NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2012 | Volume:6 | Issue:2 (22)|Papers Count:14

Nowadays, aquaculture has an important role to supply of white proteins in the world. Water quality and its control is the most important factor in the fish farming. It has been stated that a successful fish culture is affected by chemical equality of water. There are many fish farms and large natural ponds in the northern region of Iran, in Mazandaran specially, where is one of the most important provinces for warm-water fish culture such as Cyprinidae. In the present study Hydro-chemical parameters, have studied in two natural ponds and the factors were compared together and with standard conditions too. These two ponds are located in east and west of Mazandaran province, Iran. At the present research two natural ponds-Kooseh-Abband in Babol city (west) and Sarabbandan in Sari city (east)-have studied in culture seasons of spring and summer. The areas were almost 200 hectares both ponds. No fish stocking in ponds were made. Hydro-chemical and physio-chemical parameters such as Alkalinity, T.D.S, EC, pH, DO (dissolved oxygen), BOD5, COD, Nitrite, Nitrate, Ammonia ion, Phosphate, and N.T.U or water transparence, some heavy metals include Pb, Fe2+ and Zn and also water and weather temperature were evaluated using standard methods. The results were subjected and compared to Standards of water quality for fish culture. The results showed that amount of most parameters were found at the optimum range in the both ponds, but some observed parameters were out of optimum range, because there was not any fishery and environmental management there. Fish farmers can’t modify water quality very much in the natural ponds, but they can control the mentioned parameters in above. The amounts of some physio-chemical factors and heavy metals are affected by in-put waters and kind of bottom of ponds. The results also, showed that ecosystems are partly stable in both ponds and there are normal conditions to farming of Cyprinids fish, but it may be better. The fish farmers will have a successful aquaculture using monitoring and controlling of hydro-chemical factors.

Present situations of Sturgeon fish led to perform perfect attempt for restocking and preventing from extinction. This study was carried out in Shahid Marjani’s Sturgeon Breeding and Propagation Center during March-April in 2007. 46 breeders of Caspian sturgeon have been divided into 6 separated groups. After selecting of good breeders, the hormonal injection was performed in two sections for artificial provocation. After breeders’ ripeness, morphological and meristic parameters including weight, total length, standard length, age and girth were measured. Artificial propagation parameters such as egg weight, number of egg per gram, absolute fecundity, fertilization percentage, larvae weight and larvae survival rate were determined contemporarily. Obtained results show no significant differences (P>0.05) in measured parameters in each series. Relationships between variables were investigated by Regression analysis. Therefore significant correlations have been detected between weight, total length, standard length and girth with fecundity and egg weight (P<0.05). Furthermore, breeders ages were shown a significant relationship with egg weight (P<0.05). Fish ages do not show any relationships with other sexual factors. The time of ripeness indicates a significant correlation with length, weight and girth of breeders as well (P<0.05). Hatching rate and survival percentage of larvae have been also discussed in this manuscript.

The present study investigated 4 ponds of Acipencer fries. Raising period was 24-35 days. Physical, chemical analyses, water composition analysis, biological zooplankton biomass and benthos were conducted for each pond and period. The data showed a significant difference among temperature, pH, total alkalinity and nitrate. There was not a significant difference between oxygen factors and carbonate in the ponds. Zooplankton production consisted of Daphnia, Cyclopes a Nauplios of Cyclopes, with the Cyclopes as the most prevalent. The minimum and maximum zooplankton biomasses in the ponds were 2.8-5.8 gr/m3 respectively. In a benthic biomass analyses, compared to different kinds of organisms, Chironomous was the most prevalent with a minimum of 0.159 gr/m2, and a maximum of 0.194 gr/m2.

Mullet transferred to the Caspian Sea in 1930 from the Black Sea. This is possible over 80 years of adapting to the conditions of the Caspian Sea, to change some of morphology features. This study aimed to compare the above characteristics with their fellow Black Sea and changes in the new environment has been adaptation. The study designed with objective on study morphometric and meristic characteristics of golden mullet (Liza aurata). 98 specimens were collected from catch of beach seine in the southern part of Caspian Sea. The mean body fork length, weight were measured 310.1±40.5 mm and 310.3±146.2 g, respectively. According to exponential length-weight relationship, growth followed isometric model (b=3.01). The mean age of golden mullet was 5.75 years (range 4-8 years). Statistical analysis of variance revealed significant differences between the means of samples for the number of second dorsal fin spines and also the number of anal fin spines in males and females (P<0.05). The comparison of the results obtained in the Azerbaijan with this study indicates differentiation and geographical separation between these stocks in the most morphometric features and meristic counts.

An 8-week experiment was conducted on the to effects of dietary Immunogen prebiotic and Protexin probiotic on growth indices and survival of Astacus leptodactylus. This experiment was done with two treatments, including of trade probiotic (Protexin) in levels 1 and 3 g/kg in food, and a kind of prebiotics with trade name of Immunogen prebiotic in levels 2 and 4 g/kg in food, and control group without probiotic and prebiotic and three replication for each of them with energy 4500 cal/gr and with 40 percent protein and 7 percent lipid. 120 crayfish with an average individual weight of 23.05±0.74 gram were selected and randomly stocked into the 15 fiberglass tanks of 100 liter capacity and tanks were filled with 70 liter freshwater and approximately 30% of the total water volume was replaced daily with freshwater. The experimental Cray fish were fed with diet pellet 1 once a day according to 3% of body weight at 5:00 pm. the results showed with adding probiotic and prebiotic in experimental dietary, such growth indices of crayfish as weight gain, mean daily growth, specific growth rate, food conversion ratio, protein efficiency rate were improved as there are statistical significant differences among treatment with 3 g/kg probiotic and control diet (P<0.05). Also the mentioned growth indices in treatment 2 g/kg rather than control was better but there were no significant differences among treatments. Statistical survey represents there were no significant different factors of coefficient condition and survival rate in crayfish among treatments (P>0.05). The results indicated that Protexin probiotic and Immunogen prebiotic can effect on growth indices in Astacus leptodactylus and in all of the levels the most effective content were levels of 3 g/kg probiotic in probiotic treatment and in the prebiotic treatments, the best level was 2 g/kg prebiotic in dry food.

The Abramis brama orientalis is a commercially valuable species distributed in the Iranian shores of the Caspian Sea, particularly in the coasts of the Gilan province, Anzali Wetland and in the lake behind the Aras Dam. Changes in environmental conditions and occurrence of disease are associated with changes in some hematological parameters. The effects of parasitical infection on hematological parameters in 175 Abramis brama were studied during the fishing season for this species in 2008-2009. After fish catching and transporting to laboratory, different organs like eye, skin, gill and digest system surveyed. In this study, average length (28.67±2.86 cm) and average weight (298.18±62.74 g) were. Based on studies 4 parasite species: Diplostomum spathaceum, Trichodina sp., Ligula intestinalis and Caryophyllaeus laticeps introduced. According to results, maximum outbreak (73%), average frequency (1.84 pieces) related to Ligula intestinali, maximum average virulence (3.96 pieces) related to Caryophyllaeus laticeps and minimum outbreak (22%) belonged to Diplastomum spathaceum and Caryophyllaeus laticeps, minimum average virulence (2.06 pieces) belonged to Diplastomum spathaceum, minimum average frequency (0.45 pieces) Caryophyllaeus laticeps and parasite number amplitude (1-6 pieces) were related to 4 parasite species.  

In this study three-dimensional modeling of flow patterns in the South East Caspian sea Area by using Mike 3 software has been studied. In order to Imposing open boundary conditions in western and northern borders of the solution domain, the results of two-dimensional Mike 21 model in the Caspian sea includes velocity components and water level fluctuations have been used. In the implementation of Mike 21 model, wind data obtained from the numerical atmospheric model provided by NOAA site with resolution on the order of 2.5 degree and variable in space and time together with the effects of major rivers to the Caspian Sea (Volga, Terek, Sefidrud, Ural and Kura), bed friction, evaporation, Coriolis force And out flowing water from the Kara-Bogaz-Gol Bay is considered. Dimensions of the solution domain in the South East Caspian sea covered by 60×90 square grid with sides of 1000 m and with 17 vertical layers. In the implementation of Mike 3 model in order to applying effect of Wind, data of Bandartorkman Synoptic station after conversion to offshore wind together with major rivers input (Atrak and Gorganrood), water exchange with the Gorgan Bay, bed friction, evaporation and Coriolis force was used. In order to validate the results of the model, outputs of the model are compared with field measurements and demonstrate the ability and accuracy of the mike 3 model in simulation of sea currents. Flow pattern obtained from the model to explain long shore currents in the coastal beach and two current gyres is in the middle layer. By Moving towards Deep area, currents go out from the solve area with the 180 degrees of phase difference from surface currents.

The color rearing tanks is an important factor that can attract fish meal may have to use it to fish growth and survival is greater. This experiment was conducted for 8 weeks in the center propagation of fish bone in Syjuval, Bandar Turkman, Golestan province. The tests conducted on 5 treatments and 3 replications were as follows: treatment, 1: red tank, treatment, 2: blue tanks, treatment 3: white tanks, treatment 4: black tanks. Feeding rate was 10% of total body weight of fingerlings. Physical and chemical factors were so controlled through the experiment that the amount of dissolved oxygen was fixed on 5.75±0.25 ppm, the temperature 26±2oC and pH 7.75±0.25. Rutilus rutilus caspicus were fed during the experimental period with SFC foods containing: 8.7% moisture, 11.2% ash, 32% protein and 10.5% fat. According to the results of this study, it was shown that various color tanks affect body weight and length gain of fish and these differences are significant (P<0.05). Maximum weight and length of body was in treatment 4 with black. Results also showed that there is significant difference in the rate of SGR, BWI%, GR and CF (P<0.05). However, there were no significant differences with regard to the amount of FCR and survival (P>0.05). This study showed that use of black tanks make better growth in R. r. caspicus.

This study represents a larg-scale population genetic analysis of the stellate sturgeon in the Northern (Ural River) and Southern Caspian Sea (estuary of Sefidrud and Gorganrod Rivers-Iran). Totally, 138 individuals of adult stellate sturgeon from three regions were sampled. Fifteen sets of microsatellite primers were developed from lake sturgeon (Acipenser fulvescens) and shovelnose sturgeon (Scaphirhynchus platorynchus) tested on genomic DNA of stellate sturgeon. Allele frequencies, private alleles, observed and expected heterozygosity, Hardy-Wienberg Equilibrium, genetic similarity and distance, FST and RST based on AMOVA were calculated using the Gene Alex software. At this point, the ten successfully used primer sets should be mentioned and polymorphism was observed, while one locus was monomorph and four sets didnt. Analyses revealed that average of alleles per locus was 12.7 (range 8 to 18 alleles per locus in regions). All sampled regions contained private alleles. Average observed and expected heterozygosity were 0.651 and 0.85 respectively. Basis on AMOVA for all FST values among pairs of collections ranged between 0.047 to 0.058 and indicated a significant difference between the three geogeraphic regions (P<0.01). The genetic distance between populations based on Nei (1972) index, was 0.421 (±0.08), which indicates that the genetic difference among populations is pronounced. These results together with highly significant RST of genotypic differences between these pairs of collections support the existence of different genetic populations along the Caspian Sea coast.

Effects of dietary mannan oligosaccharides (MOS) on growth, survival and body composition of Litopenaeus vannamei were evaluated. Litopenaeus vannamei juvenile with an average weight of 2.5±0.12 g was stocked in fiberglass tank at a rate of 25 shrimp per tank and reared for 51 days. Experimental diets were prepared by using supplementation of 0 (Control), 1.5, 3.0 and 4.5 g MOS kg-1 commercial shrimp diet containing 38.7% protein and 3.85% lipid. At the end of the study, generally enhanced growth performance and feed efficiency were observed in shrimp fed on diet containing 3.0 g kg-1 MOS (P<0.05). There were no significant different in survival between treatments (P>0.05). The protein contents in the whole body increased with increasing rates of dietary MOS. In conclusion, 3.0 g kg MOS could be used as a healthy growth promoter in shrimp diets.

Polychaets are the group of macrobenthos and because of high species richness and diversity in ecosystem, exist in the varieties bed and habitats and play a significant role in food chain, many of ecologists in the whole of world attend them. In order to identification polychaets and determine their distribution in Bahrakan shore, samples of sediment were collected from 5 different stations in autumn and spring seasons. The samples after transferring to laboratory, were sieved using. 5 mm mesh size sieve. After washing and coloring with Rous Bengal, polychaets identified as far as possible genus or species. Physico-chemical parameter was mesured. Ecological indices for diversity, dominance, richness and evenness were calculated. Families of Syllidae and Cossuridae constituted 55% and 25% of total polychaets respectively in the autumn. On the other hand families of Nephtyidae, Syllidae and Glyceridae in the spring constituted 28%, 24% and 14% of total polychaets in the sediment respectly. At spring, polychaets have maximum density (2121 I/m2) and at autemn they have minimum density (1853 I/m2). Food increasing and vulnerable environmental conditions in spring was cased of increasing spices. Polychaets diversity in muddy shore of Bahrakan was decrease comparing to other shore. But polychaets diversity was increase comparing to pervious studies. Suggesting that building of artificial reefs case increase of diversity.