NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2014 | Volume:8 | Issue:3 |Papers Count:18

The study of Nannochloropsis oculata & Isochrysis galbana algae increase the percentage of unsaturated fatty acids, especially EPA and DHA fatty acids in Urmia Artemia (Artemia urmiana) was performed. Groups of 10-15 liters salinity, temperature in 25-26 ° C, pH 5 / 8-8, 2000 lux light) with emphasis EPA and DHA, on the study and with control group (Group of hunger during the treatments enrichment), were compared. The results show that the best time Artemia nauplii for enrichment with algae about 2 hours after the yolk sac is absorbed. The best species of algae to increase the EPA was Isochrysis galbana with the 1. 74 mg / g dry weight and increase DHA algae Nannochloropsis oculata with the 0. 22mg/ g dry weight and ratio between DHA / EPA is: 0. 12. The examples above that of the control sample is statistically significant.

The comparison of different light intensity effect on the cysts hatching ability of Artemia urmiana and Artemia franciscana

The study done in 1387 to determine the growth and survival rates Labeo rohita, Catla catla and Cirrhinus mirgala) in Khuozestan Province. 10500 of the juveniles fry were introduced to 3 pools by densty 3500 pieces per pool with combination 7. 46% of Catla catla, 35% Labeo rohita and 3. 18% Cirrhinus mirgala were. Mean of weight and total length of primary samples was 0. 3± 0. 0 g and 23. 6± 0. 75 mm of Labeo rohita, 0. 1± 0. 0 g and 33. 26± 0. 35 mm of Catla catla and 0. 16± 0. 01 g and 34. 8± 0. 96 mm of Cirrhinus mirgala. The results showed that the number of juveniles of the end of period at the pools numbers 1, 2 and 3, respectively, 3215, 3350 and 2812 survival rates at pools, respectively, 91. 85%, 95. 91% and 80. 6%. The results showed that the correlation coefficient between the weighted length of juveniles of three fish species Labeo rohita (R=0. 997, y=3E-06X3. 2511), Catla catla (R=0. 989, y=3E-06X3. 338) and Cirrhinus mirgala (R=0. 995, y=1E-05X2. 9583) are positively and linearly, so that the relationship was over 90%. According to the Pauli y test the length of fisheswere significant difference and the growth pattern was positive Allometric.

Because of the scarcity of fresh water resources in the country, the use of brackish and saline water resources for fisheries products is taken into consideration. In this study, growth rainbow trout with brackish water (14 ppt) extracted from underground water sources in the area Esferayen (North Khorasan) in earthen ponds with an area of 3000 square meters with a good depth of 1. 8 m was studied. The period of pisciculture were160 days (autumn and winter). The number of primary fish stock in each earth pond was 23000 and average weight of fish 22. 7 ± 1. 5 g. At the end of rearing period, because of differences in the survival rate of fish in pond1 (82%) and 2 (88%), differences in other parameters were significant (P<0. 05). So that in pond of 1 and 2 were determined FE: 0. 88± 0. 02, 0. 82± 0. 02; CF: 1. 42± 0. 01, 1. 29± 0. 03; SGR: 1. 51± 0. 01, 1. 40± 0. 02% /day-1; PER: 2. 26± 0. 05, 2. 11± 0. 06; FCR: 1. 18± 0. 02, 1. 25± 0. 04 and FW: 390± 7, 340± 7 g. respectively. The results showed that, Oncorhynchus mykiss fingerling have good growth in each pond with brackish water, whereas have difference relative in growth indicator.

Given the importance of sturgeon species and the sharp decline in reserves, recognition causes of mortality in this fish, to implement appropriate strategies, in order to cope with eventual mortality appears to be essential. Therefore, over a period during 2010 to 2012 causes of mortality Huso huso and Acipencer nudiventris in the sturgeon culture center in Mazandaran province were studied. During this period study, 2 sporadically mortality with symptoms such as: hemorrhage in gills, visceral organs, base of fins and ventral surface was observed. The results of bacterial culture and biochemical tests in both cases, confirmed the presence of Aeromonas hydrophila, necessary practices was took, that leading control of mortality and disease.

Effect of dietary betain as a food attractant on growth, survival, body composition and resistance to stress in Caspian roach (Rutilus rutilus) were investigated for 8 weeks. 240 individuals of Caspian roach by the weight of 6. 23± 0. 23 g and density of 20/tank fed in fiberglass tanks. Four treatments of different levels of betain including 0 (control), 0. 5, 1. 0 and 1. 5 percent added to diet (contained 41. 13% protein and 8. 42% fat). At the end of the study, growth and feeding factors including final weight, weight gain, feed conversion ratio, specific growth rate, survival rate, body composition and resistance to environmental stressors including thermal (40 oC), alkalinity (pH=12), acidity (pH=2) and salinity stress (150 g/lit) were assessed. According to the results, there were no significant differences in growth, feeding parameters and survival rate between fish fed control and betain supplementation diets (P>0. 05). No significance difference was observed in lipid and ash carcass (P>0. 05), but the highest of carcass protein was obtained in 1% betain (P<0. 05). The longest surviving time against thermal stress (P>0. 05) and acidity stress (P<0. 05) were due to 1% of betain and highest rate in salinity stress was due to control (P<0. 05) and highest survival rate after alkalinity stress was due to 0. 5% betafin (P<0. 05). Totally considering no significant differences in most parameters betain is not recommended to improve the growth, surviving and resistance to stress in roach juveniles.

In this study effects of ascorbic acid anti oxidant treatment (1, 2 and 5%) on ω 3 and ω 6 fatty acid changes on shelf life of Alosa caspia caspia fillets during frozen storage at-18 oC were examined. Twelve fatty acids were found in Alosa caspia caspia fresh fillets oil that results showed that the level of unsaturated fatty acid and saturated fatty acid were 48. 73% and 36. 87% of the total fatty acid. Palmitic acid (16: 0) was the dominant fatty acid, followed by oleic acid (18: 1n-9), DHA (22: 6n-3), with percentages of 23. 57%, 22. 41%, and 12. 16%, respectively. Ratio of ω 3/ω 6 at control sample was 4. 2% percent. Ratio of ω 3/ω 6 at Fillets have antioxidant 1, 2 and 5% after 120 days, respectively, 2. 03, 2. 11 and 2. 16 percent. Changes in polyunsaturated fatty acids in fresh samples and control samples containing 1, 2 and 5% of antioxidants significantly different percent P<0. 05. Based on the results observed with concentrations of 5% ascorbic acid to prevent lipid oxidation in fish fillets immersion (Alosa caspia caspia) during the period of freezing is recommended.

In order to assess the viability of rearing an Indian carp species (Crirhinus cirrhosus) under the climatic conditions in the northern part of Iran and to achieve some growth parameters from the larval stage to fingerling, measures were taken to import juveniles of the exotic species, from India and cultivate them in earthen ponds in Shahid Ansari production and propagation centre located in Gilan province. The fry of 180 mg weight and 23 mm average length were released into two ponds at a density of 50 fry per m2. Monthly fry samples were taken, for weight and length biometrical analysis and also determination of the weight gain percentage, average daily growth rate, specific growth rate and Condition Factor. Results have indicated considerable growth in this species, with an increase from the initial weight of 180 mg to an average of 46. 3± 3. 8 mg in 210 days period until the end of November. Average length of 16. 7± 0. 9 was also achieved at the end of the course. The Mrigal's weight-length correlation was defined in an function, from which b Index was obtained equal to 2. 723 which reveals an isometric growth in this specie. Studying the Condition Factor of the fry in the 7-month course of the experiment shows a decreasing trend in this index (from 2. 3 to 2. 1). Average daily growth (ADG) in the fingerling has also been foreboding of fluctuations in this period, being 0. 57 g in Aug., 0. 39 g in Sep. and in the last months 0. 13g in Dec. and 0. 5 g in Jan. The specific growth rate (SGR) in Mrigal fingerling in the 7 months was 2. 3% as an average, this index has shown a declining trend in the whole period and has fallen to 4. 6% in Sep and down to 0. 06% in Jan. The weight gain rate has also been estimated at 14842 % during this period. Results revealed that the Mrigal fry's compatibility with the condition in the Gilan province in the warm months of the year, but a growth reduction and a mycosis break-out was observed with decrease in the water temperature.

Stroeid hormones, progesterone both have very important role in controling of reproduction and sexual maturity of fish. This survey aimed to investigate changes in Stroeid hormones progesterone in female of Labeo rohita during years of 2011 to 2012 in different seasons climatic from Khuzestan province. In order to determine the amount of sex hormones in plasma samples 40 fish-breeding of Labeo rohita (1200± 80 g) was carried out they were stocked in three 1700 m2 each earthen ponds with the sexual ratio 1: 1. In each season blood was collected from 10 Labeo rohita (from caudal pedacle) then hormons was assess the with radioimmunoassay method (RIA). Mean of weight of fishes in spring, summer, autumn and winter were 1207. 5± 69. 58, 2464± 387. 01, 2718± 378. 42 and 2511. 25± 102. 5 g. The concentration of progesterone in female fishes in spring, summer, autumn and winter were 0. 27± 0. 04, 0. 16± 0. 02, 0. 86± 0. 01 and 0. 56± 0. 05 ng ml-1 respectively (P<0. 001). The highest and lowest of progesterone were in autumn and summer of Labeo rohita (P<0. 001).

Rainbow trout farmed fish is one of the most critical situation is in the early stages of growth. In this study, the cell wall of yeast Saccharomyces cerevisia added prebiotic dietary factors at different levels of immunity and intestinal bacterial flora were used. In the study, 120 rainbow trout fry with the average weight of 3. 61± 0. 12 gr containing 100 liters volume fiberglass tub were randomly distributed into 12 tanks and were reared. An experiment to determine the optimum level of prebiotic effect of dietary yeast cell wall in the diet of rainbow trout fry in 1% prebiotic treatments, 1. 5% prebiotic, 2% prebiotic prebiotic-free control, in a balanced design with three replications each were studied. The results showed that non-specific immune parameters in blood, such as lysozyme and specific immune such as IgM and Ig had statistically significant difference between treatment groups fed with 2% prebiotic yeast cell wall with other treatments and controls (P<0. 05). The intestinal bacterial flora of fishes on MRS agar and TSA were no significant differences between treatment (P>0. 05). But in the mean bacterial count was treated with 2% higher than the control and other treatments. Therefore, based on these results it can be stated that the level of 2% prebiotic cell wall of yeast used in the diet caused a significant increase in bacterial flora and immune parameters studied, an important role in the safety of rainbow trout fry plays.

The pomfret (Pampus argenteus) is a popular fish in the Persian Gulf. In this research, proximate composition and fatty acid contents of the pomfret fillets and their changes during frozen storage (-18  C) were investigated for 6 months. Moisture, ash, fat and protein concentrations were 78. 03, 1. 98, 7. 78 and 15. 41% in fresh fillets, respectively. Then, these contents were changed to 76. 40, 1. 12, 8. 76 and 14. 73% after 6 months of frozen storage, respectively. The saturated, monounsaturated and polyunsaturated fatty acids were 53. 13, 34. 31 and 11. 28% of the total fatty acids, respectively and changed to 54. 55, 33. 89 and 9. 09% in the 6th month of storage. The results show that pomfret muscle is rich in n-3 PUFA. Sothat, the ratio of n3/n6 PUFAs, was 6. 08 in fresh muscle and changed to 6. 25 after 6 months of storage. Also, the changes of proximate composition and fatty acid contents of pomfret fillets indicate that-18  C is an appropriate temperature for frozen storage.

Saline solutions containing cations (Na+, K+, Ca+2, Mg+2) were used to investigate the effect of ions on motility characteristics of spermatozoa (sperm movement duration and percentage of motile spermatozoa) and frtilizing capacity of sperm (fertilization rate, hatching rate, larvae length during hatching, larvae length during active feeding and survival rate) in Ctenopharyngodon idella. To survey of the effects of ions on sperm motility, Na+ (NaCl) (2208, 2393 and 2576 mg/L), K+ (KCl) (1200, 1400 and 1800 mg/L), Mg2+ (MgCl2) (132, 228 and 324 mg/L) and Ca2+ (CaCl2) (1000, 1200 and 1400 mg/L) were used. The results showed that, the highest duration of sperm motility and fertilization rate were obtained in solutions containing 2393 and 2576 ml-1 NaCl (P<0. 05), respectively. Solutions containing different doses of KCl caused a decrease in percentage of motile spermatozoa, fertilization and hatching rates (P<0. 05). The duration of sperm motility decreased in solution containing MgCl2 and immediately after activating by 1200 mgl-1 CaCl2 motility was ceased. Highest hatching rate (80± 5 mg/L), survival rate (92. 29± 0. 91 mg/L) were observed in solution containing 1000 mgl-1 CaCl2. With regard to our results can be conclude that NaCl and CaCl2 are influencing factors involved in fertilizing capacity of grass carp.

Giant gourami could be proposed potentially as a suitable species for rearing in Iran. But there is no information about chemical composition and fillet quality of this animal before and after cooking procedure, while this information is so useful to process it. In this study, effects of different cooking methods (steaming and grilling) on chemical composition, texture and fillet color of Giant gourami were investigated. Results showed an increase in protein content and a decrease in weight after cooking, moisture and lipid content was observed after steaming method, while grilling caused the decreasing of moisture and weight after cooking and increasing of lipid, protein and ash content (P<0. 05). Also two cooking methods histologically caused the increasing of cohesiveness, adhesiveness and springiness and decreasing of hardness in comparison to the raw fillet (P<0. 05). A decreasing of lightness and tendency to the orange and yellowness hue and significant increasing in ECI value was found in grilled samples, while steaming caused the lower redness hue. Finally the results of this experiment confirmed that cooking could improve the nutritional value of the foods and also represent information about rheological properties of Giant gourami flesh before and after cooking process.