NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2018 | Volume:11 | Issue:4 |Papers Count:9

Nonylphenols havecomprehensive usage in plastic, cleaning products, resins and stabilizers in industry and via sewage permeate to aquatic ecosystems. The study demonstrated the effects of the 4-nonylphenolon microsatellites in the prelarvae of the Iranian sturgeon (Acipenser persicus) as biomarkers to investigate their genetic diversity. 480 prelarvae of the Iranian sturgeon in the 4 treatments and 3 replications (two sublethal concentrations 40 and 70 μ g/l of the 4-nonylphenol, control and sham) was applied in the ten days three periods. The experiment was carried out semi-static condition. Evaluation genetic diversity of the prelarvae's Iranian sturgeon for four pairs of the microsatellites markers (AfuG68b, AfuG63, AfuG241 & LS-68) carried out in the above four concentrations. Finally, the minimum number of alleles observed were 2 (AfuG68b) and the maximum number of alleles observed were 4 (AfuG63) in the 70 μ g/l of the 4-nonylphenol. The minimum heterozygocity observed was 0. 733 (AfuG68b) and the maximum hetrozygocity observed was 1(AfuG241). The minimum hetrozygocity expected was 0. 511 (AfuG68b) and the maximum hetrozygocity expected was 0. 644 (AfuG63). At the fourtreatments, the medium hetrozygocity expected &hetrozygocity observed 0. 852 and 0. 583, respectively. The number of effective allels were increased in the 70 μ g/lat the AfuG63 locus than control. Therefore, the genetic diversity was increased in the environmental with 4-nonylphenol compounds.

In this research 47 genus of different phylum of phytoplanktons such as Cyanophyta, Chlorophyta, Pyrophyta, Chrysophyta and Euglenaphyta were surveyed that their numbers (ind. /m^3) and biomasses (mgr/m^3) were estimated. Frequncy of phytoplantons (ind. /m^3) was 131. 2, 1. 6, 65. 3, 18. 9 and 23. 8 million respectively. Furthermore, their biomasses was 08. 4, 1. 9, 1358. 9, 295. 1 and 124. 7 mgr/m^3, respectively. The maximum and minimum numbers were observed in Leptolingbaya belonged to Cyanophyta and diatoms of Chrysophyta 84. 3 and 0. 025 million ind. /m^3 respectively. The maximum and minimum biomass was observed in Gyrosigma (Chrysophyta) and Tetradron (Chlorophyta), 12317. 3 and 0. 014 mg/m^3 respectively.

The aim of this research is study the effects of freezing at-20 ◦ C after hydration and dehydration on the hatching, survival percentage and growth of Artemia urmiana cysts. Experiments were carried out in three treatments. In first treatment, hatching was done after one hydration and dehydration cycle with standard method. In second treatment, hatching was done after one hydration and dehydration cycle and then one week freezing at-20 ◦ C temperature. In third treatment, hatching was done after one hydration and dehydration cycle and then one month freezing at-20 ◦ C temperature. Standard hatching was done without any other treatment in Control group. Hatching percentage was determined with three replicates for each treatment by standard method. Survival and growth was measured and compared on days 8, 11, 15, 20 and 25 of growth. Results indicated the cyst hatching percentage increased regularly by increasing freezing time (one month freezing), even though hatching percentage was higher in control group. The most survival percentage was observed in 11th day of third treatment. Highest growth was in 15 to 25th day of third treatment (P<0. 05). To sum up, against some other species, hydration/dehydration and freezing is not necessary in Artemia urmiana and performing it decreases hatching percentage.

Vibrio is pathogen that spreads in the marine environment widely. These organisms are isolated from lots of raw sea food. Given that some Vibrio can cause disease in humans too, the consumption of raw and undercooked sea food contaminated with some Vibrio species, leading to acute gastroenteritis with clinical signs. This study aimed to determine the contamination Litopenaeus vannamei from one of the active farms of shrimp rearing in Bandar Deylam with emphasis on Vibrio cholerae. In total, 50 samples were captured from four farm’ s ponds and sent to Bacteriology Laboratory, Kazerun Branch. In order to performing bacteriological tests on homogenized shrimp and gill and hepatopancreas was used by inoculation on medium. For this purpose, at first samples were cultured on sea water agar (SWA) and were incubated for 24 hours. Then samples were cultured on the choice medium for Vibrio (TCBS). After 24 hours of incubation and growth of bacteria, Gram staininig and biochemical tests were performed for detection of Vibrio genus and species. The results of biochemical tests such as oxidase, catalase, motility, citrate, indole, H2S, fermentation of mannitol, sucrose, arabinose, glucose, cellobiose, TSI and growth on Nacl showed that Vibrio cholerae was not isolated from any any samples.

This project was carried out in order to study the effects of water chemistry on the accumulation of lead and cadmium in weight groups of farmed trout. For the chemical properties of water hardness, temperature and pH, and three weight groups consisting of large (700-900 g), medium (400-500 g) and small (300-0. 03 mg/kg. The levels of lead and cadmium in water and feed for farmed fish below the limit allowed by the FDA. These elements did not show significant differences in farmed trout (P>0. 05). Based on achieved results, pH and water temperature affected the infiltration of lead to the trout farm. But, hardness of water affected the infiltration of Cadmium to the trout farm.

Much interest is currently drawn to edible films, from proteins, polysaccharides, fats, or their combination. With a polymeric nature, gelatin has a good film-forming capability and replacing synthetic plastics with naturally degradable films is the perfect solution for minimizing undesirable and harmful effects of synthetic waste. The main problem is their fairly high hydrophilic and poor mechanical properties compared to conventional synthetic films. In the present study, films of fish gelatin with ratios of 15%, 10%, 5% and 20% to carboxy methyl cellulose were prepared by casting at 85 ° C. The effects of different concentrations of carboxy methyl cellulose on water vapor permeability (WVP), water absorption capacity (WAC) and solubility were assessed. The results obtained showed that increasing concentrations of carboxy methyl cellulose reduced WVP and increased WAC and solubility of gelatin films. Generally, the addition of carboxy methyl cellulose improves transparency and physicochemical properties of gelatin films, and facilitates the use of these biopolymers in packaging industries.

The present study was aimed to determine optimum concentration of nutrient nitrate on the growth of macro algae, Gracilaria corticata. The algae G. corticata collected from North Oman seat, in Chabaharʼ s coast in December 2017. For this purpose, fertilizer NaNo3 (10-40 mg/l) were used in four experimental treatments and one control group with three replicates during 50 days. Algae biometry done in days of 7, 14, 21, 28, 36, 42 and 50. At the end of fiftieth day of the experiment, the maximum of biomass increased from 5 ± 0 to 21. 59 ± 2. 74 g. In NaNo3 (10 mg/l) treatment, the maximum daily growth rate were observed at day 36 (%7. 61 ± 1. 34%) (P<0. 05). Results shows that algae’ s growth had increase relative from 21Th to 50Th in treatment 10 mg/l than others treatments. The biomass produced can be used for extract bioactive materials, pigments and agar extraction.

The use of natural extracts, one of the most suitable antioxidants increasing for improves the quality of fish, the aim of this study was to evaluate effects of green tea extract antioxidant on the quality of fish and minced of Silver carp that stored at the refrigerated temperature (4 oC). Samples were treated with green tea extract at a concentration of 1000 ppm, after the normal packaging was kept at a refrigerated temperature. The chemical and enzymatic indices of lipid degradation include peroxide, free fatty acids (FFA), thiobarbituric acid (TBARS), pH and Sensory performed at 0, 4, 8, 12 and 16 days, with 3 repetitions was evaluated and compared with blank sample. Results showed, green tea extract delayed oxidation at all test times significantly (P<0. 05) and the sensory evaluation results indicated a significant decrease in sensory properties of the fillets during the maintenance period. And the finally, In this study, fillet was used with 1000 ppm extracts up to the end of maintenance period better than comparison with other treatments.