Reproductive effects of dietary soy phytoestrogens, genistein and equol on farmed female beluga, Huso huso

In this study, 54 five-year-old farmed female beluga at stage II of sexual maturation were treated with 0 [control], 0.2, 0.4, 0.8 and 1.6 g of dietary soy equol [EQ] and genistein [GE] per each kilogram [kg] of diet during a year. Blood samples were collected and ovarian biopsy was performed quarterly. Results showed that 64.4% of the Huso huso sexually matured at EQ 0.4 g/kg and reached stage IV of sexual maturation. Oocytes diameters increased significantly at all concentrations of EQ and 0.2, 0.4 and 0.8 concentrations of GE and reached a maximum [3 +/- 0.2 mm] at 0.4 g/kg EQ concentration at the end of experiment [P<0.05]. Blood plasma testosterone [T] level was 0.3 +/- 0.06 ng/ml at the beginning and reached a maximum [21.04 +/- 1.91 ng/ml] at EQ 0.4 g/kg at the end of the experiment [P<0.05]. 17a-estradiol [E2] levels increased significantly at some concentrations of GE and EQ at the end as compared to the beginning, reaching a maximum [12.6 +/- 1.04 ng/ml] at EQ 0.4 g/kg at the end of the experiment [P<0.05]. 17- hydroxy progesterone [17á-OHP] levels showed no significant difference [P>0.05]. In conclusion, EQ at a 0.4 g/kg concentration showed more powerful positive reproductive effects than other concentrations of EQ and GE in farmed female H. huso. Comparatively, EQ showed more estrogenic effects on ovary development in comparison to GE concentrations. Its use is therefore suggested as an additive to diets to induce ovary development in Huso huso

[Effects of short-term starvation on hematological parameters in cultured juvenile beluga]

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

[Biopsy and histological study of gonads from farmed acipenser persicus]

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