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Falahatkar B.,Guilan University | Akhavan S.R.,Guilan University | Akhavan S.R.,Khorramshahr Marine Science and Technology University | Poursaeid S.,Islamic Azad University at Rasht | Hasirbaf E.,Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex
Journal of Applied Ichthyology | Year: 2014

This study describes the sex steroid profiles and hematological indices of 5-year-old reared female Siberian sturgeon, Acipenser baerii, at perinucleolus and migratory stages to ascertain whether they are influenced by the maturity stage. Fish of 2923 g mean weight and 89 cm mean length were reared in rectangular concrete tanks (25 × 3 × 0.6 m, mean water temperature 16.2 ± 2.2°C, fed a diet with 38.2% crude protein and 7% crude fat in 10 kg m-2). Blood samples were taken for serum steroid levels, including 17-β estradiol (E2), testosterone (T), 17α-hydroxy progesterone (P) and hematological indices (packed cell volume, hemoglobin, red blood cells, white blood cells, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration as well as leukocyte differential counts). Hematological indices and the leukocyte differential count showed no significant differences among fish at the perinucleolus and migratory stages. The results indicated significant differences in E2 levels among fish at the perinucleolus and migratory stage, but the T and P levels showed no significant differences between stages. This study indicates that serum sex steroid measurements and histological observations can segregate females effectively at the perinucleolus and migratory stages; however, the hematological parameters did not discriminate females at these stages. Such observations provide basic information to achieve a method to determine with high accuracy the stage of sexual maturity, for better sturgeon aquaculture management. © 2014 Blackwell Verlag GmbH. Source

Falahatkar B.,Guilan University | Akhavan S.R.,Guilan University | Akhavan S.R.,Khorramshahr Marine Science and Technology University | Tolouei Gilani M.H.,Fisheries General Directory of Guilan | Abbasalizadeh A.,Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex
Iranian Journal of Veterinary Research | Year: 2013

Since sturgeons have no external sexual dimorphism and there are no external markers to determine sex, internal examination of the gonads should be used to sex identification. The present study describes the biopsy method and histological observations of the gonads of great sturgeon (Huso huso) in both sexes at different age classes. Sex and maturity stages of 226 great sturgeons were identified through gonadal biopsy and histological observations. A 20-25 mm incision was made with a sharp scalpel through the ventral midline between pectoral and pelvic fins, that allowed gonads to be viewed. Determination of sex and maturity stage was successfully performed in all fish. The sex ratio under culture conditions was 1:0.84 (female: male). Most males and females were at mid-spermatogenesis and pre-vitellogenesis stages, respectively. No apparent mortality and infection was observed after surgery and gonad biopsy in fish. Results of this study showed that sex could be identified by this method when fish are 3-year-old or more. Therefore, biopsy technique is a simple and cost-effective tool in sturgeons and has an important role in aquaculture management and conservation benefits. Source

Falahatkar B.,Guilan University | Tolouei Gilani M.H.,Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex | Falahatkar S.,Guilan University | Abbasalizadeh A.,Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex
Aquaculture | Year: 2011

Laparoscopy is a fast, effective, and minimally invasive method for determining the sex and reproductive stage of great sturgeon (Huso huso) via a small (1. cm) incision in the abdominal wall. The system consists of a 7.5. mm, 22. cm long cystoscope sheath, fiber-optic light, halogen cold light source, video camera with a control unit, and a color monitor, and allows direct viewing of the abdominal organs of a fish. In this study, it was used on 120 farm raised great sturgeon ranging in age from 3 to 16. years. Sex identification was successfully performed in all fish which 95.8% sexed with laparoscopy alone. Five of 120 sturgeon required gonadal biopsy and microscopic examination to confirm sex. The unidentified fish were smaller and thinner than others. Results showed that both sexes could be identified with this system as early as 3. years of age and the sex ratio under culture conditions of females, males and unidentified sex were 56.6, 39.2 and 4.2%, respectively. While most reproductive applications of laparoscopy in great sturgeon related to the visual identification of gender and reproductive stage, the ability to biopsy the gonad enabled these identifications to be objectively assessed using histology. Our results suggest that laparoscopy is an efficient technique for sex identification at different ages and determination of gonadal development stages in great sturgeon. The ability to safely perform minimally invasive reproductive surgery in this species may have important management and conservation benefits during the culture period or wild population assays. © 2011 Elsevier B.V. Source

Ghiasi S.,Guilan University | Falahatkar B.,Guilan University | Dabrowski K.,Ohio State University | Abasalizadeh A.,Shahid Dr. Beheshti Sturgeon Fish Propagation and Rearing Complex | Arslan M.,Ataturk University
Aquaculture International | Year: 2014

The present study aimed to investigate the effect of thiamine on growth, hematological, egg thiamine content and oocyte nucleus migration indices in sterlet sturgeon (Acipenser ruthenus). A total of 45 female fish (698.6 ± 8.9 g) were distributed in nine fiberglass tanks with three treatments (each in three replicates). Experimental fish were fed once a day with practical diet supplemented with 1 g kg−1 amprolium hydrochloride (as the antithiamine) for 5 months before spawning. Thiamine hydrochloride was injected to fish with one of three doses at 0, 5 and 50 mg kg−1 body weight (BW) at three different stages. At the end of each month, fish were weighed and growth parameters such as weight gain, specific growth rate, feed efficiency and final weight were determined. At the end of the 5-month period, hematological parameters and egg thiamine content were measured. The results showed no significant differences in terms of growth performance. Hemoglobin, number of red blood cells and white blood cells were not significantly different among the treatments, but hematocrit was significantly higher in fish injected with 5 mg kg−1 BW thiamine. The mean corpuscular volume and mean corpuscular hemoglobin were not significantly different, but lower value of mean corpuscular hemoglobin concentration was observed in fish injected with 5 mg thiamine. Percentage of lymphocytes, neutrophils, eosinophils and monocytes were not significantly different among treatments. The results of the germinal vesicle migration index at different stages showed no significant differences in different groups. Results showed that free thiamine, thiamine pyrophosphate and total thiamine in eggs significantly increased at 50 mg kg−1 injection dose compared with the control, but no significant different was found in thiamine monophosphate. The results revealed that thiamine injection to sterlet broodstocks has positive accumulation in egg thiamine content and some hematological parameters but have no effect on growth and ovarian maturation. We conclude that thiamine can affect some physiological features of broodstock, which needs to be specified in further studies. © 2014, Springer International Publishing Switzerland. Source

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