نشریه علوم و فنون شیلات
سال سوم شماره 3 (پیاپی 8، پاییز 1393)

The effect of a probiotic containing five species of bacilli at four levels of 0 (control), 1×106CFU/ml (T1), 1×107 CFU/ml (T 2) and 1×108CFU/ml (T 3) per 100g of feed on the growth performances, resistance and survival of rainbow trout fry, Oncorhynchus mykiss (463±32 mg) were compared in a 60-days feeding trial. Growth parameters, such as ADG, SGR, RGR and TGC, were significantly enhanced (p

Morphological changes of the chloride cells and the α1b subunit gene expression of Na+K+ATPase in triploid rainbow trout (70.6 g average weight) were studied upon direct transferring to 6, 12 and 18 ppt salinities. Changes in abundance, distribution pattern, and the sectioned area of the chloride cells was studied through classic histology and Na K+ATPase localization was performed through immunofluorescence light microscopy using a mouse monoclonal antibody IgGα5. Gene expression of Na+K+ATPase α1b subunit was studied by semi-quantitative gene expression methods.No mortality occurred among the fish in all salinities during the 10-days experimental period and treated fish kept their plasma osmolality at standard physiologic levels. All the fish also showed similar distribution pattern in their chloride cells that were distributed on filaments, between and over lamella. Histological studies confirmed some abnormal morphological changes such as lamella interruption. Immunohistochemical studies showed the highest number of the chloride cells on lamella and between lamella in 18 ppt and the maximum sectional area of the chloride cells in freshwater. Gene expression of Na+K+ATPase α1b subunit had direct correlation with increasing trend of salinity. In conclusions, triploid rainbow trout was found to be adaptable to the various experimented salinities and could be recommended for rearing in brackish water.

In a completely randomized design, the effects of two probiotic bacteria, Bifidobacterium animalis and B. lactis at four concentrations of 0 (control), 1×109 (T1), 2×109 (T2) and 3×109 (T3) CFU 100g-1 on nutritional parameters of rainbow trout fry (0.538 ± 0.197 g body weight) were compared for 60 days, with each treatment carried in three replications. A significant difference was observed between treatments and the control in protein and lipid gain and also body composition (p

The effects of pyrene on gill, liver and kidney of common carp (Cyprinus carpio) were examined by exposing 30 fish (140 ±10 g to pyrene at sublethal concentrations of 10, 50 and 100 µg/l for 35 days. Samples were taken from the organs and fixed in bouin fixative; then, dehydrated, cleared, parafinated and cut by microtome according to the standard method. Afterwards, all sections were studied by light microscope. In gill tissue, lamella hyperemia, hyperplasia, S shaped, and clubbing were observed, while lamella fusion and necrosis were observed in higher concentration of pyrene. Hepatocytes vacculation, congestion of sinusoids, macrophages loaded with hemosiderin were seen in the liver, while in higher concentrations of pyrene, picnotic and kariolized nuclei, and tissue necrosis were seen. Tubule casts, hyperemia, degenerating tubules were seen in kidney exposed to lower concentrations of pyrene, while hemosiderin-laden macrophages, degenerating tubules with greater intensity as well as necrosis was observed in higher concentrations. The results indicated that pyrene may have negative effects on homeostasis, fish health and vital organs in short time exposure due to histological changes, while it could have greater impacts in long term exposure and higher concentrations.

The effect of thiamine injection at doses of 0 (T0), 5 (T5) and 50 (T50) mgkg-1 body weight on reproductive performanceof 45 females (698.7 ± 8.9 g) sterlet sturgeon (Acipenser ruthenus) was investigated in fiberglass tanks. Fish were fed practical diets supplemented with 1 g/kg amprolium hydrochloride (as the anti-thiamine) once a day for 5-month before spawning. At the end of 5 months trial, no significant difference was observed in germinal vesicle migration among treatments (p>0.05). Estradiol level was not significantly different (p>0.05), but testosterone was affected by injection of thiamine (p0.05) among the treatments, but number of eggs per gram and hatching rate were significantly different (p

In a completely randomized design, the effects of heavy metals of Cd, Cu, Pb and Ni at concentrations of 0, 5, 50 and 100 mg/l on chlorophyll a and biomass in green algae Scenedesmus quadricauda were investigated for 14 days under laboratory conditions of 23 °C, 12 h light: 12 hours light and light intensity of 60 mol photons/m2/s. The lowest density, chlorophyll a and dry biomass obtained at 100 mg/l in all of the heavy metals. The mean (±SE) highest increasing rates of chlorophyll a were 24.2±1.1, 23.1±0.8, 36.7±1.4 and 35.5±1.2% for Cd, Cu, Pb and Ni, respectively. Correspondingly, the reduction rates based on dry biomass were 51.5±3.1, 35.2±1.1, 47.9±1.6 and 56.6±2.8% for Cd, Cu, Ni and Pb, respectively. The results showed that heavy metals made significant reduction on chlorophyll a and dry biomass in S. quadricauda.

The effects of fennel essential oil (Foeniculum vulgare) at 5 levels of 0 (control), 100, 200, 400 and 600 mg per kg. of diet on growth performance, survival, body composition and hematological parameters of the Caspian kutum fry, Rutilus frisii kutum, were investigated in a 60-days feeding trial. No significant differences in the growth related parameters and survival were observed among treatments (p>0.05). The highest level of fat was observed in 100 mg fennel essential oil (p

The geometric morphometrics method was applied to study the morphological differences in 95 specimens of Kura barbel (Barbus lacerta, Heckel 1834) collected from three riverine ecosystems of the Sefidrud basin, viz. Taleghan, Totkabon and Kloraz Rivers. For this purpose, the left sides of the specimens were photographed. Then, 14 Landmark-points were defined and digitized on 2D pictures using Tpsdig2 software. The landmark data, after generalized Procrustes analyzing, were analyzed by PCA, CVA with p-value obtained from permutation test and cluster analysis. The results showed a significant differences between the populations in terms of body shape (P