Turbot, Scophthalmus maximus, is a commercially important demersal flatfish species distributed throughout the Black Sea. Several studies performed locally with a limited number of specimens using both mitochondrial DNA (mtDNA) and microsatellite markers evidenced notable genetic variation among populations. However, comprehensive population genetic studies are required to help management of the species in the Black Sea. In the present study eight microsatellite loci were used to resolve the population structure of 414 turbot samples collected from 12 sites across the Black Sea. Moreover, two mtDNA genes, COI and Cyt-b, were used for taxonomic identification. Microsatellite markers of Smax-04 and B12-I GT14 were excluded from analysis due to scoring issues. Data analysis was performed with the remaining six loci. Loci were highly polymorphic (average of 17.8 alleles per locus), indicating high genetic variability. Locus 3/20CA17, with high null allele frequency (>30%), significantly deviated from HW equilibrium. Pairwise comparison of the F ST index showed significant differences between most of the surveyed sampling sites (P < 0.01). Cluster analysis evidenced the presence of three genetic groups among sampling sites. Significant genetic differentiation between Northern (Sea of Azov and Crimea) and Southern (Turkish Black Sea Coast) Black Sea sampling sites were detected. The Mantel test supported an isolation by distance model of population structure. These findings are vital for long-term sustainable management of the species and development of conservation programs. Moreover, generated mtDNA sequences would be useful for the establishment of a database for S. maximus.

The efficacy of clove oil as an anaesthetic was evaluated in larvae of Russian sturgeon (Acipenser gueldenstaedtii) using four anaesthetic concentrations varying from 0.20 to 0.75 g L )1 Mean length, 13.7 ± 0.70 mm, 44 larvae placed individually to the anaesthetic bath, and induction (I-1 and I-2) and recovery times (R-1 and R-2) recorded at 18.0 ± 0.01°C. Larvae failed to respond to external stimuli ‡3 min (3.19 min) and recovered in ‡5 min (5.10 min) at 0.20 g L )1 and at the other three doses larvae reached to syncopal stage in <3 min and recovered from anaesthesia <10 min. As expected, the higher dose of clove oil resulted in significantly shorter anaesthesia induction and longer recovery times. While correlation coefficients between induction time and dose determined as negative; r = 0.87 and a positive correlation r = 0.86 has been found between doses and recovery times (P < 0.01). The study demonstrated that clove oil can be used as an effective anaesthetic in larvae of Russian sturgeon and higher dose of clove oil prolonged the recovery time.

This study was conducted to determine the effect of age, sex and weight on the middle intestine villi morphology of fifth-generation Black Sea trout (Salmo labrax Pallas, 1814). The fish were kept in the freshwater ponds (June-October) and marine cages (November-May) to provide the life cycle of species. Intestine tissue samples were taken during period when fish were kept in marine cages. Our results showed that, middle intestine villi morphology changed depending on fish age (I, II, III, IV and V years old) and different live weight (low weighted and high weighted) of similar ages (16 months old). The lowest intestine villi development was obtained in I years old fish. This was followed by II years old fish. The highest intestine villi development was obtained in III years old fish. Besides, intestine villi development of high weighted fish was higher than those of low weighted fish. However, it was found that middle intestine villi morphology did not changed depending on sex. Karadeniz Alabalığı (Salmo labrax Pallas, 1814)'nın Bağırsak Villi MorfolojisiÖz: Bu çalışma, 5. (F5) nesil Karadeniz alabalığı (Salmo labrax Pallas, 1814)'nın bağırsak villi morfolojisi üzerine yaş, cinsiyet ve ağırlığın etkisini belirlemek için yapılmıştır. Türün doğal yaşam döngüsünü sağlamak için, balıklar tatlısu havuzlarında (Haziran-Ekim) ve deniz kafeslerinde (Kasım-Mayıs) tutulmuştur. Bağırsak doku örnekleri, balıkların deniz kafeslerinde tutulduğu dönemde alınmıştır. Çalışmada elde edilen sonuçlara göre, orta bağırsak villi morfolojisi balığın yaşına (I, II, III, IV ve V yaş) ve aynı yaştaki balığın (16 aylık yaş) farklı canlı ağırlığına (düşük ve yüksek ağırlıklı) bağlı olarak değişmiştir. En düşük bağırsak villi gelişimi I yaşlı balıklarda görülmüş, bunu II yaşlı balıklar takip etmiştir. En yüksek bağırsak villi gelişimi ise III yaşlı balıklarda görülmüştür. Ayrıca yüksek ağırlığa sahip balıkların bağırsak villi gelişimi düşük ağırlıklaki balıklardan daha yüksek bulunmuştur. Ancak orta bağırsak villi morfolojisi üzerine cinsiyetin etkisinin olmadığı tespit edilmiştir.

Summary The aim of this report is to provide an overview of the current status of efforts on the potential rehabilitation of sturgeon populations in Turkish waters, describing the structure and the outcome of projects carried out since 2006 and identifying the strategic needs for sturgeon conservation measures at a national level. It is well known that there were six sturgeon species occurring around Turkish Black Sea coasts while entering the rivers, mainly Kızılırmak, Yeşilırmak, Sakarya and Çoruh Rivers for spawning. Anadromous sturgeon species have been strictly protected throughout Turkey since 1997. Conservation and management measurements have been implemented since 1970s. However, this was apparently with little success as stocks continued to decline and habitats deteriorated further, threatening the stocks with extinction. At the same time the needs for survival are not well documented. A project was initiated on 30 January 2006, consisting of seven‐work packages including studies on population structure, reproduction, habitat assessment, genetic variability between and within stocks and the development of protective management strategies and plans. The work covered the Turkish Black Sea coastline and the rovers Yeşilırmak, Kızılırmak, Çoruh and Sakarya. Actively sampled and/or accidentally caught specimens have been tagged by T‐bars and released after measurements and tissue sampling for genetic analyses. In addition, broodstocks of Russian sturgeon (Acipenser gueldenstaedtii), Beluga (Huso huso), and stellate (A. stellatus) are being built by rearing fish at the Central Fisheries Research (Yomra, Trabzon, Turkey) Institute. Reproduction studies have mainly focused on sperm collection, cryopreservation and induced spawning as well as on larval rearing.

The efficacy of clove oil as an anaesthetic was evaluated in Juvenile of Russian sturgeon (Acipenser gueldenstaedtii) under two experiments. Dose response examined using four anaesthetic concentrations varying from 0.22 to 0.90 g/L of clove oil and effect of exposure duration on the recovery time analysed for 5 and 10 min. Mean body length (cm), 24.9±1.37 and weight (g) 63.2±10.89, n=120, juvenile Russian sturgeon placed individually to the anaesthetic bath prepared with clove oil, and induction (I1: Sedation and I2: Loss of equilibrium) and recovery times (R1: Regain of equilibrium and R2: Sedation) recorded in seconds. Allowing fish remain in the anaesthesia after fish reaching anaesthesia stage, time to recovery from anaesthesia recorded. Fish exposed to clove oil failured to respond to external stimuli and reached to anaesthesia, sympocal stage in <3 min and recovered in <5 min at all doses except 0.22 g/L dose of clove oil. Exposure five and ten minute to anaesthesia at the 0.22, 0.45 and 0.90 g/L concentrations, fish recovered from anaesthesia in <10 min, except 0.90 g/L. The higher dose of clove oil resulted in significantly shorter induction time and prolonged recovery time. While correlation between induction time and dose determined as negative, r= -0.594 and a positive correlation has been found between dose and recovery time, r=0.422 (P<0.05). The study demonstrated that clove oil can be used as an effective anaesthetic measuring length and weight of juvenile Russian sturgeon and dose and exposure duration effect on time to recovery from anaesthesia of clove oil.Keywords: Anaesthesia, clove oil, dose response, exposure duration, recovery time. Karaca Mersinlerinin Karanfil Yağı ile Bayıltılmasında Anesteziye Maruz Kalma Süresinin Ayılmaya Etkisi ÖzetKaraca mersinlerinde (Acipenser gueldenstaedtii) karanfil yağının anestetik etkisi iki çalışma ile ölçülmüştür. Doz tepkisi 0,22'den 0,90 g/L'ye kadar değişen dört farklı konsantrasyonda ölçülmüş ve anesteziye 5 ve 10 dakika maruz kalmanın anesteziden kurtulmaya etkisi incelenmiştir. Ortalama boyları 24,9±1,37 cm ve ağırlıkları 63,2±10,89 g olan karaca mersinleri karanfil yağı ile hazırlanan bayıltıcı solüsyona tek tek yerleştirilmiştir. Her balığın bayılma ( I1: hafif bayılma ve I2: tam bayılma) ve ayılma (R1: hafif ayılma ve R2: tam ayılma) süreleri saniye düzeyinde kayıt edilmiştir. Balıklar tam bayıldıktan sonra anestetik solüsyon içinde bekletilmiş ve ayılma süreleri kayıt edilmiştir. Karanfil yağına maruz kalan balıklar, 0,22 g/L hariç diğer dozlarda 3 dakikadan az sürede bayılarak dış uyarıya tepki vermemiş ve beş dakikadan az sürede ayılmışlardır. Anesteziye 5 ve 10 dakika maruz kalan balıklar 0,22, 0,45 ve 0,90 g/L dozlarda, 0,90 g/L doz hariç, 10 dakika içinde ayılmışlardır. Karanfil yağı dozu arttıkça bayılma süresi kısalmış ve ayılma süresi uzamıştır. Bayılma süresi ile doz arasında negatif r= -0,594 ve doz ile ayılma süresi arasında pozitif r=0,422 (P<0,05) ilişki bulunmuştur. Bu çalışma karanfil yağının karaca mersinlerinin boylarını...