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The genetic differentiation among Turkish populations of the narrow-clawed crayfish was investigated using a partial sequence of cytochrome oxidase subunit I gene (585 bp) of 183 specimens from 17 different crayfish populations. Median joining network and all phylogenetic analyses disclosed a strong haplotype structure with three prominent clades diverged by a range between 20 and 50 mutations and substantial inter-group pairwise sequence divergence (5.19-6.95 %), suggesting the presence of three distinct clades within the Anatolian populations of Astacus leptodactylus. The divergence times among the three clades of Turkish A. leptodactylus are estimated to be 4.96-3.70 Mya using a molecular clock of 1.4 % sequence divergence per million years, pointing to a lower Pliocene separation. The high level of genetic variability (H d = 95.8 %, π = 4.17 %) and numerous private haplotypes suggest the presence of refugial populations in Anatolia unaffected by Pleistocene habitat restrictions. The pattern of genetic variation among Turkish A. leptodactylus populations, therefore, suggests that the unrevealed intraspecific genetic structure is independent of geographic tendency and congruent with the previously reported geographic distribution and number of subspecies (A. l. leptodactylus and A. l. salinus) of A. leptodactylus.

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Thermal shock-induced triploid and unshocked control hybrids between rainbow trout (Oncorhynchus mykiss) and Black Sea trout (Salmo labrax) and their parental species were produced under hatchery condition by using heat shocks. Triploidization reduced eyed egg rate and alevin yield in all groups. Low survival rate was observed in both shock-induced triploid hybrid and non-shock-induced control hybrids. Although hybrids demonstrated low body weight during the ¢rst feeding stage, they reached higher body weight by day 200 when compared with Black Sea trout and rainbow trout. A higher speci¢c growth rate was calculated as 3.60 in the triploid hybrid groups,1.41in the triploid Black Sea trout groups and 2.27 in the triploid rainbow trout groups between days 110 and 200. A lower condition factor was determined in the hybrid than in the diploid parental species. A negative value of mid-parent heterosis (MPH) performance was deected for condition factor, and a favourable MPH was detected for speci¢c growth rate and weight in hybrids.

This study aimed to determine the anesthetic efficacy of clove oil and 2-phenoxyethanol on doctor fish (Garra rufa) at two different water temperatures. Experimental fish (1.2 ± 0.2 g mean weight) were subjected to 25, 50, 75 and 100 μL L-1 clove oil and 100, 200, 300, 400 and 500 μL L-1 2-phenoxyethanol concentrations at water temperature of 15 and 25 °C, and the induction and recovery times were investigated. Results showed that induction and recovery times in doctor fish were significantly affected by clove oil and 2-phenoxyethanol concentrations as well as water temperature. The interaction of anesthetic concentration and water temperature on all induction stage time was significant in clove oil. Between the anesthetic concentration and temperature interaction was significant for recovery times in both anesthetic agents. The induction time decreased significantly with increasing concentration of both anesthetic agents at water temperature of 15 and 25 °C. The lowest effective concentrations that produced induction within 3 min and recovery within 5 min were 50-75 μL L-1 of clove oil and 300 μL L-1 of 2-phenoxyethanol in both 15 and 25 °C respectively. The results also indicated that clove oil was effective at 4-fold lower concentrations than 2-phenoxyethanol, but the recovery time was longer than 2-phenoxyethanol. These results suggest that clove oil and 2-phenoxyethanol were effective anesthetics and could be used as anesthetic agents in doctor fish.

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In this study, we aimed to investigate the acute stress responses of Black Sea trout to acute thermal fluctuations. Black Sea trout (184.22 g mean weight) were transferred from a private trout farm to a research center and restocked in a fiberglass square tank. After acclimation to culture conditions (at a water temperature of 15 °C) for 2 weeks, the fish in the experiment were exposed to 25 °C water temperature for 30 min, and the stress responses of the fish were examined at 1, 3, 6, 12, 24, 36, 48, and 72 h. After acute thermal shock, cortisol and glucose levels increased during the first hour in the experimental group. However, cortisol and glucose levels returned to their normal values after 6 and 36 h, respectively. Lysozyme activity decreased at 3 h and rose to its normal level at 12 h after the experiment. Total protein and serum ion concentrations were also affected and fluctuated due to acute thermal stress. Short-term acute thermal exposure also caused a serum ionic imbalance in the trout, but homeostasis was restored at 72 h.

SummaryThis study was conducted to examine the effects of feeding diets, different dose of vitamin E contains, on female and male Black Sea trout's (Salmo labrax) reproductive performance. Broodfish were fed with dry feed contained 100 (control), 250, 500, 1000 mg kg -1 vitamin E. Milt volume, spermatozoid number, fecundity and egg size were determined. Milt volume and sperm number were positively affected at a dose of 250 and 500 mg kg -1 vitamin E in the diet. A similar positive trend was also observed at the dose of 1000 mg kg -1 . Egg size is not affected by dietary vitamin E dose, but there are positive relationship between total fecundity and dietary vitamin E dose especially at the first stripping (P<0.05).Keywords: Milt, α-tocopherol, Broodstock, Fecundity, Vitamin E Vitamininin Karadeniz Alabalığı (Salmo labrax) Damızlık Stoklarında Üreme Performansına Etkisi ÖzetBu çalışma Karadeniz Alabalığı'nda (Salmo labrax) 6 hafta süreyle, yemlerine farklı dozlarda ilave edilen E vitamini ile beslemenin üremeye etkisini ortaya koymak amacıyla yapılmıştır. Anaç stoktaki balıklar 1 kg yemde 100 mg (kontrol grubu), 250 mg, 500 mg ve 1000 mg olacak şekilde E vitamini ilave edilen yemle beslenmişlerdir. Sperm hacmi, spermatazoa sayısı, fekondite ve yumurta çapı verileri incelenmiştir. Sperm hacmi ve spermatozoa sayısı 250 ve 500 mg E vitamin içeren yemlerle beslenen balıklarda pozitif yönde etkilenmiştir. Benzer ilişki 1000 mg kg -1 dozda da görülmüştür. Yumurta büyüklüğü yemdeki E vitamininden etkilenmezken, özellikle ilk sağımda total fekondite ve vitamin E miktarı arasında pozitif ilişki vardır (P<0.05).