NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2011 | Volume:5 | Issue:1 (17)|Papers Count:15

Considering the importance of Zooxanthellae in bleaching phenomenon, and in order to understand the correlation between Coral reefs and symbiosis algae in the Persian Gulf and strength of reefs against environmental conditions, Symbiotic algae were studied.Materials and Methods: Samples of coral species (Siderastrea savignyana, Coscinaraea columna, Anomastrea irregulariis, Cyphastrea serailia, and Psammocora superficialis) were collected from intertidal pools of Hengam Island in Iranian side of the Persian Gulf (south of Qeshm Island-Hormozgan province). Partial 28S nuclear ribosomal (nr) DNA of Symbiodinium were amplified by Polymerase Chain Reaction (PCR) and then PCR products were analyzed the phylogenetic analyses of the LSU DNA sequences based on PAUP and Clustal X software.Results: The results showed that there are at least two clades of Symbiodinium from Hengam Island corals, Clade D was detected from C. columna, A. irregulariis, C. serailia species while clade C just found in S. savignyana, P.superficialis.Conclusion: This study showed that the persistence of clade D and clade C Symbiodinium in Hengam Island is due to high environmental stresses in the intertidal pools.

Different N: P ratios and varying phosphorus concentrations were considered based on the logarithmic calculations and the effects of these factors on cyanobacterial bloom of Nostoc sp. were inspected. The study was performed in situ while the temperature and light intensity were kept at 25±2oC and 3500±350 lux respectively. The laboratory tests lasted 96 hours. Zinder media was used as the control medium however different N: P ratios and P concentrations were applied as treatments. Visual counting at the start and end of the experiments were carried out to assess the growth percentage. The results showed that phosphorus concentrations in Zinder media (2.96 mg.L) are the optimum value for Nostoc bloom. Nostoc achieved its optimum growth at the range of 2.5N: 1P to 10N:1P. The maximum level of growth percentage was reached to 3497.17±746.18 percent in 4N: 1P ratio with 11.84 mg.L of nitrogen and 2.96 mg.L of phosphorus. The bloom was eliminated at 145.27: 1. The whole results confirmed that in the presence of enough nitrogen and phosphorus concentrations with low N: P ratio, the maximum bloom intensity observes.

In this study, growth performance of rainbow trout by using two types of industrial wastes including waste grain processing by industry for bread and pasta as an alternative source of carbohydrate in grower diet, was studied in a completely randomized statistical design. Seven experimental diets were prepared. Amount of carbohydrate materials replacement in diets were: 1) 100% bread wastes 2) 50% bread wastes 3) 100% macaroni wastes 4) 50% macaroni wastes 5) 100% equal mix of bread and macaroni wastes and 6) 50% equal mix of bread and pasta wastes. Diets set by Lindo software. 21 polyethylene net cages (1×1×1 m) used for fish holding in a cement pond (30×3×1.2 m) with 10 l/s water flow. Each cage stoked by 20 fish with initial average weight of 85±5 g. Farming period was 75 days and in this period water temperature, pH and dissolved oxygen were 14.5±2°c, 7.5-8.8 and 6.8-8.5 mg/l, respectively. In this research some main growth equations (WG, PER, FCR, SGR, DP, CF) and economical factors were studied. Data were analyzed using SPSS software, Dankan analysis and also descriptive statistics. The best growth performance belonged to diet 4, although results diets of 2, 4, 6, and control no different (P<0.05). In term of economic value of used diets, diets 2 had the best result. Carcass analysis in the end of experiment showed that carcass protein and ash contents in all of treatment were same but lipid content in treatments of 1, 3, and 5 were lower than other treatments (P<0.05). Economic analysis showed the superiority of the two treatments in which 50% of wheat and corn was replaced by bread wastes. According to the results, the use of mixed pasta and bread wastes instead of 50% wheat brings about good results in terms of growth performance and lower cost than the control diet and is recommended in diet of trout in grower stage.

The short term influence of waterborne cadmium (Cd+2) on serum parameters related to bone metabolism including Calcium (Ca), Phosphorus (P) and Alkaline phosphatase (ALP) of Common Carp fish (Cyprinus Crarpio L.) were studied. Fish were treated with varying concentration of Cd+2(0.22, 1.1 and 2.2 mg L-1) with three replications for 14 consequent days. At the end of the experiment, three random fishes were kept from each aquarium. After that the fishes were anesthetized, then blood samples were withdrawn and sera were prepared. The results obtained showed that serum P and ALP concentration were elevated by increasing of Cd+2 doses; whereas the serum Ca levels was decreased significantly (P<0.05) by 27.7%, 36.8%, 98.9% in comparison to Control treatment. The role of Cd+2 on disturbances on serum parameters related to bone metabolism in this manuscript also discussed.

The objective of this study was to determine the best dose and time exposure of Maharloo Artemia cyst in sodium hypochlorite to achieve the highest hatchability rate in decapsulation process. After decapsulation, 2g cyct/L was exposed to 27ºC up to hatch for 24h. In the first experiment different doses of sodium hypochlorite include 8, 16, 24, 32 and 40 percent were used. The highest hatching percentage was observed in dose of 32 percent with 85.39±9% (P>0.05). In the second experiment, different time exposed to dose 32 percent of sodium hypochlorite including 0, 2, 4, 6, 8, 10, 12 and 14 minutes were studied. The best percentage hatching rate of 8 79.32±8 was achieved for 4 minutes (P<0.05). The results of this study suggest that putting Maharloo Artemia cyst in dose of 32 percent hypochlorite for 4 minutes can be reached to the best performance of hatchability for this species which could use for aquacultural purposes.

In the present research, in order to count red cells and study haematocrit and haemoglobin values in juveniles of Acipenser persicus and their changes in different photoperiods, 450 Persian sturgeon juveniles were used at five photoperiods: 24L:0D, 16L:8D, 12L:12D, 8L:16D and 0L:24D for 60 days. At the end of experiment, 3 fish randomly were selected from each replication of treatment and blood samples were taken from caudal fin of juveniles. The results showed that number of red blood cells (An average 516666.7±40242.3 per a cubic millimeter) were significantly in 0L: 24D photoperiod highly than other groups. Results also indicated that different photoperiods had no significantly effect on values of haemoglobin and haematocrit. The highest haematocrit and haemoglobin value was observed in the 16L: 8D and 12L: 12D photoperiods respectively.

This study was carried out to determine age and growth of large scaled barb (Barbus grypus) in Helle and Dalaki Rivers of Boushehr Province. In this research, 2494 fish were caught during 14 months sampling period. The most abundant length class was 200-300 mm. The most abundant ages were 2 and 3 years old. The most aged of fish was 8 years old with 765 mm length. Von bertalanfy growth equation showed that fishes in upstream stations have greater L∞ than downstream station. L∞ in male and female upstream fishes was 1245 and 1189, respectively. L∞ in male and female downstream fishes was 1120 and 1165, respectively. Condition factor showed that female fishes have better condition than male fishes and fishes in 6 and 7 stations have greater condition factor.

To carry out this study, 3000 Rainbow trout Fry’s (2-3gr) were sampled and divided into three trails (A, B and C) with 3 repeats in each trail (300 Fry’s in each repeat). Group A includes 3% diatomite, group B includes 2% diatomite and group C was without any additive matter. 30 Fries were selected randomly every 20 days one time and growth factors and survival rates were compared with each other. Fries were stored in 1m3 fiberglass tanks and then handled to concrete ponds. Results of growth factors and survival rates showed no significant differences in each group (P>0.05), but results of carcass chemical analysis showed a significant different in these groups (P<0.05), so that fat percentage in B group (0.87%) was lower than A (1.05%) and C (1.86%) group. An adverse relationship was observed between liver and muscle fat percentage in groups A and B. there was a significant difference in fat among each group, so that in B group was 7%, in a group was 6.28% and in C group was 4.67%. Muscle protein in C (18.47%) group was more than B (18.28%) and a (18.11%) groups. there was no significant difference between C group with A and B group in protein percentage. Basis on these results, the Diatomite has a noticeable effect on fat percentage of fish ration and carcass (liver and muscle) and it can be used for regulating of them.

Zabol has an annual mean rainfall less than 100 mm, so construction of cement reservoir pond for agricultural well (200 m2 area and 1.5 m depth) is necessary to make the best use of retail water resources. There are about 2170 agricultural tube wells in Zabol, which among them only 218 wells have cement dual purpose pond. With average fish production of 1/5 tones in dual purpose pond, Zabol has a potential of annual production of 2928 tones. The cultural duration for cold and warm water fishes in good climatic condition in Zabol is about 150 and 210 days, respectively. The average water temperature for cold and warm water fishes is 8 to 18 ºC and 20 to 30 ºC during fish culture, respectively. The total fish mortality in this system was low and about 5 %. The warm and cold water fish production was around 760 and 540 Kg per unit, respectively. The food conversion ratio was calculated about 25-30 for warm water fish and 1.3-1.4 for cold water fish, respectively. For warm water fish, the daily growth and specific growth rate was 4.71 and 1.87, respectively. For cold water fish, the daily growth and specific growth rate was 2.19 and 1.81, respectively. The gained at sale 570 kg and 760 kg profit of fish culture was around 19000000 Rials for warm water fish and 11400000 Rials for cold water fish per culture period. Fish culture in Reservoir pond can proves as cost effective practice for poor farmers in rural area and becomes a good way for protein supplying, increasing the irrigation efficiency, water fertilization and increasing the crop production in these area.

This study was carried out (2010) in the Shahid Beheshti Sturgeon Rearing and Propagation Center and International Sturgeon Research Institute (Rasht). For this research 11 wild male brood fish of Persian Sturgeon were used. Each broodfish received hormonal injection twice in 3-7days intervaland then sperm samples were stripped. Sperm from 6 brood fish used for second time were collected. The results showed that the mean rate of sperm motility in the first and second sperm stripping were 78.5±5.43% and 50.0±20.25% respectively. Also the mean duration of sperm motility in the first and second stripping were 315.83±162.16 and 212.5±110.53 seconds respectively. The mean sperm density in the first and second sperm stripping were 2.1±1.3×109 and 0.55±0.34×109/ml respectively and also the mean spermatocrit level in the first and second sperm stripping was 9.33±3.32 and 3.42%±3.35 respectively. Similarly mean sperm pH was 8.41±0.53 and 8.05±0.33 in the first and second stripping respectively. Based on results obtained rate of sperm motility, spermatocrit and sperm density were significantly different (P<0.05) between the two stages of sperm stripping. Despite of decrease in duration of sperm motility and sperm pH in the second stage of stripping, there was no significant difference (P>0.05) between the two repetitions.

In this study, biopsy was carried out on the gonads of Huso huso having 3 & 4 years old, reared in concrete ponds of Shahid Rajaii hatchery of Sari (50 species) and Shahid Marjani hatchery in Ag-Ghala (25 species). After biometry & recording of data, biopsy of gonads performed. All of the tissue sections stained by hematoxylin & Eosin, then specimens prepared and studied under light microscope connected to a camera and monitor. In female Huso huso of Shahid Marjani hatchery the mean diameter of oocytes were 385.3±73.6, 234.1±59.4 and 36±24.3 µm in stages III, II and I and the mean diameter of nucleus was 80.7±27.8, 63.8±10.8 and 14.5±10.5 µm in stages III, II and I, respectively that showed significant differences (P<0.05).The mean diameter of nucleus in stage III is higher compared to other two stages (P<0.05). In Shahid Rajaii hatchery (Sari), the mean diameter of oocytes in female Huso huso of 3 years old were 381.1±82.1 in stage III, 219.4±54.7 in stage II and 27.3±38.4 µm in stage I, which shows significant differences (P<0.05). Moreover, the mean diameter of nucleus was 75±50.4, 45.7±17.7 and 3.9±0.7 µm in stages III, II and I, respectively. Also, in four years old Huso huso, the mean diameter of oocytes in stage III were 186.1±36.2 µm which was higher than stage II, 120.1±43.4 µm. In addition, the mean diameter of nucleus in stage III of sexual maturity was 55.1±10.9 µm compared to stage II, 44.7±13.9 µm which indicates significant differences (P<0.05). The results showed that the age of examined fishes have not role on the size changes in oocytes and for a species, the size of female oocytes could be in an specific range for each stage of sexual maturity. Statistical analysis shows no significant differences in similar stages of sexual maturity in the fishes of these two hatcheries, too.

One of the important matters in aquaculture is achieve balance between rapid fish growth and optimum use of provided food. In culture kutum larval, feeding management is very important because suitable feeding in a good time can decrease survival and increase growth. This study was done with 5 treatments and 3 times repetition: Treatment A: two times feeding per day with SFK, Treatment B: one time feeding per day with mixture of SFK and fish powder (25% weight SFK), Treatment C: two times feeding per day with mixture of SFK and fish powder (25% weight SFK), Treatment D: three times feeding per day with mixture of SFK and fish powder (25% weight SFK), Treatment E: four times feeding per day with mixture of SFK and fish powder (25% weight SFK). In each treatment in this examination feeding regularity were 8,11,14,17 hours. It's necessary to note that rate of feeding is based on 15 percent of whole weight of larval body fishes on a day. Results indicated there was a significant difference between weight and length gain. Fish larval in control treat that was fed with SFK diet had the lowest weight and length and fish larval that was fed with the higher protein level had the most length and weight for four-time feeding per day.

There are several factors affecting Angel Fish frys (Pterophyllum scalare) survival and quality. In this study, the effect of diet on weight, length, specific growth rate index, weight growth and survival of Angel Fish fry have been studied. Food treatments include dry blood worm, Artemia encapsulated cyst and dry blood worm in addition to, Artemia decapsulated cyst. Three repetitions had to be done with each food diet. Thus 9 aquariums with 60×40×30 centimeter dimension were allocated for this treatment. Temperature of these aquariums was considered at 31 degree of centigrade and the others factors including the temperature pH and oxygen degree was fixed and similar for all treatments. Then degree of growth and survival of Angel fry was studied in 30 days. The result of this search has shown that growth and survival of Angel fry with dry blood worm in addition to Artemia decapsulated cyst has the best degree of growth in comparison to the other observed food diet and using the mean test between length, weight and survival percentage, it became known that there is significant difference between the kind of food treatments (P<0.05). for specific growth rate index and weight growth with dry blood worm has the best degree in comparison to the other observed diet and there is no significant between dry blood worm in addition Artemia decapsulated cyst treatment with dry blood worm (P>0.05).