NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2013 | Volume:6 | Issue:4 (24)|Papers Count:12

In this study, the effect of 17-b estradiol on hematological indices in juvenile stellate sturgeon (AciPenser stellatus) was investigated. For this, 180 five-month juvenile stellate sturgeons with an average weight of 11.7 ± 0.2 g were divided to 3 treatments (20 fish/tank). The treatments were included 0, 25 and 50 mg E2/kg diet. The duration of the exPeriment was considered for 7 months and fish were fed according to their satiation. At the end of the exPeriment, 5 fish were randomly samPled for measuring hematological indices including number of red (RBC) and white blood cells (WBC), hemoglobin (Hb), hematocrit (Hct) and differential leukocyte count. Results showed that significant decrease of WBC, RBC, Hb and HCT with increasing of hormone dosage (P<0.05), but there were no significant differences between control and fish fed 25 mg/kg in those Parameters (P>0.05). Also, no significant different (P>0.05) were found among the treatments in other hematological indices including MCV, MCH, MCHC and differential leukocyte counts (neutroPhil, lymPhocyte, monocyte and eosinoPhil). The results of this study demonstrated that E2 could cause an anemia in fish which fed by dietary E2 and the intensity of anemia is directly dePended on hormonal dosage, but it seems that the diversity of leukocyte was not affected by hormonal treatment.

In order to study the biochemical characteristics of Iranian and French rainbow trouts broodstocks, 60 fish from two culture fish station of Amol, were catched in winter 2011. Serum samples of Acipenser persicus were analysed and their total protein and Alobomin were determined by the methods of Biore and Brom kerzol-carbone, respectively. The Igm, C3, C4 analysis were determined by imuno-turbidity assay. In most of the parameters such as Igm between French sample (94±26.5 mg/dl) compare Iranian rainbow trout (82.5±44.8 mg/dl) the difference was pronounced but not significant (P>0.05). There were no significant differences in case of the C3 (33±14.7 mg/dl; French sample) and (31±4.2 mg/dl Iran sample) as well as C4 (12±5.9 mg/dl; French sample) and (13.9±4.5 mg/dl; Iran sample). Total protein in French and Iranian groups were 6.3±4.4 and 4.7±2.1, respectively and this parameter was the only factor showed significant differences between two groups (P<0.05).

In this study, the compatibility conditions and growth of rainbow trout in the earthen ponds (with brackish water of the Caspian Sea), that unused in the cold seasons of year were examined. For this propose, 15,600 pieces of juvenile of rainbow trout with average weight of 32 grams introduce in a 1 hectare earth pond. The duration of rearing period was 105 days. The average salinity of water was 16 ppt. At the end of period, average weight of fish was 270 g, the survival rate was 71% and the feed conversion ratio was 1.27. Rearing of rainbow trout in cold seasons of the year in earthen ponds of Gomishan center and production more than 3 tons of fish/1hectar showed that we enable the optimal use of facilities for production of shrimp and fish through the year with Caspian Sea brackish water. In this way, we can have new jobs , produce protein and developing the area.

In this study, the effect of using fish and vegetable oils (Corn and Sunflower) in terms of biochemical and fatty acids profile of corpse of Persian sturgeon larvae during 8 weeks was compared. Three different treatments including 100% corn oil, 100% sunflower oil and 100% fish oil, each of them were examined. Nutritive ration formula was examined contained of 2% oil based on different treatments. Biochemical composition profile of Acipenser persicus larvae consisting of raw protein, raw fat, moisture and ash among different treatments studied. Lowest and highest protein range, obtained in second treatment respectively (15.2% and 16.4%). Lowest and highest fat range of profile obtained in third and second treatment respectively (3.8% and 5.2%). Highest Linolenic acid, content, obtained in the first treatment and in third treatment was the lowest one. Highest level of Linoleic acid obtained in second treatment and lowest level of Linoleic acid observed in the first treatment. Highest level of Arashidonic acid obtained in the second treatment and lowest level of Arashidonic acid obtained in the third treatment. Highest level of SFA obtained in the third treatment and lowest level of SFA obtained in the first treatment. Highest level of (n-3) PUFA obtained in the first treatment while highest level of (n-6) PUFA obtained in the second treatment. Highest level of EPA, DHA obtained in the third treatment in contrast lowest level of EPA, DHA obtained in the second treatment. The ratio of DHA/EPA was the lowest on corn oil and the highest on fish oil. The results showed that considering Persian sturgeon larvae absorb more protein from nutrition contained fish oil it can be more appropriate and healthy for fish. But according high amount of Linolenic acid at treatment 2 and high Linolenic acid at treatment 1 and also other fatty acids in series of n-3PUFA, n-6PUFA, vegetable oils specially sunflower oil can be use temporarily in this age group of Persian sturgeon.

The main objective of the present study was qualitative assessment of three species of kilka (anchovy kilka: Clupeonella engrauliformis Svetovidov, 1941; bigeye kilka: C. grimmi Kessler, 18771 and common kilka: C. cultriventris Bordin, 1904) stocks by using indicators of overfishing in Iranian waters of the Caspian Sea during a long period (1996-2011). Three fisheries indicators in catch were: 1. percentage of mature fish, with 100% as target; 2. percent of specimens with optimum length, with 100% as target; and 3. percentage of mega-spawners, with 0% as target. According to the results, the ranges of length with optimum yield for three species of kilka were 85-105, 90-110 and 80-100 mm, and the mega-spawner measured as fish a size larger than 100, 110 and 105 mm, respectively. During the period, for three species of kilka, the percentage of mature had an increasing trend. The optimum size declined since 2004 for anchovy, 2002 for bigeye and 2005 for common kilka. The percentage of mature of anchovy and bigeye kilka were more than 78% (often more than 95%). For common kilka, it decreased from 100% to 58% in 1999 and the increased to 90% in 2001. The mega-spawners of three species had and inverse trend. The length structures of anchovy and bigeye kilka are a matter of concern. According to the present study, the stock of common kilka had a better situation than anchovy and bigeye kilka in the Caspian Sea. 

The dumping of solid waste in uncontrolled landfills can cause significant impacts on the environment and human health. The principal concern is focused on the pollution potential due to migration of the leachate generated from the landfill sites into the groundwater, the surface water or the sea. In this study, used of a technique that has been developed to quantify the landfill leachate pollution using an index known as Leachate Pollution Index (LPI). Also, monitoring of leachate quality was carried out at three dump sites as Talesh, Roudsar, and Ferydounkenar from cities of northern Iran. The leachates were monitored for changes in pH, TDS, COD, BOD, TKN, Ammonia-Nitrogen, and heavy metals. Leachate Pollution Index (LPI) for Talesh, Roudsar, and Frydunkenar leachate was 23.64, 27.51, and 17.96, respectively. These results showed that Roudsar leachate is more polluted than Talesh, and Frydunkenar leachate. Further, leachates of three dump sites showed that higher LPI value those than of 7.4 obtained for the treated leachate that can be disposed into inland surface water  are more.

Evaluation of pathological effects resulting from levels lower than the lethal concentration of Roundup on gonad tissue and gonad index of male breeders rainbow trout of south of the Caspian Sea was conducted during the fall of 2011.Number of 120 fish with a average weight of 185 grams were exposed to 25%, 50%, and 75% of concentration of LC50 of Roundup. Three treatments including 5, 10, and 15 ppm with a control group were established. Testing period, were considered in two periods of 5 and 10 days. Gonad tissue were sampled at the end of each period. Studies on the effects of estrogen-like compounds showed that these compounds affect fish gonad tissue. The results showed that Roundup affects the maturation of sexual cells in both trials but no significant difference was observed between them. In 75% of concentration of LC50, demolition and removal of large number of spermatogonia from spermatogenesis cycle finally led to reduced production of spermatozoa. In 25% and 50% of concentration of LC50, arrangement of  lobules was irregular and less and more dispersed spermatogonia was observed in content of tubes. Primary spermatocytes (SPI) and secondary spermatocytes (SPII) were observed in form of cluster. In fact, there was no significant difference between 25% and 50% of concentration of LC50. The results also showed that gonad index decreased in both trials from low to high concentrations compared with the control.

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.

In order to investigation of propagation and cultivation capability of Metapenaeus affinis in Sistan and Balouchestan province,. 4 broodstocks were catched from Pazm gulf, and then propagated in Meygo Kesht Center which is located in Kenarak. In total, 952750 larvae with efficiency of 238188 ind. per each broodstock were produced; furthermore, as the numbers of collected eggs were 1341901, the survivability of egg stage to 15 day larvae was 71 percent. After that, cultivation capability of this species was studied for the first time by transferring the larvae to three cultivated ponds with the space of 1.1 ha. The number of larvae stocked in each pond was 319000,227000 and 319000, respectively. After the cultivation period, amount of 2126, 2204 and 2212 kg M. affinis were produced after 129, 130 and 131 days, respectively. These amounts of products are record for this species in Iran, that it shows many capabilities for continuing more investigative programs.

In this study the different sex ratio of male and female in the reproduction of Poecilia reticulat were lasted for 5 months (from August to January) in five treatments including; A,B,C,D and E with the ratio of female to male in the order of 1:1 (F:M), 2:1 (F:M), 3:1 (F:M), 1:2 (F:M), 1:3 (F:M) was achieved. The fecundity, the period of pregnancy and the percentage of the survival of the fries were obtained after 40 days. The treatment C which is generally applied in reproduction workshops was considered as control. During the investigation, the temperature, dissolved oxygen, pH, hardness, nutrition and other factors were kept the same for all of the treatments. Generally, the increase of the number of female broodstocks in comparison with males, the number of fries and the survival percentage decreased and with the increase of the male broodstocks compared with famales, the number of fries and the period of pregnancy decreased. The results indicated that the A treatment with the sex ratio of one male and one female with the highest fecundity and survival of the fries was the best sex ratio in the production of Poecilia reticulate.

A 60-day feeding trail was conducted to examine the effect of dietary Ergosan on growth performance and survival rate in rainbow trout (Oncorhynchus mykiss). Ergosan supplemented at 0, 3, 5 and 7 g kg-1 diet. Each diet was fed to groups of rainbow trout with initial body weight of 1 g at 10 days intervals. Control group fed non-supplemented diet at total period of experiment. Daily feed intake (DFI), daily weight gain (DWG), feed conversion ratio (FCR), protein efficiency ratio (PER) and specific growth rate (SGR) in the fish fed supplemented diets were higher and better than the control group, but differences between them were not statistically significant (P>0.05). Survival rate in the fish fed supplemented diets was statistically higher than the control group (P<0.05). These results indicated that supplemented diet with 5 g kg-1 had the best effect and dietary administration of Ergosan affected on some growth parameters and survival rate in rainbow trout.