توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Organozeolite, A new absorbent for removing harmful anions from recirculating aquaculture effluent
اطلاعات انتشار: سومین همایش ملی آب و فاضلاب با رویکرد بهره برداری، سال
تعداد صفحات: ۵
Waste water treatment is important for an economical and environmentally friend aquaculture enterprise. In last 30 years, synthetic and natural zeolites have been increasingly acknowledged due to their capability of removing toxic ions at lower concentrations which are common in aquaculture effluent. Contaminants in aquaculture effluent such as nitrate and nitrate can promote eutrophication of receiving waters and be potentially toxic to aquatic life. These systems are still in their infancy and there is not enough information in this regard. Present study aimed to have more insight into the effects of different ambient pHs (6, 6.5, 7, 7.5 and 8) and temperatures (10, 15 and 20 C) on the ion adsorption capability of modified zeolite. To this end, zeolite obtained from the Semnan, located in the center of Iran, was modified using tetradecyltrimethylamonium bromide (TDTMA) and exposed to effluent from a fish culturing facility. ANOVA revealed that temperature had a well–arranged effect on nitrate and nitrite removal by modified zeolite compared with pH. Zeolite significantly showed higher nitrate and nitrite removal capacity at 15°C (p<0.05). However, pH had not any significant effects on nitrate removal (p>0.05). However, higher nitrite uptake was observed at pH= 6 and ph=8 (p<0.05). To devise an efficient zeolite based removal filters special for aquaculture effluents, more studies are needed in future.<\div>

۲Removal of anions from aquaculture effluent by Organozeolite
اطلاعات انتشار: دومین کنفرانس بین المللی زئولیت ایران، سال
تعداد صفحات: ۴
Synthetic and natural zeolites have become increasingly important in the last 30 years due to their wide range of physiochemical properties that make them capable of removing toxic ions at lower concentrations which are common in aquaculture effluents. Natural zeolites can remove ammonia from ambient aquaculture wastewater. At the present study the natural zeolite was characterized using XRD and XRF analyses. For removing anions from solutions and aquaculture effluent, modification was practiced with tetradecyletremethyleammoniumbromid (TDTMA) to increase the adsorption of anions (on the zeolite), which subsequently increase the ion absorption capacity of zeolite per se. Under the experimental and a standard solutions the effects of pH and temperature was evaluated. Results showed that increasing pH promote anion absorption (except for phosphate in standard condition). Like pH, temperature has good effect on the anion absorption. Results indicated that absorption active layer (Surfactant) has good tendency for absorption of nitrate ions. Results showed that clinoptilolite treated with TDTMA (SMZ) was efficient in removing undesirable anions from aquaculture wastewaters.<\div>

۳Body shape changes during the early development of the Beluga (Huso huso)
اطلاعات انتشار: International Journal of Aquatic Biology، اول،شماره۱، Feb ۲۰۱۳، سال
تعداد صفحات: ۵
Early body shape changes of beluga sturgeon (Huso huso) were studied using landmark–based geometric morphometric approach to recognize its allometric growth pattern. Sampling was done from hatching up to 50 days post hatching (DPH). Left side of specimens were photographed using digital camera and nine landmark points were digitized on two–dimensional images. Total length (TI) was measured using the software ImageJ. To study of the body shape changes during early development, the mean procrustes distance between all specimens of same age, for all age groups, was calculated. The scores of relative warp analysis (RW) were used as descriptors for the variation in shape. RW analysis revealed a sharp body shape change during early ontogeny on 18 DPH. Growth trajectory was computed by plotting RW against TL. The inflection point of body shape corresponds to a TL of 23.3 mm (18 DPH). Results showed that ontogenetic shape changes encompassed a pre–inflection shape changes, which included the elongation of the head and tail regions i.e. positive allometric growth pattern and post–inflection shape changes, with a nearly isometric growth pattern.

۴Effects of different photoperiods on the survival and growth of beluga sturgeon (huso huso) larvae
اطلاعات انتشار: International Journal of Aquatic Biology، اول،شماره۱، Feb ۲۰۱۳، سال
تعداد صفحات: ۶
Effect of different photoperiodic regimes was evaluated on growth performance and survival rate of the Beluga (Huso huso) prelarvae and larvae. Newly hatched prelarvae were stored in 5 round fiberglass 500 L tank with different photoperiod (24L:00D, 18L:06D, 12L:12D, 06L:18 D, 00L:24D) till 50 days post hatch with three replicates. Light intensity was 200 lux during the experiment. Feeding was started from 8 days post hatch using live artemia nauplii. Higher total length, survival rates and lower body area, yolk area for beluga prelarvae obtained in long light photoperiods (24L:00D, 18L:06D). Also, higher growth parameters of the beluga larvae observed in long light photoperiods while different photoperiods had no effect on survival rate. The present study indicated that growth performance and survival rates of larvae are significantly influenced by photoperiod. The photoperiod 18L:06D resulted in the best growth performance and survival rate during early development of the beluga.

۵Simultaneous detection of Aeromonas hydrophila, and Escherichia coli in Rainbow trout (Oncorhynchus mykiss) by Duplex PCR
اطلاعات انتشار: International Journal of Aquatic Biology، سوم،شماره۱، Feb ۲۰۱۵، سال
تعداد صفحات: ۸
Rapid and accurate identification of microorganisms have a significant impact on strategies and fish health management programs. Hence, in this study a duplex PCR assay based on the 16s rRNA gene for simultaneous detection of Aeromonas hydrophila RTICC 1032 and Escherichia coli RTICC 2325 from pure cultures, and challenged fish tissues was performed and their results were compared with the results of single PCR assays for each bacterium. For this purpose, an experiment with three treatments including artificially infected with A. hydrophila, E. coli and a mixture of them with a control group was designed. Fish were injected intraperitoneally with 1 ml of sterile physiological saline containing 106CFU\ml of the corresponding bacteria. Samples were collected from liver, kidney and spleen 48 hrs post–injection. A duplex PCR based 16S rRNA genes was developed for the simultaneous detection of A. hydrophila and E. coli. The PCR reaction conditions were optimized to permit detection of organisms from agar plates and fish tissues in less than 8 hrs. Each of the two pairs of oligonucleotide primers exclusively targeted 16S rRNA gene of the specific microorganism. When duplex PCR assay was used to simultaneous detection of the pathogens in asymptomatic fish, spleen and liver were negative for A. hydrophila, whereas kidney was positive for two bacteria. Samples that were duplex PCR negative were also negative by the culture method. On the whole, the duplex PCR has advantages in terms of its accuracy, sensitivity, ease of use, time of length analysis and cost–effectiveness compared to the single PCR and traditional method.

۶Hydrocortisone treatment may enhance survival and stocking of Beluga sturgeon (Huso huso Linnaeus, 1758) in estuaries of the Caspian Sea
اطلاعات انتشار: International Journal of Aquatic Biology، سوم،شماره۳، Jun ۲۰۱۵، سال
تعداد صفحات: ۶
Beluga sturgeon (Huso huso Linnaeus, 1758) fingerlings are released into the Caspian Sea for recruiting and enhancing commercial and recreational fishing purposes. These fingerlings are reared in fresh water, but released to the estuaries that may be caused mortalities due to acute osmotic stress. In this study, the fingerlings in whole (in vivo) or their gill tissue (in vitro) were exposed to three different levels of ‘the stress hormone’ cortisol (3, 5, 7 mg L–1 hydrocortisone sodium phosphate) for 24 hrs. The effects of treatments on blood cortisol levels and the size and numbers of gill chloride cells were monitored. In each case, hormonal treatment significantly increased blood cortisol levels and also the number but decreased the size of the chloride cells. We conclude that bathing in hydrocortisone could promote the survival rate of the fingerlings in brackish water and may be have a positive effect on their osmoregulation potentiality.
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