Poređenje gustine nasda nereis diversicolor u prirodnim i uzgojnim (anzali lagona) uslovima

Nereis diversicolor is regarded as a live food and is significantly effective in increasing stocks, enhancing tolerance in sturgeons and also increasing survival of sturgeon fry. Research conducted indicates that N. diversicolor is more abundant in May as compared to other months of the year. In February, only breeders of this species are found in the environment. N. diversicolor was found in four different weight classes from March 2009 to February 2010. They showed decrease in density with increase in temperature and reached the lowest numbers in February. In years 2009 and 2010, 200 sampling conducted monthly at the point where Caspian Sea mixes with the Anzali lagoon. Sampling was performed by Van Veen sampler with 400 cm2 cross section. Sediments were washed through a sieve with 0.5 mm mesh size. The residue along with Nereis was transferred to a dish, worms separated and transferred to lab. The density of worms per m2 was calculated according to the density formula. Two experiments were conducted to determine the best stocking density for the culture of N. diversicolor. Stocking density of 381-6350 worms m-2 were used in 6 trials initially and best growth was recorded in trial with density of 381 worms m-2. In the second experiment using 381-3175 worms m-2 in 7 trials, trial with 381 worms m-2 again showed better growth as compared to other trials. These results obtained were almost similar to those obtained for N. diversicolor is in its natural environment (447 worms m-2)

Feeding habits of sturgeon fishes in shallow coastal waters of Guilan Province, southern Caspian Sea

We collected sturgeon specimens from seven fishing stations operating 30 to 35 Km away from each other in Guilan province over the years 1999 MD 2000. Trawl nets six meters long were drawn using motorboats at each station, repeated three times for each season. Among the studied premature sturgeons, 121 Acipenser persicus specimens with an average age of less than two years and a length of 10 to 49.9 ± 0.77 cm showed full stomachs (57.17 % fullness). Among the mature specimens with an average age of 11 years and a length range of 90 to 194 cm, only three showed full stomachs (11.54 % fullness). The highest gut index in this study belonged to premature A. persicus. A one-way analysis of variance showed no significant difference in condition factor and gastro-somatic index among the different length groups (P<0.05). We found that the food consumed by premature A. persicus was comprised of eight genera of benthic invertebrates Hypania sp., Hypaniola sp., Pterocuma sp., Stenocuma sp., Abra ovata, Paramysis sp., Gammarus sp. and Nereis sp. Adult sturgeons were found feeding mainly on fish species belonging to Gobidae, Atherinidae and Clupeidae families. The main preys of premature A. persicus were polychaet worms Hypania sp. and Hypaniola sp. belonging to the class Sedantaria. Crustaceans Stenocuma sp. and Pterocuma sp. of the class Cumacea were also seen in the diet of the premature sturgeons. The main preys of adult A. persicus were fishes belonging to the family Gobiidae and secondary prey were fishes of the family Atherinidae

Efekat tri različite hrane na rast i preživljavanje larvi persijske jesetre (acipenser persicus)

A feeding experiment was conducted to evaluate growth and survival of Persian sturgeon larvae fed with live food (Nereis diversicolor and Daphnia spp.) and artificial diet. Diets were included: Diet 1: Dafnia (Dafnia magna), Diet 2: Nereis diversicolor worm; Diet 3: Mix of Daphnia (Daphnia spp.) (50%) and Nereis diversicolor (50%), Diet 4: Mix of Nereis diversicolor (50%) and concentrate food (50%) and Nereis diversicolor (50%); Diet 5: Mix of Daphnia spp. (33.33%) and Nereis diversicolor (33.33%) and concentrate food (33.33%). Persian sturgeon larvae were distinctly transferred to 15 tanks and fed for 15 days. For each treatment, 60 larvae were stocked into tanks. The total length and body weight of the fish were determined once before initiation of the experiment and at the end of the experimental period to assess their growth performance. Water quality parameters were recorded two times a day. There was significant difference (P0.05) were not found between diets 2 and 3 and also between diets 4 and 5. The value for BWI, PBWI, GR, DGI, SGR was higher in larvae fed mix of Nereis diversicolor and Daphnia spp. (diet 3) (p<0.05) and there was significant difference between all of groups. Except diet 3 there was no significant difference in the CF of fish fed the survey diets

The effects of temperature, salinity and photoperiod on sexual maturity and concomitant reproduction behavior in Nereis diversicolor

Nereis diversicolor worms were collected from the Anzali lagoon during the years 2004-2006 using Van Veen grab sampler with a surface area of 400cm ^(2). Water salinity, temperature and total organic matter (TOM) of sediments in the sampling region was determined. The worms were maintained in 0.5 tons (1x1m ^(2)) tanks until they reached a weight of 200-300mg. Sexual maturity in the samples was attained at 4-6C and spawning occurred at approximately 16°C. The first gametes were observed after the temperature increased from 6 to 16C. Sexual maturity was studied at various salinities (0.5, 5, 12, and 15 ppt). Results indicated that the worm attains sexual maturity at salinity 15ppt in a shorter period as compared to other salinities. No significant differences were observed between sexual maturity attained at salinities 12 and 15ppt (P>0.05). The effect of light and photoperiod in synchronizing reproduction in male and female N. diversicolor was also studied. We observed that reproduction behavior in adult worms increased for a period of one week at the end of each month after they were exposed to a prolonged photoperiod (L:D 16:8) followed by a period of dim light. Mature males crawled around outside the tubes in search of a female. In the presence of a mature female, the males released sperm directly in front of the female tube. Soon after, there was an increase in the activity of the females which showed intense ventilation movements. The female worms with their eggs already released began to carry the sperm into their tube. The ripe females nearby which had not yet laid eggs in their tubes released their gametes a few minutes after the male and began to carry sperm into their tubes. The fertilized eggs remained inside the tube protected by the female. The benthic larvae developed fast, feeding on the mucus and microbial film on the tube wall. After 10 to 14 days, larvae began to leave the tube. A few days later the females died

Prirodna hrana acipenser persicus gajenog u ribnjačkim jezerima

A study on live food in Acipenser persicus rearing ponds was carried out In four rearing ponds; two in the Shahid Beheshti hatchery and two ponds in the Yousefpour hatchery. Samples were collected from three points in each pond on a weekly basis. Samples were collected using plankton nets (mesh size 50 µm), Ruthner sampler and Ekman grab. Zooplankton and benthic samples were fixed in 4 % formalin solution for later analysis. Zooplankton species identified in water samples collected at all four ponds belonged mainly to two phyla; Arthropoda and Rotifera. Total abundance of zooplankton species was estimated 87576 individuals L-1 in the Yousefpour hatchery and 136626 individuals L-1 in the Shahid Beheshti hatchery. Insect larvae, oligochaeta worms and mollusks were found in the sediment samples collected from the Yousefpour hatchery while sediment samples collected from the Shahid Beheshti hatchery contained only insect larvae and oligochaeta worms. The total abundance of benthic organisms was 0.343 g m-2 in the Yousefpour hatchery and 1.28 g m-2 in the Shahid Beheshti hatchery. Condition factor in fishes ranged from 0.29-0.54 in the Yousefpour hatchery and from 0.30-0.47 in the Shahid Beheshti hatchery

In vitro activities of tetracyclines against different clones of multidrug-resistant Acinetobacter baumannii isolates from two Iranian hospitals.

Acinetobacter baumannii has emerged as one of the most challenging healthcare-related pathogens and its occurrence has increased worldwide, especially in patients admitted to intensive care units. A. baumannii isolates are frequently resistant to multiple antimicrobial agents and there are recent reports of isolates resistant to virtually all clinically relevant drugs. In the present study, the in vitro activities of tigecycline, minocycline and doxycycline against 67 MDR-AB isolates recovered from 29 burn and 38 non-burn Iranian patients hospitalised in Tehran and Tabriz, respectively, were studied. Tigecycline and minocycline may be still considered effective therapeutic options for MDR-AB infections. However, ongoing monitoring of A. baumannii susceptibility to these antibiotics is required

Summer and winter feeding behavior in Acipenser persicus and Acipenser stellatus in the south Caspian Sea

Feeding behavior in Acipenser persicus and Acipenser stellatus in summer and winter was studied from 2004 to 2006 simultaneously with the marine survey for sturgeon stock assessment. Bottom trawls (9m) on board the research vessel Sisara 2 (50 hsp) were used to collect specimens at depth below 10m, while specimens at depths more than 10m were collected using bottom trawls (24.7m) on board the Guilan Research Vessel (1000 hsp). Examination of stomach contents of 135 A. persicus and 80 A. stellatus specimens revealed that the food spectrum was composed of bony fishes (Neogobius sp., Atherina sp., Clupeonella cultriventris), invertebrates belonging to the family Ampharitidae (polychaeta worms including Hypanai sp. and Nereis diversicolor), various crustaceans (Gammarus sp. and Paramysis sp.) and the bivalved mollusc, (Abra ovate). Significant differences were detected in the frequency of prey items in the different seasons studied. Also significant differences (P<0.05)

Comparison of plankton and benthic organisms diversity and density in sturgeon hatcheries and assessing their effects on condition factor in sturgeon fingerlings

Phytoplankton and benthic organisms diversity and density were studied in six sturgeon rearing ponds in the Yousefpour and Shahid Beheshti hatcheries from 22 April to 1 July 2001. We used Ruttner sampler, plankton net with a mesh size of 50 microns and Ekman grab to sample the organisms on a weekly basis and fixed the samples in formalin solution 4% and then identified 22 genera of phytoplanktons for the three ponds in the Yousefpour hatchery and another 21 genera for the three ponds in the Shahid Beheshti hatchery. Planktons from the phyra Chlorophyta, Cyanophyta, Chrysophyta, Cryptophyta and Euglenophyta were present in the ponds. Schroederia sp. of the phyla Chlorophyta was the dominant species identified. We observed 2 x 106 and 1 x 106 cells of phytoplanktons per milliliter of pond water in the Yousefpour and Shahid Beheshti hatcheries respectively. The zooplankton phyla Arthropoda and Rotifera were represented with 9 genera in the two hatcheries showing a density of 36937 and 46603 zooplanktons per liter of water in the Yousefpour and Shahid Beheshti hatcheries respectively. Insect larvae and oligochaeta worms were the benthic organisms common to both hatcheries and mollusks were present only in the Yousefpour hatchery. The average benthic biomass was 1.58±0.19 and 2.16±0.75 g/m2 in the Yousefpour and Shahid Beheshti hatcheries respectively. The condition factor in sturgeon fingerlings of the Yousefpour hatchery varied from 0.294 to 0.554 while that of sturgeon fingerlings of the Shahid Beheshti hatchery were 0.297 to 0.6

Possibility of using fresh water rotifer Brachionus calyciflorus for feeding Persian sturgeon Acipenser persicus

Acipenser persicus, one of the native Species living in the southern part of the Caspian Sea, has high Percentage of larval mortality. Therefor to decrease the rate of mortality of larvae survival and to increase to regenerate properly during the active feeding process of fish larvae, while under artificial reproduction they were fed withe fresh water rotifer. Four types of feeding treatments were applied as follow: Treatment 1: Similar to normal process, first withe Artemia cyst then withe Daphnia Treatment 2: Mixture of Artemia, Rotifer and Daphnia; Treatment 3 freshwater Rotifera ;Treatment 4: fresh water Rotifer enriched with Vitamin C (Ascorbic acid- 6- Palmytat).Three replicates were used for each treatment. In the process of each observation 45 larvae in containers withe 100 liter capacity filled with 30 liters of water, after 8 days of external feeding process, were inspected closely, during which , they were under biometric measurement once every two days. Larvae were fed Four times a day at a rate of 25% of their body weight. The average temperature estimation was 22.5±0.5 centigrade, pH .of water being 85±0.1 while Oxygen proved to be 9.58±0.2 mg/l. At the end of the observation, the profile fatty acids of the remains were studied. The growth factors, the mouth size of the larvae and the expansion of the mouth size compared to the total length of the larvae during the whole observation were inspected. Credibility of data designated was examined by Shapiro Wilks test. Specific growth rate (SGR), weight growth (WG) and feed conversion ratio (FCR) were contemplated by one-way analysis test, and significant difference Tukey's test. The most notable diversity was evident between treatment 2, whose indicative factors were in the following order: 4.65± 0.06, 45.18±0.66, 4/48 ± 0/07 and treatment 4 whose indicative factors showed the following results: 10.47±0.04, 124.42±0.62, 1.51±0/008.For the determination of fatness rate and weight gains, Kruskal Valis and Man vit ni test were used .In this part of study , the highest diversity fatness appeared to be between treatment 4 ,reflecting 0.79±0.07 and treatment 2 showing the result 0.62±0.05.The highest gain was related to treatment 4, whit the rate of 99.33±0/68 mgr and the lowest gain occurred in treatment 2 white the rate 62.36 ± 0.65 mgr. This study also revealed that, the survival ratio connected with treatments 3 and 4, compared treatments 1 and 2, were significantly different. The profile of fatty acids also showed much higher percentage of PUFA and HUFA in treatments 3 and 4, than those in other treatments. Furthermore Brachionus calyciflorus proved to be a proper food supply for larvae. Therefore by building suitable pools next to the work side, other kinds of species fresh water rotifer could also be used as food improvements for feeding larvae

Study on the effects of applying garlic (Allium sativum) and Zataria multiflora extracts on Aeromonas hydrophila in Persian sturgeon (Acipenser persicus) fingerling

In order to investigate the effect of ethanol extracts of garlic (Allium sativum) and Zataria multiflora on Aeromonas hydrophila bacteria Persian sturgeon (Acipenser persicus)took the kids to the isolation and identification of bacteria, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of bacteria Aeromonas hydrophila by garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts to determine the lethal concentrations of hydroalchoholic extracts of garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts on Persian sturgeon (Acipenser persicus)children , and also to evaluate the efficacy and determine the effective doses of the bacterium Aeromonas hydrophila extracts of in vitro and in vivo were measured. Due to the absence of the Aeromonas hydrophila identification by molecular country in the study of bacteria isolated from sturgeon disease is suspected after detection by screening DNA extraction and molecular By toward action and results by NSBI Aeromonas hydrophila bacteria and Authentication Code NSBI was recorded in Gen Bank JX987090. Based on studies done in vitro (in vitro) in this study, the minimum inhibitory concentrations (MIC) Aeromonas hydrophila bacteria by extracts of garlic and thyme and arrange 1 mg/ml, 0.25mg/ml and the minimum bactericidal concentration (MBC) of bacteria Aeromonas hydrophila by the extracts, respectively, and 2mg/ml, 0.5mg/ml. Study on lethal concentration (LC50) of Zataria multiflora hydroalchoholic extract on fingerlings of Persian sturgeon showed that during 96h and 1h, the LC50 was 766.65 and 9933.44 mg/L, respectively. Also, LC50 of garlic extract during 96h and 1h was 1279.97 and 12624.08 mg/L, respectively. Investigation on white blood cells (WBC) showed significant difference in lymphocyte and neutrophil numbers in different treatments (P0.05). In this study, concentrations ranging from 400 to 1,000 mg/ml of hydroalchoholic extracts of Zataria multfor treating Persian sturgeon (Acipenser persicus) infected with the Aeromonas hydrophila by intraperitoneal injection were determined. Based on the results of the concentration of the extract to 800 mg/ml during shower hour was determined. Assay to determine the concentration of garlic extract on the bacteria in the Persian sturgeon (Acipenser persicus)concentration range of 600 to 1200 mg/ml determine the effective concentration of extract equivalent to 1,000 mg/ml during shower hour was calculated. Study on the pictures taken out from sections of gill, liver and kidny of Persian sturgeon fingerlings (Acipenser persicus) showed that in different doses of garlic (Allium sativum) and Zataria multiflora hydroalchoholic extracts the teretment grups were examined and some microscopic damages observed. They are hyperemia, adhesion in the gill filaments, cell necrosis, melanin pigments in gill primary filaments, cloudy swelling of hepatocytes, liver necrosis, hyperemia and increase in melanin pigments and melano macrophage centers in liver, glomerular changes such as congestion and blocked the dilation of Bowman's space, bleeding, cell necrosis, cloudy swelling of the in kidny