Journal of Aquaculture Development
Year:2013 | Volume:6 | Issue:2|Papers Count:8

The present study was conducted with the objective to compare growth rates in Acipenser persicus (Persian sturgeon) and Acipenser ruthenus (Sterlet sturgeon) in aquaria at the International Sturgeon Research Institute for the first time in Iran. A total of 30 A. persicus and A. ruthenus with the initial weight of 26.6 ± 4.9 g (mean ±SD) and 29 ± 3.7 g (mean ±SD), respectively were randomly distributed in six 120 L aquaria. The sturgeons were fed a formulated diet, with 48 % protein, 18 % lipid and 20 % carbohydrate, with less than 10 % moisture. Depending on temperature, feeding rate was changed from 1 to 1.5 % of body weights. Fish were fed twice a day. To determine the fish growth rates in aquaria, data were analyzed by one-way analysis of variance. The analysis of variance revealed that there were no significant differences in FCR, Final weight, SGR, Gr and BWI % among treatments after 270 days of rearing (P<0.05). At the end of the experiment, Persian Sturgeon reached an average weight of 182 ± 28 g and Sterlet sturgeon reached an average weight of 180.7  ± 34 g. Results obtained from total length were as the same as weight results. Also based on the feeding indices (FCR, SGR, BWI and GR) in this study, rearing of Persian and Serlet sturgeons in aquaria was more acceptable. However, there were no significant effects among growth and feeding parameters. Although the feeding of these two sturgeon species is related to dry formulated diets, results obtained from this study revealed that Persian and Sterlet sturgeons can grow up to 612% and 533% of their initial weights. No mortality was observed in experimental treatments during the rearing period.

In this study, lead concentrations (Pb) was analyzed in the muscle, liver and gills of carp (Cyprinus carpio), sediment and water ponds in three sites of the Karun river directions included: north (Shushtar), center (Ahwaz) and south (Khorramshahr) in autumn 2010. In each site, three farms were selected and five fishes in the marketing size for each farm (totally 45 fishes), were caught and measured. Also, three couple samples (sediment and water) were taken from each site. Some bioassay characteristics were determined. Also, the Pb concentrations of muscle, liver and gill (wetting ash method), sediment and water were measured by using ICP (ULTIMA C- HORIBA JOBIN YVON model France Made). The results showed that there was no significant for bioassay characteristics of common carp on different sites. The highest and lowest Pb concentrations were 3.03 (Ahvaz region) and 1.13 (Khorramshahr region) mg Pb .kg-1 dry weight on muscles respectively. The mean Pb concentrations of different tissues were obtained 2.01, 1.9 and 1.73 (mg .kg-1 dry weight) in muscles>liver>gill respectively. The results revealed that Pb bioaccumulation on edible tissue (muscle) more than Codex Alimentarius Commission level 0.2 mg kg-1 dry weight) (2002) on study sites. The mean of Pb concentration of sediment (13.03 mg kg-1) and water (5.76 mg l-1) were no significance difference on different regions (p ³0.05). The results showed that an increased load of sediment contamination in the northern to southern of the study area. However, the lowest and the highest of Pb sediment concentrations were obtained 11.98 and 13.71 (mg kg-1) on Shushtar and Khoramshar sites respectively.

This study was conducted to investigate the influence of repeated acute stresses on the physiological status and non-specific immune responses of goldfish, Carassius auratus. The acute stress was comprised of 3 min chasing and then 2 min air exposure stresses. The goldfish were subjected to 3 times stress in a day (S3), moreover, a group of unstressed fish was used as control for each sampling time. The blood samples of both stressed and unstressed fish were collected at 12, 48 and 120 h after last stress procedure in order to assess physiological and immunological responses. Plasma cortisol and glucose levels in stressed fish were significantly higher than that of control until 48 h post-stresses. The hematological parameters and plasma total protein, albumin and globulin were not significant differences between sampling times or treatment. In addition, plasma antiproteases activity did not significantly vary between treatments and sampling times. This study has revealed that prolonged acute stress could result in prolonged stress responses in goldfish and this species is not able to be adapted with acute stress.

A ccording to decrease sturgeon stocks in Caspian sea and more using needfulness of sexual matter, sperm male brood stokes that are immotile in the testis and are activated after releasing into aquatic medium. This activitation are affected the environmental of factors such as salinity, ion concentration, pH, etc., that prerequisite sperm motility. In this experiment that was conducted in Shahid Beheshti sturgeon rearing and reproduction center and Dr. Dadman international sturgeon research institute During March-April 2009,sexual matter from 4 male brood stock were studied in 5 different salinity treatment 0‰, 0.6‰ (control group), 2‰, 4‰ and 6.‰ Na+, ca2+and K+ ions were measured in useable solution and seminal fluid of sperm from brood stock. Sperm motility percentage and duration of sperm motility was resulted in salinity 2‰ in comparison with other treatment and was shown significant statistical differences between percentage motility sperm in different salinity treatment.

Caspian trout is valuable, Commercial, anadromous and endemic fish species in the Caspian Sea so that, researchers attention have been focused on this species. At the moment, only pay attention to stocks rehabilitation that fisheries organization releases more than 300,000 fingerlings to the rivers ends to the Caspian Sea. Importance of this study consist (1) introducing a new species to the aquaculture system and (2) provide breeders in this research. we used from 2 treatments that consist with density of 10 kg/m3 and 20 kg/m3 with 3 replication. Results showed, Mean weight gain in treatments with 10 and 20 kg/m3 reached to 1953.9 and 1734% that there were significant differences (ρ<0.05) in comparison with initial weight (10.1 gr). Special growth rate in 1 and 2 treatments were calculated 1.37 and 1.32% in day respectively that there were significant differences. Initial and end condition factor (CF) were 1.07 and 1.12 respectively. Fishes survival rate in 1 and 2 treatments determined 92 and 88 % respectively. Results showed, culture of Caspian trout is suitable with density 10 kg/m3, so that weight gain, SGR and Daily growth mean are better than treatment 2 (15-20 kg/m3).

A carbon source for the growth of micro-algae is essential, therefore, to increase the yield production, carbon supply is one of the most important steps in the development of micro-algae. In this study, the effect of sodium bicarbonate (NaHCO3) concentrations on Chlorella (Chlorophyta) growth was evaluated in TMRL (AG) medium. In this purpose, we studied the effects of the different sodium bicarbonate concentrations (2.5, 5, 7.5, and 10 ml). The fluctuation of Chlorella growth in TMRL medium changed with different concentrations of sodium bicarbonate during 10 days in the laboratory. The counting of samples was carried out in each 2 days, as a total of, five times counting. The obtained results were shown that T3 has been much growth with 7.5 ml in term of the number of cell (119×106 cell.ml), when the different concentrations of sodium bicarbonate were added to TMRL medium. In T3 medium, Chlorella showed rapid grow as the growth rate and coefficient were calculated which are 2.30 and 0.15, respectively. According to the results, the use of sodium bicarbonate in normal and cheap TMRL (AG) medium modified for mass production of micro algae Chlorella is recommended.

With the right understanding of the status of some blood indices can be improved conservation, restoration and development of this valuable fish. In this study was done to survey the effects of salinity on some of blood serum indices of Persian sturgeon juveniles (Acipenser persicus). 400 of Persian sturgeon juveniles with weight average 2.43 to 7.38 grams was selected and distributed into eight tanks (100-liter ) with different salinity levels (5, 7, 10 and 15 ppt) at Gharreso Research Station when they have been releasing to the Caspian Sea (50 fishes per tank). Blood sampling was performed to cut the caudal peduncle at 0, 2, 6, 12, 24 hours and blood samples were transferred to the laboratory for biochemical measurement parameters (blood serum cortisol, glucose, sodium and potassium). Cortisol was measured by radioimmunoassay, blood glucose by enzymatic methods and sodium and potassium ions by flame photometer. Results of biochemical parameters showed no significant difference with 5 and 7 ppt salinity levels among the hours. Based on Dennett T3 test, there are significant differences in blood glucose and potassium with 10 and 15 ppt salinity levels and blood sodium with 15 ppt among the hours. Blood glucose levels decreased initially and then increased with increasing salinity, and levels of blood sodium increased and levels of blood potassium decreased. In according to Tukey test, blood serum sodium and potassium showed significant differences among different salinity levels and the different hours. Results indicate the blood biochemical parameters affected by salinity and blood ion concentration and they depend on the salinity and ion concentration in environment.

The purpose of this study impact of untreated wastewater farms on Benthic macro invertebrates in Zaringol stream is because the waste water entering the streams and rivers on the structure and composition of affected streams and cause imbalance to ecosystems .so in this study was selected two trout farms and in the distance about 22 km, 9 stations to determine and study every 45 days once the Benthic invertebrates were sampled. Sampled during one year of the study area 14 orders, 81 groups( families and genus) were identified and the total abundance at all stations 2749.021 ± 1301.8 samples per square meter were counted. The results showed that aquaculture significant effect on the richness EPT, richness EPT / CHIR(p<0/05), but a significant difference between the Shannon index and Hilsenhoff index in stations upstream and downstream fish farms has not been observed(p>0/05). So in the station after the aquaculture richness EPT, richness EPT / CHIR and Shannon index were reduction. Review the indicators showed that in the stations After aquaculture ,diversity of invertebrates and many families sensitive to pollution reduction and Families resistance to infection indicates has increased that water quality is reduced.