فصلنامه آبزیان و شیلات
پیاپی 8 (زمستان 1390)

In this research, purgatory effects of Tetraselmis suecica microalgae were studied. The purpose of this study was the evaluation of this microalgae's capability at different concentrations in order to remove ammonia and phosphorus from wastewater. For this purpose T. suecica microalgae was cultured under controlled laboratory conditions at three initial densities(5×105, 1×106, 2×106 as low, moderate and high, respectively) in 250 cc of wastewater for 14 days. During the period of culturing, the concentration of phosphate, nitrite and nitrate was determined by standard method of measuring by using ultraviolet spectrophotometer. Low and moderate concentrations of this microalga showed the removal rate of 80%, 71.6% and 56.3% for nitrate, phosphate and nitrite respectively. These results show the capability of T. suecica for N and P removing from wastewater as well as the possibility of its use in order to purification of wastewater, so that higher densities show more satisfactory results in N and P removing.

Vitamins are complex organic compounds that have vital importance for fish and their deficiency causes severe abnormalities in body. 9 diets were supplemented with a combination of 0, 100 and 400 mg/kg food vitamin C and 0, 100 and 400 mg/kg food vitamin E were fed to sterlets in 2 replicates for 15 weeks. A total of 270 sterlets with the average weight of 350.92 ± 14.28 g were introduced to 18 fiberglass tanks. At the end of experiment, stress test (including exposure to air, water volume reduction and oxygen deficit) was performed and blood samples were randomly collected from 3 fish per tank. The results showed that after stress test, the minimum and the maximum content of cortisol were recorded in treatments (9) E400 C400 mg/kg (25.69±0.31ng/ml) and (4) E100 C0 (54.22±0.44 ng/ml) (interactions of vitamins), respectively which had significant difference (P<0.05). After stress test the minimum and the maximum content of glucose were recorded in treatments (9) E400 C400 mg/kg (68.49±0.16 mg/dl) and (2) E0 C100 (98.27±0.38 mg/dl), respectively which had significant difference (P<0.05). Based on the obtained results, it can be declared that high levels of vitamins C and E and interaction of them can have positive effects on reduction of bad effects of stress in sterlets.

The analysis of blood parameters is a useful indicator in assessing the physiological conditions of aquatic animals in response to stress, pollutants, nutrition, and also physiological and ecological changes. In this study differential leucocyte count of Huso huso in three age classes including frys, juveniles and brood stocks were studied in International Sturgeon Research Institute in a six-month period (spring and summer) in 2012. For this reason, 30 Huso huso (10 frys, 10 juveniles, 5 males and 5 females) were used. Statistical results showed significant differences in WBC, lymphocyte (%), neutrophil (%) monocyte (%) and eosinophil (%) in different ages (P<0.05). There was no significant difference between brood stocks (P>0.05) and percent of lymphocyte and neutrophil was higher than in males whereas in females percent of eosinophil and monocyte was higher. Based on the results, it can be declared that parameters such as age and sex can be more effective on hematological indices.

This study investigated Macrobenthos density of western white shrimp farms in the Golestan province, Gomishan region. Two saltwater ponds with levels 1 ha and the average depth of 1.5 m was used. In the Gomishan Center and Promote Aquaculture, sampling of sediments from five stations (output, intermediate inputs and sides) was done by using Grab with 262 cm2 surface area during the growing period (from July to October 1389). The samples were stained with Rose Bengal (1 gr/lit) solution later was fixed with 70% ethyl alcohol. Then it was passed through a 500 micron sieve, and the Macrobenthos were remained, which was inspected and counted. Every ten days the temperature, pH and salinity were measured. Macrofauna organisms identified that were related to the category selected in this study were Gastropoda, Bivalvia, polychaete, Insecta, Crustacea. The highest abundances of the ponds 6 and 16 (67% and 58% respectively) are related to Polychaete. Moreover the lowest abundances (2% and 5% respectively) are related to Crustacea. Furthermore, the lowest abundance of Macrobenthos in mentioned ponds belonged to right sides. The highest abundances in ponds of 6 and 16 belonged to input and left sides. The results of T test of the total Macrobenthos abundance comparison between ponds 6 and 16 were insignificant (p>0.05). Macrobenthoses abundance compared in different months (June to September) showed relative decreased, however this difference was significant (p<0.05). Compared factors (temperature, pH and salinity) had not significant differences between the two ponds (p>0.05), however there was significant differences between different months, morning and afternoon (p<0.05).

This research carried out to study of using of edible film to cleaned Kilka packaging and its quality assessment. Treats are coated Kilka fish by mixing of whey protein and sodium alginate (12% and 0.5% concentration, respectively) at times 2 and 4 hour in this research. The samples were kept at -18 oC for a period of six months. Coated and control Kilka(Kilka without edible film) studied for Nutritional value, bacterial, chemical and sensory factors per monthly from the first day, first month until the end of sixth storage. According to results, total bacterial counts of mesophilic and termophilic aerobic bacteria and Staphylococcus bacteria count were most lower in the covered samples at time 4 hour compared with the covered samples at time 2 hour. Coliform, Escherichia coli and Pseudomonas bacterial contamination were not observed in the samples. In Nutritional value there were not significant difference in among control and coated samples(P>0.05). In this factor there was not significant difference between the covered samples at time 4 hour compared with the covered samples at time 2 hour too(P>0.05). Peroxide value, free fatty acids, thiobarbitoric acid, TVN and pH changes were most higher in the covered samples at 2 hour samples compared with the covered samples at 4 hour samples. But, these factors were lower increasing in these treats compared with the control samples. Sensory analysis carried out to Ranking method. In chemical and bacterial factors and overall acceptable score there were significant difference between the covered samples and control ones (P<0.05). The covered samples had a favorable quality until the end of storage period. But, according of sensory analysis results the control samples had lost their quality during three months.

This Study was done in order to evaluate the effect of dietary prebiotic yeast cell wall (Saccharomyces cerevisiae) so called (YCW) on growth indices of Acipenser nudiventris fingerlings. 240 cultural ship fingerlings weighted average number (± SD) 7.61 ± 0.01 g for 8 weeks were fed by four different diets including 0, 0.5, 1 and 1.5% YCW in basal diet in form of 4 treatments (following control, 1, 2 and 3). The treatments in twelve 500L fiberglass tank with density of 20 fish in each tank, in the form of 4 treatments with 3 replicates were randomly distributed. The results showed that growth indices such as final weight, specific growth rate, average daily growth, feed convertion ratio in all treatments had no statisical significant differences in compared with the control (P>0.05). Hepatosomatic index in treatments fed by YCW was significantly higher than control (P 0.05). Condition factor only in treatment 2 was significantly higher than control. Survival rate in all treatments was significantly higher than control. The experiment indicated that YCW didn t influence on growth indices highly in Acipenser nudiventris.

Cheshmekile River in the southem Caspian Sea is an important and valuable habitat for migrating species and birth collect valuable fisheries such as salmon trutta caspius and Rutilus frisii kutuIn. In the present study, to assess the quality of river water Cheshmekile Tonekabon in the year 1389-1390 based on macroinvertebrates Fauna River in mounth studies at four stations within twelve sampling intervals with surber level 0.1m2 and three replicate were performed. Samples collect and fixed with formaldehyde %4, in laboratory have carried sort and enumeration. The study of 47 families belonging to 15 order and six category macroinvertebrate in the River was identified. Indicator of biodiversity in the River is among the highest diversity of aquatic insect larvae simultaneous sampling benthic. Result showed the Order Diptera, Ephemeroptera and Trichoptera that at station 1,2 and Order Diptera, Ephemeroptera and Oligochaeta class (Tubificida, Lumbricida, Lumbriculida and Haplotaxida order) were dominant. Survey Results showed that station 1 with the highest rate of 9.07 gm2 benthos biomasses and station 4 with the average weight of 1.11 g.m2 of the lowest levels allocated of total benthos biomass. Maximum abundance of organisms at this time to station 1 with 44% and minimum of 16% were related to the station 4. kruskal wallis test benthos invertebrates index Order Plecoptera, Trichoptera, Ephemeroptera, Orther stations throughout the year indicates a significant difference is between the confidence level of 95%(p<0.05) but the family Chironomidae at four stations during the year showed no significant differences between stations. Margalef and Shannon Wiener diversity indices of biological highestto lowest scores belonged to station 1 and station 4 is assigned. Shannon wiener diversity index, the diversity of macro benthos in the four stations very slight and small.

This research was carried out over a period of 21 days in September - October 2009 in Shahid Maleki Warm Water Fish Culture Centre in Ahvaz. The aim of the present study was to evaluate cortisol hormone and glucose in response to salinity (1>, 3, 6, 9, 12 ppt) in grass carp, (Ctenopharyngodon idella) fingerlings. Fishes (weight 12.55±0.239 g and total length 10±0.069 cm) were placed in 250 l-tank (15 grass carps/ tank) for 21 days at 24.16±1.35°C. These treatments were tasted in three replicates. At the end of experimental period, blood was collected from the heart for determination of cortisol hormone and glucose. Results indicate that salinity up to 3ppt did not affect cortisol hormone and glucose in grass carp (p>0.05) but higher salinities (6 and 9ppt) adverse effects on cortisol hormone, glucose and survival (p<0.05). At 12ppt all fishes died prior to 14 days. Cortisol and glucose levels significantly increased with increasing salinity indicate that physiological response of fish to salinity stress.