جستجوی مقالات مرتبط با کلیدواژه « Sturgeon » در نشریات گروه « دامپزشکی »

Serum complement is valuable tool in determining the health status of fish. This study was conducted to examine in vitro activity of serum complement as an indicator of innate immunity in four sturgeon species, Acipenser stellatus, A. baeri, A. nudiventris and Huso huso (Chondrostei: Acipenseridae). The Effects of different temperatures, concentrations and volumes of serum on alternative complement pathway activity were evaluated using standard haemolytic assays in four sturgeon species (A. stellatus, A baeri, A. nudiventris and Huso huso). Results indicated significant relation between measured hemolysis and concentration, volume and temperature (p

The Endothelial PAS domain-containing protein 1 (EPSA1) is the key transcriptional regulator of hypoxic response and Vascular Permeability Factor (VPF) is an important growth factor for vascular development and angiogenesis.
In the present study, the levels of the EPSA1 coding gene and VPF transcripts were evaluated during Larval development of Beluga, Huso huso.
Samples at 12 developmental time-points including 1, 2, 4 days before hatch (eyed eggs), fresh hatched larvae (0), and larvae 1, 3, 6, 10, 15, 20, 25 and 50 days post-hatching were collected and stored in a −80 °C freezer until RNA extraction. Changes in EPSA1 and VPF mRNA expression were studied and differences in normalized mRNA expression levels among the different developmental stages of H. huso were analyzed by one-way analysis of variance (ANOVA).
The transcripts of EPSA1 and VPF were detected in all developmental time-points of H. huso from embryos to fingerling fish. Our results revealed that the mRNA expression of EPSA1 and VPF was low during embryonic development and then upregulated significantly at the time of hatch and early larval time-points, whereas in the late larval development stages they started to decline.
This study showed that there is an association between the EPSA1 and VPF mRNA expression during larval development of H. huso. The up regulation of EPSA1 and VPF transcripts at the time of hatch and during yolk sac fry development of H. huso is likely tied to the role of them in vasculogenesis and angiogenesis.

Growth behavior of five lactic acid bacteria previously isolated from Persian sturgeon (Acipenser persicus), were evaluated at different pH, temperature and salt concentrations. Also, antibacterial activity of extracellular products (ECPs) of this LAB were assessed to Aeromonas hydrophila . Further, their antibiotic susceptibility was determined with some commonly used antibiotics in aquaculture. In an in vivo work the effect of Lactococcus lactis as the supplementary diet was evaluated on growth performance of Persian sturgeon for a period of 56 days. Strong growth of all LAB were seen at 20 and 300 C, as well as 40 and 80 g L-1 NaCl. The LAB ECPs exhibited varied results of antagonism to the A. hydrophila with maximum activity observed at temperature between 25 and 300 C Also, the higher antagonistic activity was observed for ECPs of W. cibaria , P. pentosaceus, and L. lactis at pH 9. Both W. cibaria and E. faecalis were resistance to oxytetracycline, erythromycin, trimethoprim sulfamethoxazol, enrofloxacin, florfenicol, and flumequine, while L. lactis was sensitive to oxytetracycline, erythromycin, enrofloxacin, florfenicol. These results showed that use of L. lactis can act as a positive probiotic in Persian sturgeon feed via improvement of fish growth performance, feed efficiency and fish health.

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.

Brain development of the Acipenser gueldenstaedtii (A. gueldenstaedtii) was described from days 1 to 36، post-hatch (dph) in this study. Larvae were euthanized، and serial sections of specimens were examined. Our ontogenical study was determined to concentrate on important parts of the brain containing forebrain، midbrain and hindbrain. The primary observation of the telencephalon was in 1-week-old specimens. The size of the forebrain remained relatively steady and did not demonstrate considerable changes، as compared to the other parts of brain. The diencephalon changes were noticeable in 3-week-old A. gueldenstaedtii. 2 major parts of mesencephalon، (tegmental portion and optic tectum) were detected during 4 weeks of development. As in other chondrosteans، the cerebellum appeared highly developed. Medulla oblongata appeared larger in 1-week-old specimens than in 4-week-old specimens.