20 research outputs found

    Zeolite application to sea water for ammonia absorbtion and its effects on growth and survival of Penaeus indicus

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    We evaluated Zeolite efficiency in absorption of ammonia from sea water. Three phases including ammonia movement through Zeolite column, application of Zeolite powder and granule in closed containers filled with ammonia solution and dispersion of Zeolite in shrimp culture tanks were implemented in the study. For the first phase, ammonia solution in two concentrations (4.8 and 2.42mg/lit) and a water salinity of 42ppt (sea water) was passed through the Zeolite column (400g of granule Clinoptilolite) in three replications. Concentration of ammonia in outlet solution was between 0.2-5.4mg/lit in the first replication and 0.0 to 5.5, 0.0 to 2.6mg/lit in the 2nd and 3rd replication, respectively. At the second phase, volume and levels of ammonia concentration left in the closed jug of ammonia solution was different. The concentration of ammonia was measured at various time periods in four replications. The results showed that ion exchange in seawater is not a one way process, so that ammonia concentrations in the jugs with Zeolite fluctuated with time, contrary to its stable concentration in control treatments. At the third phase, Zeolite in granule and powder forms was added to culture tanks of shrimp juveniles (Penaeus indicus) weighting on average 0.2g each for 79 days of culture period and a stocking density of 16 individuals per square meter. Thus, we provided three treatments, using Zeolite granules, powder and one control. A Duncan's test of the growth and survival rate of the cultured shrimps showed no significant difference among the treatments (P>0.01)

    Assessment of acute effects of Streptococcus faecium on some hematological and histopathological parameters in juveniles rainbow trout (Oncorhynchus mykiss)

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    Streptococcosis is one of the most important bacterial diseases in cold water fish because of its rapid outbreak specially in summer, relatively high morbidity and mortality, productive reduction and economic losses in aquaculture industry. However, it would be necessary to determine of 50% lethal dose (LD50) of bacteria (Streptococcus faecium) and studying its acute effects on hematological and histopathological parameters. For measuring LD50 five dilutions of bacteria were obtained by Macfarlane method and the fish were injected by intraperitoneal (IP). The experience was carried out in 6 treatments and 3 replicates. The fish were injected by LD50 dose and after 10 days, samples of blood and tissues including: Eyes, brain, kidney, liver and gills were collected. The injected fish showed darkening of body, exophthalmia, abdominal distension and prolapsed anal. The obtained results showed significant reduction (P<0.05) in level of red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct) and significant increase (P<0.05) of mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) in test group compare to control group. In addition histopathological findings including hemorrhage in brain, eyes, kidney and liver, congestion in liver, brain and gills, inflammation of gills, meningitis and separation of menangial layers, presence of melanin pigments and increasing of mucus cells in the comial epithelium and were showed shrinkage, bowmans space dilation, degeneration and vacoelation in tubular cells, increasing of melanomacrofage centers and melanin pigments in kidney

    The survey of diversity, distribution and abundance of phytoplankton in the southern part of the Caspian Sea

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    The Study of phytoplankton in the Caspian Sea was substantially started in the 1990s with the aim to produce and record data. phytoplankton study in this area became more important because of the occurance of some ecological events in recent years (such as bloom and arrival invader species). The study was seasonally conducted in western (Giulan province) to eastern coast (Golestan province) at 8 transects (Astra, Anzali, Sefidrud, Tonekabon, Nowshahr, Babolsar, Amirabad and Bandar Turkman) from inshore (5 m depth) to offshore (100 m). 476 samples were collected to study quantification and qualification of phytoplankton in 2009-2010. Results showed that 195 species of phytoplankton were identified in 8 phylums which were classified to Bacillariophyta (81 species), Pyrrophyta (33 species), Cyanophyta (28 species), Chlorophyta (38 species), Euglenophyt (11 species), Xantophyta (1 species), Chrysophyta (2 species) and Haptophyta (1 species). Abundance and biomass of phytoplankton were significantly different between euphotic layer (0 to 20m depths) and aphotic layer (50 to 100m depths) (p0.05). In spring, Bacillariophyta and Pyrrophyta with 40% and 29% of total abundance were dominant phylum at euphotic layer. In fall, Bacillariophyta (57% of total abundance) and Cyanophyta (28% of total abundance) were the first and second dominant phyla. While in summer and winter the predominant phyla was made by Cyanophyta (92% of total abundance) and Bacillariophyta (94% of total abundance) respectively. Species richness in western, central and eastern regions was 119, 141 and 147 respectively. Shannon index was 2.39 and 2.04 at euphotic layer and below photic layer, respectively. Shannon and evenness indices in eastern region was lower than western and central regions. Meanwhile, Shannon index in spring and autmn (2.50 and 2.39) was higher than summer and winter (0.21 and 0.36). In photic layer, dominant species were Stephanodiscus hantzschii Chrysochromulina sp. and Exuviaella cordata in spring. While Oscillatoria sp. was the predominant species in summer. In fall, dominant species contained Thalassionema nitzschioides and Oscillatoria sp. Finally, Pseudonitzschia seriata and Cerataulina pelagica made the most abundance species in winter. The dominant species in the below phoyic layer was very similar to photic layer. The mean abundance of Pseudonitzschia seriata , Oscillatoria sp. and Dactyliosolen fragilissima was higher than other species in all regions of study area (west, middle and east). Seasonal succession of dominant species were under the influence of natural factors such as sunlight, heat, river currents, wind and vertical mixing of water. However it seems that the invasion of ctenophore into Caspian Sea (with change in nutrient levels and decline of phytoplankton predator) and also human activities (i.e. water balance of ships and discharge of sewage) are severely impact on seasonal dominant species, pattern of species composition and relative abundance of species. These changes mainly accompany with appearance of new and harmful species (with the ability of severe proliferation) and displacement of native and dwell species

    Study of physico-chemical Characteristics of water in the southern of Caspian Sea

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    This study was conducted to physico-chemical characteristics of water in the Iranian coastal of southern Caspian Sea during four seasons at 8 transects (Astra, Anzali, Sefidrud, Tonekabon, Nowshahr, Babolsar, Amirabad and Bandar Turkman) during 2009-2010. 480 samples were collected at different layers of water and then analyzed based on standard methods. Results showed that the mean of water temperature were 18.67±0.32 and 17.82±0.43 ◦C at the surface and euphotic layer, respectively. Minimum and maximum of water temperature were recorded in winter (6.40) and summertime (27.60). In addition, temperature gradient was ranged between 12 to 15 ◦C at 20 to 50 layers in 50 and 100m depths. Mean of salinity was 11.04±0.17 g/l at euphotic layer. Pearson correlation between temperature and salinity was positively significant. Therefore, maximum salinity was recorded in summer and minimum in winter. Mean of transparency (SD) in the present study was 4.35±0.21 m which compared to the pervious sampling period (2008) showed small decrease, but the mean of pH was observed 8.43±0.01 which was higher than the previous sampling period (2008). The mean of DO and DO% were observed 5.72±0.06 ml/l and 130±1 percent at euphotic layer during sampling period. The mean of DO% was recorded 104±5 at euphotic layer in 1996 (before introduction of Mnemeiopsis leidyi), but the study in the years 2004, 2008 and present (one decade after introduction of Mnemeiopsis leidyi) this value was registered higher than 120% at euphotic layer. This shows that trophic status of Caspian ecosystem shifted from oligotrophy (before introduction of Mnemeiopsis leidyi) to meso-eutrophy (after introduction of Mnemiopsis leidyi). Annual concentration of inorganic nitrogen (DIN= NH^4 +, NO^2-, NO^3-) has a fairly wide variation. Percentage of nitrogen components out of DIN were varied 9-98, 0.2-28.2 and 0.0-90.0 respectively. In this study, percentage of DIN was lower than 15% and organic nitrogen (DON) was higher than 80%. Overall, results showed that water temperature, salinity, transparency and DON were recorded lower than the previous study (2008), but DO, DO%, pH, NH^4+, NO^3- and DSi were higher than the previous sampling period. Inorganic phosphorous (DIP) and NO^2- have not changed substantially. N/P ratio of Caspian Sea has a narrow range which order of magnificent lower than other seas. The results of the present study showed that Caspian ecosystem was nitrogen limitation before introduction of Mnemiopsis leidyi, while it seems that after introduction of Mnemiopsis leidyi the system has been shifted to the phosphorous limitation

    Study on physico-chemical characteristics of water in the southern of Caspian Sea

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    In this study, the characteristics of physico-chemical parameters of water done in coastal part of the southern Caspian Sea during 2010-2011 (four seasons) in 8 transects (Astara, Anzali, Sefidrour, Tonkabon, Noshahr, Babolsar, Amirabad and Torkman). For measurement of water quality parameters, 480 samples were collected in different water layers by using of APHA standards methods. According to modeling and statistical methods was used multivariate for evaluation of factor analysis (MFA) in general groups and discriminant analysis (MDA) for spatial and temporal with water quality parameters. The statistical procedure of MFA was used for data reduction and finally six factors selected with about 80.48 percent of total variances related to them. The statistical procedures of MDA were used for the role of spatial and temporal of water quality parameters in different water layer. The function one gave eight parameters (pH, salinity, EC, DO, NO^3-, water temperature, NH^4+ and N^-total) affording more than 80, 67, 80, 77 and 71 % correct assignations (return to the same transects) in spatial analysis. In all transects during four seasons, function one gave five parameters (water temperature, salinity, EC, NO^2- and NH^4+) to afford 100, 100, 100, 97 and 97 % correct assignations in temporal analysis. The results showed that, the average amounts in light penetration layers during four seasons were for EC(15.04±0.18ms/cm), pH(8.38±0.01unit), salinity (10.31±0.16g/l), DO(5.67±0.09ml/l) and water temperature (18.28 ±0.72°C). The average amount of nutrients for parameters such as organic and inorganic phosphorus, total phosphorus, NO^2-, NO^3-, NH^4+, N^-Total and SiO_2 were 0.50±0.02, 0.32±0.01, 0.82±0.02, 1.76±0.10, 0.10±0.01, 1.51±0.10, 46.82±1.80 and 8.60±0.29µM, respectively. The average amounts in dark layers during four seasons were for EC (15.46±0.38ms/cm), pH (8.34±0.03unit), salinity (10.70±0.35g/l), DO (4.55±0.13ml/l) and water temperature (9.62 ±0.16°C). The average amount of nutrients for parameters such as organic and inorganic phosphorus, total phosphorus, NO^2-, NO^3-, NH^4+, N^-Total and SiO_2 were 0.54 ±0.05, 0.33 ±0.02, 0.87±0.06, 1.92±0.21 , 0.08± 0.01, 1.55±0.25, 45.10±3.25 and 10.05±0.62 µM, respectively. The average amounts of light penetration in all transects during four seasons 4.49±0.38 meters. The maximum light penetrations during spring, summer, fall and winter seasons were 9, 8, 8.20 and 7 meters, respectively. The maximum water temperatures in light and dark layers were 32.36 and 11.50°C. Also, the maximum differences about thermocline temperature during summer and fall seasons were 19.6°C and 10°C, respectively in southern part of Caspian Sea. Data in spatial analysis were not significant (p>0.05), it means if add or removed any transect did not change occurred. But in temporal analysis were significant (p<0.01), and it means no way remove any seasons for a research work on Caspian Sea in southern part. In those transects with 100m depth. Water temperature is only highly effective parameter between other parameters. In function 1 between 3 functions in transects with 100m depth water temperature with 60% variance was the main role and effective between different seasons in depth part were very high

    Production of bacterial probiotic from trout (Oncorhynchus mykiss) for improvement of immune system and challenge to streptococcosis

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    This study was conducted for the first time and the effects of probiotic bacteria isolated from the gut of Rainbow trout (Oncorhynchus mykiss). In the first step, after the purification of the isolated bacteria, probiotic properties in vitro was assessed with injection to healthy fish and challenge with three species of pathogenic bacteria in culture media. The second phase of the bacteria isolated in 5 treatments (log 7, 8 and 9 of the lactic bacteria (LAB), Vibrio sp and Pseudomonas sp) and a control treatment on growth and survival, hematological parameters (RBC and WBC cells), immunology and physiology parameters tested during the 60 days of the above parameters after 30 and 60 days and finally at the end, the final assessment was Streptococcosis resistance in fish. The results showed that the isolated bacteria were able to enhance the growth parameters (weight, feed conversion, feed fat, protein efficiency ratio and specific growth rate) and survival. The results showed that log 8 LAB was significant difference with other treatments and control. When using log 8 LAB and Vibrio, the MCV, MCH and MCHC were decreased with no significant difference. The log 8 has the greatest effect on the amount of liver enzyme (AST), IgM and complement component C3, and had significant difference with other treatments. The challenge examination to Streptococcus iniae showed the highest survival in treatments with log 8 (96.66%), and Vibrio (93.33%) and then subjected to other treatments and control are also the least survival (25.38%). The conclusion of that study is the first probiotic properties of bacteria isolated from trout to changes in quality indicators are in particular the LAB bacteria and the second log 8 of LAB had significant positive of changes development and safety, and the fish are resistanted against Streptococcosis

    The study abundance, distribution and diversity of zooplankton in the southern of Caspian Sea

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    This survey was carried out by R/V Guilan ship with a conical plankton net of 100 micron mesh by vertical hauls at different stations and depths of 5, 10, 20, 50 and 100m in 4 seasons of 2010. In this study, 16 species formed the zooplankton community including 4 species of Copepoda, 4 species of Rotatoria, 2 species of Protozoa and 4 species of Cladocera from Holoplanktons and 2 species of Balanus sp and Lamellibranchiata larvae from Meroplanktons. The annual results revealed that the mean abundance of zooplankton were 5477±5815 ind/m^3 and 5131±7908 ind/m^3 in spring and winter respectively which were more than other seasons but the maximum biomass (64/58±124/61mg/m^3 ) was in winter that was affected by Rotatoria. The maximum mean abundance and biomass of Copepoda were in summer that were 2830±2342 ind/m^3 and 22/52±21/78 mg/m^3 ,respectively and the abundance decreased gradually since autumn and reached the least in winter but increased since spring. The mean maximum abundance of Cladocera (115 ±142 ind/m^3) was in spring but it decreased gradually, so it reached to less than 3 ind/m^3 in summer. The Protozoa constituted the least community and biomass of zooplankton in southern area of Caspian Sea. The zooplankton community also was affected by Meroplanktons including Cirripedia and Lamellibranchiata Larvae in spring and the Rotatoria contributed highly in zooplankton community in winter with the mean abundance and biomass of 2604±5876 ind/m^3 and 50/71±115/33 mg/m^3 respectively.Other than Copepoda, other planktonic groups contributed lowly in zooplankton community. It was observed the reduction trend in abundance from surface depths to deeper depths in whole of the year. There were 75% of zooplankton community in stations with 5 to 20m depth and 25% of community in stations with 50 to 100m depth in spring, and also 74% in stations with 5 to 20m depth and 26% in stations with 50 to 100m depth in summer, 73% in stations with 5 to 20m depth and 27% in stations with 50 to 100m depth in autumn and 85% in stations with 5 to 20m depth and 15% in stations with 50 to 100m depth in winter. In analysis of different area of southern basin of Caspian sea the maximum abundance was observed in west in spring, summer and winter which were 7514±8115 ind/m^3, 3909±2609 ind/m^3 and 8129±11587 ind/m^3, respectively. There was 2283±2134 ind/m^3 in center area in autumn. The annual statistical analysis revealed that, there was significant difference in total zooplankton community between sampling stations, depths and layers in whole of the year

    Creation of cryopreservation bank of bony fish

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    In this study, 11 male of Caspian trout (Salmo truta caspius) (with mean length and weight 37/8 ± 5/3 cm and 523/3 ± 24/7 respectively) and 23 male of Caspian kutum (Rutilus frisii kutum) (with mean length and weight 36/1 ± 7/1 cm and 631/3 ± 21/6 g respectively) were evaluated. All the fish were good at the initial examination of sexual maturity. After sperm sampling, their quality were tested. In this step, the parameters such as motility, duration of mobility, density, pH and osmolality were measured. After this stage, the sperm samples of Caspian trout in the ratio 1: 3 were diluted with the aqueous solution containing compounds (0.3M Glucose, 10% Methanol, 10% egg yolk) and the freezing process was done manually and the sperm was frozen in liquid nitrogen. The sperm samples of Caspian kutums were diluted (ratio of 1: 3) with two soluble diluent containing compounds (350 mM glucose, 30 mM Tris and 4% Polyethylene glycol) and (350 mM glucose, 30 mM Tris and 2% Glycerol) and were frizzed automatically by Planner Kryo instrument and placed in liquid nitrogen. The sperm samples were thawed 1 to 3 months after the date of first freezing and their quality were assessed by measuring percent and timing motility. The results showed that the obtained semen volume of Caspian trout was more than Caspian kutum. Moreover, percentage of motile sperm, timing motility and sperm density of Caspian trout were higher than those of Caspian kutum but osmolality and pH of Caspian trout were lower than those of Caspian kutum. Over time, the percentage of sperm motility and mobility for both species declined compared with fresh samples. After thawing, percentage of motile sperm and timing motility of Caspian kutum were lower than those factors Caspian trout. The results showed that the sample of Caspian kutum sperm that were diluted by ethylene glycol after thawing and were immotile ll of them. However, the samples were diluted by glycerol, after thawing, were alive and motile. According to the results, it seems very important species differences that must be fully considered in the process of freezing sperm. The use of a single protocol would not be successful in cryopreservation because the reaction of sperm against to chemical agents is variable. Therefore, it is essential to get the right information to protect valuable Caspian fish by using cryopreservation. Further studies on the characteristics of each species, as well as the freezing process take appropriate diluent

    Study on physic-chemical parameters of waters for fish cage culture site selection in the southern of Caspian Sea

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    Marine aquacultures growth require good quality water is leading to high efficiency and low risk to human health. In other words, the water quality is a critical factor to success and failure of the aquaculture industry. The aim of this project is to study water quality and the trophic status at the different depths and layers in the southern Caspian Sea based on environmental parameters and nutrients during three periods (2008, 2009 and 2010-2011) in order the feasibility of fish cage. Results showed that water temperature, transparency, pH, dissolved oxygen were varied 5.50-32.60 ̊C, 3.50- 10.00 m, 7.15-8.80 and 3.18-12.00 mg/l at the different depths and layers, respectively. In addition, The values of NH4^+, NH3, NO^2-, NO3^- and PO4^-3 were 0.001-0.140 mg/l, 0.01-22.63 µg/l, 0.1-21.2 µg/l, 0.001-0.423 mg/l and 0.008-0.071 mg/l, respectively. Inorganic nitrogen (DIN/N), inorganic phosphorous (DIP/P) and total phosphorous (TP) were registerd 0.68-14.75, 0.07-0.68 and 0.01-2.67 µM, respectively. Thermal startification are more important for fish-breeding. Thermal stratification was occurred from depths greater than 20 m in late spring to early fall in the Caspian Sea. Optimum transparency for fish farming cage was considered less than 5 meter which in this study were recorded from 20 to 50 meter depths. The range of the standard of pH and dissolved oxygen for fish farming cage were 7.80-8.50 and >5 mg /l that in current study results of pH and dissolved oxygen were consistent.Various forms of nitrogen (ammonium, nitrite and nitrate ) at the different layers were acceptable and less than the threshold limit of Australia and New Zealand. But, phosphate value was more than threshold limit of Australia and New Zealand at some layers depth during years of 2009 and 2010- 2011. The results of the nutrients compared with data from the reference year (1996-1996 ) in the Caspian Sea was shown that this ecosystem passed oligotrophic status and shifted to mezotrophic and eutrophic condition. In addition, the values of NH4/N, NO3/N and DIP/P compared with eutrophic condition of reference year (2005) showed that Caspian ecosystem was not passed euotrophic condition and it still under mezotrophic status. As a conclusion, it seems that offshore of the Caspian Sea (depths between 20 to 50 meter) were suitable for different species of fish for cage culture. But, since 2000 decayds the Caspian Sea has experienced four times algal bloom (toxic and harmful species) and in recent years a number of other species also has reached to bloom potential and also mezotrophic condition of this ecosystem, it is appropriate that the establishment of fish farming cages carried out as a pilot to more precautionary approach which not lead to environmental disaster

    Survey of diversity, distribution, abundance and biomass of macrobenthic fauna in the southern Caspian Sea

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    The Sampling of macrobenthic communities in southeastern Caspian Sea, Iranian coast, were investigated seasonally from April to March 2012. Sampling was carried out at 8 transect as named Astara, Badar Anzali, Sefied rood, Tonekaboon, Nooshahr, Babolsar, Amirabad, Gomishan.In each transect were choice 8 stations at 5m, 10m, 20m, 50m, 100m depths respectively. Samples were taken in triplet with a 0.1m^² van Veen grab.Totally 28 macrofaunal species belonging to 10 families were identified as gamaridae (9species), corophidae (3species),psudocumidae(8 species), amphartidae (2species), balanidae, chironomidae, cardidae scorbicolaridae, nereidae, sponoidae, each one species. Polychaetes were dominated, representing 72.5% of the whole fauna while while (equal 62.4% of total abundance and 5/1%biomass) were belong to Streblospio spp. from Spionidae family. Cerastoderma lamarcki belong to bivavia consist of 2/3% total macobethos abundance and 73% biomass. Total abundance of macrobenthos of middle area were higher than east and west area in southern Caspian Sea. Average benthic population density (no/m^2) with (SE) was 4581(444 ). The benthic biomass (mg/m^2) with an overall mean of 12. 125(02). Spatial and temporal variations of benthos. In the present study showed, maximum abundance Macrobenthos 17855(5543) no/m^2) were recorded in 20 meter depths at Nooshahr trancect , while minimum 841(109 )in 10 meter depths at Amirabad trancect p<0.05. Maximum biomass 135.10(126) g/m^2 were obtained at 10m depths in Astara minimum 0.51(0.4) ) g/m^2 at 5m depths in Nooshahr transect . maximum were obtained in winter and minimum in summer Number of species varied 3 to 18 , Generally, minimum species diversity were obtained at 20 m depth in Tonekabon transects and the maximum value was observed at 100 m depth of sefeidrood variations physicochemical factors were between salinity 12.5to12.9ppt ,temperature 8-19˚c and PH 8.1 dissolve oxygen 69-101mg/li. Total secondary production calculated, according ,104/996g AFDW/m^2/yr.Maximum were recorded in 10meter depth (30/381AFDW/m^2/yr) and minimum at 50 meter depth(11/007g AFDW/m^2/yr) respectively. Average total organic matter were 3/18 percent in sample periods. Percent of total organic matter (TOM) were low in 5 and 10 m depths and increased toward offshore depths. TOM percent was 1/67(0.11 ) at 5 m depth and increased to 4/38(0.13 )in 100 m depth. Average total silt &clay were 68/63(2.97) percent in sample periods. Positive significant relation was between silt &clay and total organic matter. Macrobenthos community reduce in high silt clay and high sandy contents. Due to increase of streptolosbio.spp, monitoring program for understanding effect of this organism on ecosystem and on fish feeding is necessary
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