NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2011 | Volume:5 | Issue:3 (19)|Papers Count:17

This project was carried out to preserve the quality of Kilka Fish in cold storage. This project was carried out in three replicates and formulae. The aim of this research was to assess the posibility of using edible film for dressed Kilka packaging and its quality assessment including food nutritive and bacterial, chemical and sensory properties. For fish packaging 6% concentration of whey protein was used. Kilka without covering was used as control sample.The samples were kept at -18oC for a period of six months. Total bacterial counts and Staphylococcus bacteria count were lower in the covered samples at 0 (2.96 and 1.56 logCFU/g) compared with the other samples and were higher in 2 hour samples (3.21 and 2.26 logCFU/g) compared with the other samples. Coliform, Escherichia coli and Pseudomonas bacterial contamination were not observed in the samples. Moisture was lower in the covered samples at time 0 compared with the covered samples at 4 hour sample (70.14 and 72.73%). Peroxide value, free fatty acids, thiobarbitoric acid, TVN and pH were higher in these samples compared with the covered samples at 4 hour samples (2.13 and 1.70 meq/kgoil, 3.75 and 2.44 g/100, 0.02 and 0.01 mg/kg, 16.9 and 12.48 mg/100g and 6.37 and 6.20). Protein, fat and ash were higher in the covered samples at 4 hour samples (19.25%, 4.83%, 2.97%) compared with the other samples. A statistically significant difference was observed in chemical and bacterial factors in the samples (P<0.05). Sensory analysis was carried out by ranking method. In overall acceptable score there was a 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.

In this study, an experiment of 60 days was carried out to evaluate the effect of L-alanine amino acids dietary on some blood parameters of Persian sturgeon (Acipenser persicus). To this end, 96 fish (initial mean weight: 23.5 gr) were fed a basal diet with 54% crude protein for a conditioning period of 8 Week. Following conditioning, fish were stocked as groups of 8 in twelve 500 lit fiberglass tanks and fed the basal diet and experimental diets supplemented with 1,2, and 3% L-alanin for a period of 8 weeks. The groups were tested in triplicate. The fish were fed 4 times a day based on 4% of their biomass. At the beginning of the period, blood samples were taken from some of the fish with syringe from caudal peduncle area. At the end, blood samples were collected from 24 fish (2 fish from each tank) in order to determine and analyse the most important parameters of blood such as the amount of packed cell volume (PCV), eosinophils, notrophiles, lymphocytes, monocytes, hemoglobin (Hb), erythrocyte count (RBC), leucocyte count (WBC), mean corpuscle volume (MCV), mean corpuscle hemoglobin concentration (MCHC) and mean corpuscular haemoglobin (MCH) assessed. Blood haematological indicator with the exception of lymphocytes, monocytes, PCV and MCH showed significant differences among different attendances of L-alanin (P<0.05). The results of this study showed that application of L-alanine can affect growth performance and some blood indices in Persian sturgeon.

Brown trout is a vulnerable subspecies of the Caspian trout fish which usually exists in the upstreams of the Caspian Sea basin Rivers, Lighvan-Chai (East Azaarbaijan) and Karaj reservoir. The fish has a good stock in Lar reservoir of Mazandaran province and 17862 license items were issued for catching the fish in summer 2006. The aim of this study was to determine the morphometric, meristic and descriptive characteristics of the fish in Lar reservoir and 190 specimens have been caught by electroshocker in Elarm, Ab-Sefid, Kamardasht and Delichai Rivers in autmn 2008 and summer and autumn 2009 and they were measured. The average weight and fork length of the studied specimens (n=190) was 136.86±103.4 g and 212.81±49.6 mm respectively. The results showed that there were 108-134 scales on lateral line, 2-5 unbranched and 8-11 branched rays in dorsal fin, respectively, 2-5 unbranched and 6-9 branched rays in anal fin, respectively and 15-21 gill rakers in first gill arch and 57-60 vertebrae, among 17 meristic count in brown trout. Among 31 measurement factors, the measured averages were as follow: head length 22.34±1.4, depth of head 14.80±1.1, maximum depth of body 20.87±1.7, base length of dorsal fin 12.52±1.2, pectoral fin length 15.60±1.2, ventral fin length 12.39±1.0, base length of anal fin 9.38±0.9, pre-dorsal distance 41.24±1.9 and pre-ventral distance 46.84±2.3% of fork length. There were no significant differences in meristic counts between male and female but there were observed 18 differnces in morphometric factors between two sexes, so that there was difference in 9 factors in a=0.001 level, 5 factors in a=0.01 level and 4 factors in a=0.05 level. In conclusion, it can be said that the results of the current morphomeristic data have many differences with investigations carried out in the Republic of Azarbaijan and certainly stock of Lar reservoir is a distinct population.

The Oshmak River is one of the most important rivers in Gilan province that passes from Kochesfehan, Lashtenesha and Zibakenar and joins the International Wetland of Boojagh, and then flows into the Caspian Sea through theNational Park of Boojagh. Parameters of Physical, Chemical and Microbial of Oshmak River were measured from spring 2006- winter 2007. For this purpose, according to standard methods, Water parameters were measured from 6 selected stations seasonally. According to the results, mean of Air Temperature was 19.63oC, mean of Water Temperature was 65.17oC, mean of Turbidity was 29.40 FTU, mean of Conductivity was 1114.95 micromus/cm, mean of TDS was 678.03 mg/l, mean of TSS was 38.58 mg/l, mean of Total Alkalinity was 77.75 mg/l, mean of Total Hardness was 412.25 mg/l, mean of Ca+2 was 68.14 mg/l, mean of Mg+2 was 60.44 mg/l, mean of Cl- was 133.45 mg/l, mean of So4-2 was 152.64 mg/l, mean of Po4 was 0.08 mg/l, mean of Total Phosphate was 0.63 mg/l, mean of NH4 was 0.34 mg/l, mean of No2 was 0.05 mg/l, mean of No3 was 0.81 mg/l, mean of Dissolve Oxygen was 7.24 mg/l, mean of BOD was 9.83 mg/l, mean of COD was 34.61 mg/l, mean of Salinity was 490 mg/l, mean of pH was 7.75, mean of Acidity was 5.50 mg/l, mean of Free Co2 was 4.48 mg/l, mean of Total Coliform was 33541 no/100 ml/l and mean of Fecal Coliform was 5363 no/100 ml/l.

In order to study biomass and length frequency of 3 main species of Saurida tumbil, Psettodes erumei and Grammoplites suppositus, a research cruise was carried out in the Persian Gulf, Systan and Balochestan waters using swept area method in 2000. The studied area was from Meidani (58˚ 55′ E) to Gwatre Bay (61˚30′ E) having depths of 10 to 100m. The studied area of 1164 n.m.sqr., was divided into 5 subregions (A, B, C, D and E) each covering 30 minutes width, each region was divided into 4 depth stratum: 10-20, 20-30, 30-50 and 50-100 m. In each cruise, sampling was carried out for more than 65 stations using a bottom trawler by R/V Ferdows. And then the following measurements such as the sampling of demersal species were carried out. The calculated annual biomass for the whole area was 41830.3 tons in 2000, and for each stratum of 10-20, 20-30, 30-50 and 50-100 m, indicating 22393.5, 5492.9, 1398.1 and 12545.7 tons respectively. It is clear that the maximum biomass lies at the depth of 10-20 m. The minimum was found at depth of 30-50 m. After the samples were identified, weighted and also some biological measurements were done. All data were analyzed by Excel, and were presented as figures and total biomass was estimated seperately in depth and area. The total biomass of Saurida tumbil, Psettodes erumei and Grammoplites suppositus, were estimated about 847.3, 162.4 and 279.9 tons, respectively. On the other hand the most length frequency of this species was found in length of 32-35 cm, 35-40 cm and 14-16 cm, respectively.

  The aim of this research was to study the biotechnique of partial harvest method and its efficiency in enhancing the production of Indian white shrimp (Fenerropenaeus indicus) culture in Gwater center, Chabahar, Iran. To this end, partial harvest was carried out in 3 farms, and its results were compared with two and single crop farms. Each pond (1.1 ha) of partial harvest farms were stocked with 240 thousand PL with a density of 22/m2. At the 108th day of culture (DOC), nearly 6304 kg was partially harvested from each farm. The final harvest was done in DOC 138. The average body weight of harvested shrimp in partial harvest and final harvest was 11.6 and 14.9 respectively. Mean total production of each farm and production per hectare was 36626 and 2304 kg respectively. The data gathered by this study showed that the annual yield mean of partially harvested farms was near 6 mt more than single crop farms, but 11 mt lower than two-crop farms. Based on the results of this study, a program for partial harvest in the future is suggested.

This research was conducted to make oral type of 17-a methyl testosterone hormone produced fry mollies neomale sex population in three different doses of 17-a methyl testosterone hormone at four treatments and three repeats within 60 days in fall-winter 1388. At the end of the experiment, morphologic and histology of the fish were studied and Special Growth Rate (SGR) & Amount of Diurnal Growth (ADG) and Wasting percent, neomale production percent, Hermaphrodites percent, sterilization percent were studied to determine the best dose in commercial production, The results showed that having 200 mg hormone per every one kilo/g food which created 97.06% male fish in morphologic view and 90% of male fish in histology and 14.38% waste wth the maximum SGR & ADG is the most useful. (P<0.05) Also using 300 m/g hormones of foods, despite creating a complete male population in morphology’s view and 90% of male population in histology’s searches, makes the highest waste.

This study was carried out to determine the effect of size of Barbus grypus broodstock on functional fecundity, fertilization rate, hatching rate and larvae survival rate. Three female groups (treatments) were chosen for breeding. Treatment1: 2212.5 ±780 gr, treatment 2 :4518±780 gr and treatment 3: 7712.5±171 gr. There were the same male broodstocks for all treatments (1400±100 gr). Female broodstocks were injected with 3 mg/kg of PG hormone in two stage with an interval of 10 hours. Males were injected with 2 mg/kg in one time of females second injection. Functional Fecundity, fertilization rate%, hatch rate%, larvae survival rate% indices were calculated for all treatments. Maximum functional fecundity (13000.37±4651.57), fertilized egg (94±1.51%), hatching rate (83.62±2.77%) and larvae survival rate (84.75±1.28%) were observed in treatment 2. Minimum functional fecundity, fertilization rate%, hatching rate%, larvae survival rate% were 4879±2325.29 (treatment 3), 82.66±10.48 (treatment 1), 64.16±3.65 (treatment 1) and 71.6±1.63 (treatment 1) respectively. With the increase of broodstock weight until 4518±780 gr reproductive indicies increaced and beyond that decreased. In all of indicies treatment 2 showed significant diferences with other treatments (P<0.05). So treatment 2 is the best treatment compared to other treatments.

During a project, carried out within 35 days, the effect of water flow increment on rainbow trout culture was surveyed by reusing the outlet effluent under a Complete Random Design with 4 treatments and 3 repeats. The factors studied were Weight, Length, Specific Growth Rate (SGR), Daily Growth Rate (DGR), Condition Factor (CF) and the Survival Rate (SR) in culture fishes. Fry initial weight and body length were 5.5 gr and 6.7 cm respectively. The treatments consisted of various water velocities including 0, 3.5, 7 and 10.5 cm/s. The results of variance analysis of surveyed fry factors showed very significant differences among all treatments during the first week (P<0.01). However, these results were not observed in other weeks. On the other hand, the results of data variance Analysis of the factors through all 35 days period experiment showed significant differences among all treatments regarding all the fry factors except for Length and Condition factor. The results of Duncan’s test of surveyed factors among a 35 days period showed that the best average Weight (24gr), SGR (6%), Daily growth rate (1) and Survival Rate (97%) were achieved in 10 cm/s treatment but about fry Length factor, all treatments were equal.

We assessed and compared the concentration of heavy metals Mn, Zn, Fe and Cu in the muscle, liver and gill tissues of Liza abu in the Karkheh River in Khoozestan Province in winter 2009. Muscle tissue, liver and gills of 36 specimens were separated after bioassay. The study measured metal concentrations by wet Digestion Method using Atomic Absorption Spectrophotometry Perkin Elmer4100 in the laboratory of Alborz project in Shahrekord. This study showed that the average concentration of heavy metal in muscle tissue was the highest and in gill tissue the lowest. Iron concentration was more than zinc, manganese and copper in different organs of Liza abu (P≤0.05). Among metallic Iron accumulation in muscle tissue, liver and gills there was a positive linear relationship (P≤0.05). Manganese and copper in muscle and liver had no significant differences. However, there was a significant difference between muscle and liver with gill (P≤0.05). Zinc in the liver, gill and muscle had no significant difference (P≥0.05). The results of heavy metals in fish muscle and its comparison with standards Liza abu, UK (MAFF), WHO, FDA, NHMRC and NFA puppet showed manganese and iron metal contamination compared to WHO and FDA standards is.

To investigate the possibility of using two-purpose warm water fish farms to produce earth worm as a live food, an experiment was conducted which 3 tons of organic fertilizer were used in it for worm culture. The fertilizer was divided among 3 plots with 1×12 m² dimension. 50 worms were introduced to each quadratic meter of fertilizer surface as early stock. 36 Kg earth worm was produced through 3 months in fertilizers. The effects of reared worms on growth of common carp (Cyprinus carpio) were studied during a 2 months period and in CRB with 2 treatments and 6 repeats. The plots were 12 net cages with 1.5×1×1.5 meter dimension without bed. 10 fry were introduced to each plot. The initial weight and length of fries were respectively 30 g and 91 mm. commercial food (4%) and mixture of earth worm and commercial food (1% worm + 3% commercial food) formed the treatments. The results showed very significant differences between 2 treatments about length, weight and Daily Growth Rate (DGR), (P<0.01) but about Specific Growth Rate (SGR) significant differences were observed only through early 15 day of experiment. The best averages of total length (278 mm), weight (266.4 g), DGR (5.3 g), SGR (2.36%) and coefficient of fatness (1.36) were shown in mixture food treatment. The results showed that integrated carp and earth worm producing in farms are totally possible.

To preserve the diversity of sturgeon species and maintain their number, a great deal of attention has been paid to artificial propagation in recent years. One of the most important points in propagation is the environmental condition. In this study, the effects of water flow on the incubation of the eggs of Acipenser persicus were investigated. Four water speeds (2.4, 3.4, 4.4, 5.4 lit/min) were examined. These speeds were arranged with zigzag boards in yoshchenco incubator. 1000 g eggs were transferred to each tray. For each speed, 4 trays were selected. First number of eggs in one gram before and after fertilizing was determined. Then percentage of fertilization at the 2nd division stage was determined, 80-84-82-75%. After 4 days the eggs hatched. Hatch percentage was determined. With speed 2.4 fungus percentage was higher and hatch percentage lower. 3.4 lit/min is the best speed because of the highest number of larva, and this speed is longer than others. 4.4 lit/min was lower and finally in 5.4 lit /min all of the eggs were lost because of high speed.