojen peroksidin (H2O2) etkili olup olmadığını ortaya koymak amacıyla yapılmıştır. Deneme öncesinde 20 adet sarıağız balığı anestezi edilerek deri üzerinde 1544 adet parazit sayılmış, 3 grup oluşturularak hidrojen peroksit (300 ppm, 15 dk) ile tedavi denemeleri yapılmıştır. Deneme sonrasında bir tank içinde 1517 adet ölü B. sciaenae sayılmıştır. Denemenin yapıldığı balıklar tekrar anestezi edilerek, deri üzerinde parazit taraması yapılmış, hiçbir parazite rastlanmamıştır. 21 °C, 40 ppt tuzlulukta gerçekleştirilen deneme süresinde toksikasyon belirtileri gözlenmemiştir. Hidrojen peroksidin etkisi % 98,25 olarak tespit edilmiştir, This research was carried out to evaluate the efficacy of hydrogen peroxide (H2O2) as a treatment for Benedenia sciaenae van Beneden, 1856 infestation in cultured meagre (Argyrosomusregius Asso, 1801). Before the experiment, a total of 1544 parasites were counted on the skin of anesthezied 20 meagre Argyrosomus regius Asso, 1801. Treatment trials were performed by using hydrogen peroxide on three groups. At the end of the trials, a total of 1517 dead parasites were found at the bottom of the an experiment tank, however no parasite was found on the skin of the fish cured and anesthezied for the parasite investigation. Toxications symptoms were not observed in the trials where the temperature was 21 °C and salinity was 40 ppt. The effect of hydrogen peroxide was determined as 98,25%.

Age and growth of adult gilthead seabream, Sparus aurata were determined from 332 specimens (total N = 476), collected from purse-seiners, in the south-eastern Aegean Sea from November 2006 to January 2007. The fork length and body wet weight ranged from 26.5 to 51.5 cm (mean: 36.6 ± 0.18) and from 375 to 2600 g (mean: 1009.2 ± 14.16), respectively. Age groups were varied between 2 and 7. Growth parameters were estimated as L∞ = 64.97 ± 12.93 cm, K = 0.14 ± 0.07 year−1, t0 = −2.47 ± 1.09 year−1, and index of phi-prime was Φ′ = 2.772 ± 0.51. The length–weight relationship equation of all fish was calculated as W = 0.0515 × L2.737 (r2 = 0.95). The mean condition factor was estimated as 2.058. Mortalities (M, F and Z) and exploitation rate (E) of gilthead seabream from the Aegean Sea were 0.34 year−1, 0.77 year−1, 1.11 year−1and 0.69 year−1, respectively. The result of E indicated that the population was overexploited.

Markalama ve etiketleme yöntemleri özellikle uzun süreli yetiştiricilik çalışmalarında oldukça öneme sahiptir. Kullanılacak yöntem, çalışmanın başarısını belirlediği gibi özellikle yaşama oranları üzerinde de etkilidir. PIT (Passive integrated transponder) ve VI-Alfa (visible implant alphanumeric) markalar kullanılarak yapılan çalışmada, marka etkinliği (marka geri dönüşüm oranı) PIT marka kullanılan gruplarda %95.31 ve %96.62 olarak tespit edilirken, VI-alfa grubunda ise net olarak okunan marka sayısı dikkate alındığında marka etkinliği %42.35 olarak tespit edilmiştir. Yaşama oranlarına bakıldığında ise, PIT marka gruplarında ilk 30 gün sonunda yaşama oranları %95,31 ve %96,62 olarak gerçekleşirken VI-alfa grubunda ise hiçbir kayba rastlanmadığı tespit edilmiştir. Bu sonuçlara göre PIT markaların özellikle uzun süreli su ürünleri yetiştiriciliği çalışmalarında kullanımının çalışma başarısı açısından daha verimli olduğu tespit edilmiştir

Bu çalışmada, çipura larvaları 21-35. günler arasında farklı oranda artemia ve mikrokapsül yemler kullanılarak beslenmiş, larvaların bu günler arasındaki gelişme ve yaşama oranları tespit edilerek, artemia kullanım oranlarının azaltılmasına çalışılmıştır. Çalışmada deneme grupları %100 artemia, %25 Mikrokapsül + %75 artemia, %50 mikrokapsül + %50 artemia, %100 mikrokapsül olacak şekilde beslenmişlerdir. Artemia kullanım oranlarının azaltılması üzerine yapılan çalışmada, %25 mikrokapsül + %75 artemia besleme rejimi uygulanan gruptaki yaşama ve gelişme oranlarının kontrol grubu olan artemia grubu ile istatistiki olarak farklılık göstermediği tespit edilmiştir. Bu sonuca göre 21-35. günler arasında mikrokapsül yem kullanılarak, çipura larvası yetiştiriciliğinde yem giderleri içinde büyük bir pay tutan artemia kullanım oranlarının %25 azaltılabileceği, bunun larvaların gelişme ve yaşama oranı üzerinde olumsuz bir etkisi olmadığı tespit edilmiştir

The performance of microdiets (MDs) for larvae of marine fish is frequently improved when they are co-fed with Artemia. This suggests that nutritional factors in the live food are positively influencing the ingestion, digestion and assimilation of the MD. This paper reviews recent advances in MD development on the gilthead seabream with special emphasis on studies that isolated, identified and tested these live food factors in MD with the aim of improving their performance. MD ingestion rates in gilthead seabream larvae increased up to 120% when the fish were exposed to the visual and chemical stimuli of various concentrations of Artemia nauplii. The free amino acids (FAA) alanine, glycine and arginine and the compound betaine were identified from the Artemia rearing medium as metabolites, which stimulated this larval response. Similarly, MD supplemented with phospholipids (PL), particularly phosphatidylcholine (PC), stimulated feeding activity and was consumed up to 45% better in young larval seabream. Moreover, dietary PC appears to have in parallel and/or in tandem a postprandial enhancing effect on lipoprotein synthesis, resulting in improved transport of dietary lipids from the mucosa of the digestive tract to the body tissues. Live food may also contribute exogenous enzymes to the digestion process or provide factors that stimulate larval pancreatic secretions or activate gut zymogens. Seabream larvae ingesting MD supplemented with porcine pancreatic extract (0.05% DW diet) showed a 30% increase in assimilation and demonstrated significantly (P

A 180-day feeding trial was carried out in net cages to examine replacement of fishmeal with soybean meal supported by meat/bone meal and blood meal in practical diets for sea bass (Dicentrarchus labrax L. 1758). Triplicate groups of fish (initial body weight 110 g) were fed one of four isonitrogeneus (crude protein 46%) and isolipidic (10%) diets. A commercial sea bass diet containing 64% fishmeal as the sole animal protein served as the control. The other three diets contained 0, 20%, or 35% fishmeal and the reduced fishmeal was replaced by different levels of soybean meal, meat/bone meal, and blood meal. The final body weight of fish fed the diet containing 20% fishmeal, 50% soybean meal, 10% meat/bone meal, and 4% blood meal was significantly higher than that of the other three treatments. Results indicate that fishmeal can be reduced to 20% when soybean meal, meat/bone meal, and blood meal are used together in the diet.

800 adet (28±2.3 gr) sarıağız (Argyrosomus regius), içeriğinde baryum sülfat ilave edilen yemlerle beslenmiş ve yemlemeden 2 saat sonra başlayan toplam 30 saatlik incelemede, her iki saatte bir 10’ar örnek alındıktan sonra öldürülmüş ve röntgenleri çekilmiştir. Röntgen filmlerinin incelenmesiyle 28±2.3gr ağırlığındaki sarıağızların 20°C sıcaklıkta midesel boşaltım süresinin ortalama 9 saat, sindirim sisteminin tamamı ile boşalma süresinin ise ortalama 21 saat olduğu tespit edilmiştir., X-Ray usability for determination of gastric and digestive track evacuation time in meagre Argyrosomus regius Asso, 1801. 800 meagre (Argyrosomus regius) were fed with formulated diets including barium sulphate and 10 fish were sampled, killed and x-rayed every 2 hours starting 2 hours after feeding for total 30 hours. Gastric evacuation time at 20°C for meagre at 28±2.3gr weight was determined average for 9 hours, complete average digestive track evacuation time was determined for 21 hours by investigating x-ray.

Bu çalışma, Ege Bölgesinde yetiştiricilik çalışmaları yapılan sarı ağız (Argyrosomus regius Asso, 1801) balıklarında görülen Benedenia sciaenae van Beneden, 1856 enfestasyonunun tedavisinde hidrojen peroksidin (H2O2) etkili olup olmadığını ortaya koymak amacıyla yapılmıştır. Deneme öncesinde 20 adet sarıağız balığı anestezi edilerek deri üzerinde 1544 adet parazit sayılmış, 3 grup oluşturularak hidrojen peroksit (300 ppm, 15 dk) ile tedavi denemeleri yapılmıştır. Deneme sonrasında bir tank içinde 1517 adet ölü B. sciaenae sayılmıştır. Denemenin yapıldığı balıklar tekrar anestezi edilerek, deri üzerinde parazit taraması yapılmış, hiçbir parazite rastlanmamıştır. 21 °C, 40 ppt tuzlulukta gerçekleştirilen deneme süresinde toksikasyon belirtileri gözlenmemiştir. Hidrojen peroksidin etkisi % 98,25 olarak tespit edilmiştir

Bu çalışma, Ege Bölgesinde yetiştiricilik çalışmaları yapılan sarı ağız (Argyrosomus regius Asso, 1801) balıklarında görülen Benedenia sciaenae van Beneden, 1856 enfestasyonunun tedavisinde hidrojen peroksidin (H2O2) etkili olup olmadığını ortaya koymak amacıyla yapılmıştır. Deneme öncesinde 20 adet sarıağız balığı anestezi edilerek deri üzerinde 1544 adet parazit sayılmış, 3 grup oluşturularak hidrojen peroksit (300 ppm, 15 dk) ile tedavi denemeleri yapılmıştır. Deneme sonrasında bir tank içinde 1517 adet ölü B. sciaenae sayılmıştır. Denemenin yapıldığı balıklar tekrar anestezi edilerek, deri üzerinde parazit taraması yapılmış, hiçbir parazite rastlanmamıştır. 21 °C, 40 ppt tuzlulukta gerçekleştirilen deneme süresinde toksikasyon belirtileri gözlenmemiştir. Hidrojen peroksidin etkisi % 98,25 olarak tespit edilmiştir., The effect of hydrogen peroxide (H2O2) for Benedenia sciaenae van Beneden, 1856 (Monogenea : Capsalidae) infestations in cultured meagre Argyrosomus regius Asso, 1801. This research was carried out to evaluate the efficacy of hydrogen peroxide (H2O2) as a treatment for Benedenia sciaenae van Beneden, 1856 infestation in cultured meagre (Argyrosomus regius Asso, 1801). Before the experiment, a total of 1544 parasites were counted on the skin of anesthezied 20 meagre Argyrosomus regius Asso, 1801. Treatment trials were performed by using hydrogen peroxide on three groups. At the end of the trials, a total of 1517 dead parasites were found at the bottom of the an experiment tank, however no parasite was found on the skin of the fish cured and anesthezied for the parasite investigation. Toxications symptoms were not observed in the trials where the temperature was 21 °C and salinity was 40 ppt. The effect of hydrogen peroxide was determined as 98,25%.

Bu çalışmada, çipura larvaları 21-35. günler arasında farklı oranda artemia ve mikrokapsül yemler kullanılarak beslenmiş, larvaların bu günler arasındaki gelişme ve yaşama oranları tespit edilerek, artemia kullanım oranlarının azaltılmasına çalışılmıştır. Çalışmada deneme grupları %100 artemia, %25 Mikrokapsül + %75 artemia, %50 mikrokapsül + %50 artemia, %100 mikrokapsül olacak şekilde beslenmişlerdir. Artemia kullanım oranlarının azaltılması üzerine yapılan çalışmada, %25 mikrokapsül + %75 artemia besleme rejimi uygulanan gruptaki yaşama ve gelişme oranlarının kontrol grubu olan artemia grubu ile istatistiki olarak farklılık göstermediği tespit edilmiştir. Bu sonuca göre 21-35. günler arasında mikrokapsül yem kullanılarak, çipura larvası yetiştiriciliğinde yem giderleri içinde büyük bir pay tutan artemia kullanım oranlarının %25 azaltılabileceği, bunun larvaların gelişme ve yaşama oranı üzerinde olumsuz bir etkisi olmadığı tespit edilmiştir., In this study, gilthead sea bream larvae were fed by using different concentrations of artemia and microcapsule feeds between the 21st and 35th days, artemia usage ratios were tried to be decreased determining the growth and survival ratios of the larvae between these days. During the study, the test groups were fed by using 100% Artemia, 25% Microcapsule + 75% Artemia, 50% Microcapsule + 50% Artemia and 100% Microcapsule ratios. At the end of the experiment on decreasing artemia usage ratios, it was determined that the growth and survival ratios of the group having 25% Microcapsule + 75% Artemia feeding regime were similar to those of the control artemia group. According to these results, it was concluded that between the 21st and 35th days, artemia usage ratios which is take very important part of the expenses of marine fish larval rearing, could be decreased by 25% using microcapsule feeds, and that it did not have any effect on larval growth and survival.

Bu çalışma, çipura (Sparus aurata L., 1758) larvalarının besin keselerini tüketmelerinin ardından ilk besin almaya başladıkları dönemdeki yem tüketimlerini tespit etmek amacı ile yapılmıştır. Çalışmada larvalar, $^{14}C$ izotopu ile markalanan rotifer (Brachionus plicatilis Müller, 1786) ve 50-65 $mu$ m büyüklüğündeki mikrokapsül yemler kullanılarak beslenmişlerdir. Çalışmada larvaların beslenmesinde 3 farklı yemleme uygulaması yapılmıştır. Birinci grup rotifer, ikinci grup mikrokapsül yem, üçüncü grup ise radyoaktif mikrokapsül+radyoaktif olmayan rotifer ile beslenmiştir. Çalışma sonucunda, 5 günlük larvaların rotifer tüketim miktarı 0,347 $mu gl^{-1}h^{-1}$, mikrokapsül yem tüketim miktarı 0,152 $mu gl^{-1}h^{-1}$, mikrokapsül yem+ rotiferin birlikte kullanıldığı gruptaki tüketim miktarı ise 0,088 ngrV'olarak saptanmıştır.Çahşma, çipura larvalarının ilk beslenmeye geçtikleri dönemde mikrokapsül yemleri, canlı yeme kıyasla daha düşük miktarlarda olmakla birlikte, tüketebildiğim, mikrokapsül yem+rotiferin birlikte kullanılması durumunda ise mikrokapsül yem tüketim oranının düştüğünü göstermiştir., This study was done to determine the feed consumptions of seabream (Sparus aurata L., 1758) larvae during their first feeding period just after they consumed their egg yolks. During the experiments, the larvae were fed by using rotifers (Brachionus plicatilis Müller, 1786) that were marked with $^{14}C$ isotope and by microcapsule feeds which were 50-65 $mu$ m in size. Three different feeding regimes were used to feed the larvae. First group were fed by rotifer, second group by microcapsule feeds, and third group by radioactive microcapsule + non-radioactive rotifer. At the end of the study, for 5-days old larvae, the rotifer consumption ratio was found to be 0.347 $mu gl^{-1}h^{-1}$, microcapsule feed consumption ratio to be 0.152$mu gl^{-1}h^{-1}$, and 0.088 $mu gl^{-1}h^{-1}$ for the group in which microcapsule feeds and rotifer were used together. This study showed that sea bream larvae could consume microcapsule feeds during first feeding period, although at lower ratios when compared to live feeds, and that using microcapsule feeds together with rotifer decreased the microcapsule feed consumption ratio.

Ozone (O3) dissolved in seawater (ODS) was evaluated, as an egg disinfectant, on the spawn of captive gilthead sea bream, Sparus aurata, brood stock. Four contact times (CT) were tested (0.6, 1.2, 2.4 and 4.8 mg min L−1) where CT was calculated by multiplying the dissolved O3 concentration (0.3 mg L−1) by different exposure periods (2, 4, 8, 16 min). There was also a disinfected seawater treatment that contained no O3 or derived compounds (CT 0) and an untreated seawater control. All ODS treatments reduced egg surface bacterial counts to zero, which was significantly (P 97%) compared with the control and CT 0 treatments (ca. 70%). The results suggest that a 2-min exposure of eggs to 0.3 mg O3 L−1 of ODS (CT 0.6) would improve current protocols in marine larviculture.