mohammad pourdehghani

The current study carried out to investigate the effects of adding salt (NaCl) in the diet of beluga, Huso huso and its impacts both on the function of intestinal enzymes and growth indices and food efficiency. In this regard, 480 species of Huso huso with a mean weight of 173.8 ± 0.49 g stocked in 12 fiberglasses 2000-liter tanks for 12 weeks. They fed a diet containing different levels of NaCl including 0, 3, 6 and 9 percent. Growth indices including final weight, SGR and daily growth showed significant differences in fishes of all treatments, except the fishes fed the diet containing comparing control group (p < 0.05) Weight gain percentage of fed fish at 6% sodium chloride level was significantly higher than fish fed control but no statistically significant difference was observed between other treatments. The mean FCR in fishes of control group was significantly higher than other treatments (p < 0.05). The mean rates ofrate of intestinal enzymes including Alkaline phosphatase, protease, lipase and amylase in the fishes fed by different levels of NaCl were significantly more than control group (p < 0.05). It is suggested to achieve a higher growth rate, improve food efficiency, reduction of production costs and enhancement of intestinal enzymes function. appropriate percentage of added NaCl is to be 3-6% per kilogram of diet for farmed beluga of at 150 to 700 g.

This study was carried out with the aim of measuring steroid hormones levels residue including 17β- estradiol (E2), 17α- hydroxy progesterone (17α - OHP), testosterone (T) and gonadotropine hormones (GTH I and GTH II) in farmed Persian (Acipenser persicus) and Siberian (Acipenser baerii) sturgeon in International Sturgeon Research Institute (Areo). 10 gram of eggs weighed and centrifuged at 3000 rpm per 10 minutes after homogenizing for extract. Results showed that maximum level of testosterone was 13.2 ± 0.97 ng/ml in Acipenser persicus and showed significant difference compared to Acipenser baerii. Maximum level of progesterone and E2 were 2.9 ± 0.1 and 1.4 ± 0.6 ng/ml in Acipenser persicus and showed significant difference compared to Acipenser baerii (P

Sturgeons are of commercially important fish species in the Caspian Sea, but there are few reports about their oxygen requirements. In the present study, the effect of different oxygen levels on hematological parameters were examined in two weight classes of great sturgeon Huso huso including small size (average initial weight 280.9 ± 49.2 g) and large size (average initial weight 1217.9 ± 138.1 g). Oxygen treatments including Hypoxia (2-3 mg/l), Normoxia (5-6 mg/l) and Hyperoxia (9-10 mg/l) were set up with managing inflowing water and using system equipped with oxygen enriching for Hyperoxygenation (pure oxygen injected). Fish were acclimated to experimental tanks for one week and then randomly were transferred to 9 tanks for each class (3 fish per tank in higher weight class and 6 fish per tank for lower one) and were kept for 8 weeks. HCT and MCHC at lower weight class and RBC, MCV and Neutrophil at higher weight class were significantly different between treatments.

This study was carried out on 24 farmed Huso huso (8 males and 16 females) in the international Sturgeon Research Institute during 3 years. Samples were collected based on different sexual maturation stages. Results showed that hematocrit (PVC)، hemoglobin (Hb) and red blood cells (RBC) was more in males than females and increased in both them related to sexual development especially at stage IV. Mean corpuscular volume (MCV) and Mean corpuscular hemoglobin (MCH) showed no significant difference between males and females، but Mean corpuscular hemoglobin concentration (MCH) showed significant increase in males and females related to sex development. White blood cells (WBC) were lower significantly in males than females and showed no significant difference at different sexual stages. The most percentage of leucocytes belongs to lymphocyte، neutrophile، eozynophile and monocytes and increase with sexual development without significant difference. There was no basophile. Results of this study showed that blood indices profile in Huso huso was similar to others sturgeon species and some parameters were dependent on sex and sexual maturation stages.

Blood indexes are very important in fish physiology, the more knowledge of blood indexes of fishes, the more ability of breeding and culturing of them. In the present study, The correlation between biochemical factors of blood (calcium, magnesium, total protein, cholesterol and glucose) with weight of female fishes and some biological characteristics of gonad (e.g. fertilization rate, fluid egg rate, gonadosomatic index, polarization index and oocyte diameter) in 9 female of the migratory population of Sterlet (Acipenser ruthenus) and 3 female of the migratory population of Siberian sturgeon (Acipenser baeri) in Spring of the 2012 were determined. In Sterlet, significant negative correlations were observed between blood Ca+2 with oocye diameter and fertilization rate (P<0.05). Also there was significant negative correlations between blood Ca+2 with fluid egg rate and gonadosomatic index (P<0.01). There was an invert correlation between total protein with oocyte diameter and fluid egg rate (P<0.05). Relationship between blood cholesterol with oocyte diameter, fluid egg rate, and fertilization rate and gonadosomatic index was direct, but this correlation was not significant. In Siberian sturgeon, there was an invert correlation between blood glucose and body weight (P<0.05). Also there was significant positive correlation between total protein and gonadosomatic index (P<0.05). Blood calcium was positively correlated with body weight, polarization index, fluid egg rate and fertilization rate but these correlations were not significant. Relationship between total protein and blood cholesterol with body weight, fluid egg rate, fertilization rate was negative that was not significant.

This study examined the effect of different starvation periods on hematological parameters including hemoglobin(MCV), hematocrit (MCH), red and white blood cells count and corpuscle indices (MCHC), of cultured juvenile Beluga (Huso huso), with an initial body weight of 45±0.91g. After adaptation to a dry diet for 10 days group s, with 15 fish in each group, were used for this experiment. Each group was randomly distributed to twelve 500L fiberglass tanks. Each tank had a flow-through system. The fish were exposed to 4 different feeding regimes; Control Group (fed four times daily); Group 1 (given 2 days of starvation); Group 2 (given 4 days of starvation); and, Group 3 (given 8 days of starvation). Analysis was done at the end of each starvation period by collecting blood from the caudal vein and immediately transporting the samples to the laboratory. The results of the analysis indicated that the different starvation periods did not affect the red blood cell count. The hematocrit value in the Control Group was significantly lower (p<0.05) than the fish group starved for 8 days. MCHC value in the control group was significantly lower (p<0.05) than the fish group starved for 2 days. The hemoglobin concentration, MCV and MCH, did not show any significant difference between the treated groups and the Control Group. Those groups with longer starvation periods showed that the white blood cell count decreased significantly (p<0.05). It could be concluded that short-term starvation periods weaken the immunological system of cultured juvenile Beluga.

Sexual cells in male fishes are microscopic and smaller than eggs in females. Due to the late maturation age in sturgeons, the biopsy of gonads and histological studies are one of the most important and reliable ways to detect and separate males and females from each other at early ages. The aim of the present study was to determine and divide the sexes in farmed Acipenser persicus reared under artificial conditions. In order to detect and determine sexual maturation stages, gonads of 81 farmed A. persicus were sampled by biopsy. Samples were fixed and studied by light microscope. Results showed that males and females were 30 (37%) and 51 (63%) individuals, respectively. The determination of sexual maturation stages in A. persicus showed that 16% were at stage I, 23.5% at stage I - II, 59.3% at stage II and 1.2% at stage III. The number of females was higher than that of males, but sexually mature females were at lower maturation stages than males in the same age and rearing conditions