NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2011 | Volume:5 | Issue:2 (18)|Papers Count:19

In this study the effect of salting on liPid and fatty acids of Pike (Esox lucius) and its shelf life were studied for 90 days in 4oc temperature. The identification of fatty acids Profile from fresh and salted Pike was carried out by gaschromatograPhy (GC). Then the changes of fatty acids, Total microbial count, PV and TBA were followed at intervals of 0, 30, 60, 90 days. In fresh Pike sum of the saturated and unsaturated fatty acids were 34.32 and 18.75% respectively. The results showed that with salted fish after 90 days of storage, the saturated fatty acids increased to 36.22 (P>0.05) and the sum of the unsaturated fatty acids due to oxidation decreased to 18.00%. The salting is not only a proper way to conserve, but also by decreasing the fat of the fish from 1.53 to 1.28 % (P>0.05), it will have an effect on preserving fatty acids specially omega3 and omega6. In salted fish the amount of PV increased from 1.84 meqO2/kg to 2.10 meqO2/kg. These results are significant at (P<0.05), In salted fish the amount of TBA increased from 0.05 mg/100g to 0.07 mg/100g after 60 days, then started to decrease and finally reached 0.06 mg/100g after 90 days of storage on 4oc temPerature (P<0.05). The total microbial count did decrease from 1.63 ×102 cfu/g to 1.51×102 cfu/g (P>0.05). This reduction can be due to salting in fish tissues

Fish meat products play an important role in consumption expenditure and in many countries to take advantage of seafood in addition to providing protein needed to earn foreign exchange and solve social problems economic, including unemployment; Therefore, attention to it is more importance. The first report theoretical models and studies discussed, and then select a suitable model for the supply and demand functions of fish in Kermanshah city and using the software package Eviews software has estimated. Model estimation method is Panel-Data. Results indicate to be high price elasticity supply and low price elasticity demand in Kermanshah province. The income elasticity of fish indicates that fish is an essential commodity for households of Kermanshah.

To study toxic phytoplankton Nitzschia seriata (diatoms group) fluctuations, 4146 samples were collected from surface, 2,5,10,20,50 and 100 m depths during 1994-2007 in the southern part of Caspian Sea seasonally. Comparative data (1994-2007) showed that the toxic specimens (Nitzschia seriata) were not observed before 2005, but after 2005, this species appears in some of water layers in southern Caspian Sea. The average of cell abundance and biomass of these species were about 23.41×106±4.25×106 cells/m3 and 23.71±4.81 mg/m3, respectively. The annual survey of cell abundance and biomass about N.setiata showed that the maximum of cell abundance and biomass in 2005 were 39×106 cells/m3 and 39.55 mg/m3, respectively. The most of cell abundance and biomass was observed in spring 2005 and autumn 2004 and its minimum was seen in autumn of 2005 and 2004. The regional survey of this species indicated that the maximum cell abundance and biomass observed in the east region in 2005 and 2007.The middle region was lower in value than other regions (east and west). Therefore, the maximum of N.seritia frequency and bloom were recorded in east and west respectively.

This study was conducted in order to determine the heavy metals concentration Lead and Zinc in muscle and liver tissues of the Otolithes ruber, Scomberomorus guttatus and Scomberomorus commerson at the chemistry laboratory Tarbiat Modares University in 2008. Sampling was done completely randomly and 36 fishes were prepared from the Sarcheshmeh market of Tehran. Metals were extracted from the tissues using wet Digestion method and concentration of the heavy metals was measured by Atomic Absorption Spectrophotometery Philips PU 9400X. The highest concentration of Pb and Zn in the liver of Scomberomorus commerson and Otolithes ruber was 1.13±0.20 and 247±15.71 mg/Kg and the lowest concentration of Pb and Zn in the liver of Scomberomorus guttatus and Scomberomorus commerson was 0.32±0.05 and 0.90±0.02 mg/Kg. This study concentration of heavy metals Zn and Pb in the liver and muscle of Scomberomorus commerson, Otolithes ruber and Scomberomorus guttatus significant difference (P≤0.05).

The survey was carried out at the Shahid Bahonar Kalardasht Salmonids Reproduction Center (KSRC) during spawning season at 2009. A number of nine mature males (three years old) and 11 female Caspian brown trout,grown in the Salmonids Reproduction Center, were used. In the first stage all of male brood stocks (9 male) striped sperm sampling separately. Fertilization was made with each group’s sperm mixture and striped eggs in part of the five female and then eggs hardness process, transferred to the three trays in an incubation trays then the incubation process trends were evaluated. 14 days after the first stage, the second stage of sperm stripping occurred and 27 days after the second stage, third stage of sperm stripping as well as making first phase sperm stripping was implemented for each stage group of the three females. At the end of each three stages of sperm stripping, sperm density, spermatocrit percentage, sperm volume, sperm motility and morphology of spermatozoa (percentage of abnormal spermatozoa) were recorded and investigated. Their effects on fertilization rate, eyed eggs, hatching rate and larvae survival during repetitive sperm extraction were measures. The results showed that there were significant differences between the volume, motility, sperm morphology and fertilization rate during third phase of the study (P<0.05). The highest fertilization rate observed in the first stage of sperm extraction (97.33±1.53%) and lowest fertilization rate observed in the third stage of sperm extraction (7.25±6.25%). In this study, sperm density, spermatocrit, the percentage of eyed eggs, hatching and larvae survival in all the third stage was not significantly different (P>0.05). However, due to LSD test, percent survival of larvae had differences in stage 2 and 3.

This study was carried out in Sefidroud Fisheries Research Station in Astaneh-Ashrafieh city in 2009. The research was conducted to assess the effect of 5 pure dietary of Isonitrogenous and Isoenergetics with different protein sources. The test followed a Randomized complete design. Each treatment was organized with 4 replicates and totally 20 rearing tanks were involved. The period of test was planned for 60 days and the test organism was housed in fiber-glass tanks of 110 l capacity. The main sources of protein in test diets were fish meal (F) and soybean meal (S), as fish meal was replaced by soybean meal in each treatment. Test diets consisted of F100/S0 F70/S30, F50/S50, F30/S70 and F0/S100 fish meal per soybean meal percent. Daily Feeding was planned on 3% of body weight and similar in each treatment. The results showed that with increment of fish meal level in proportion to Soybean meal in experimental diets the indices of growth of Rutilus frisii kutum concerning body weight, specific growth rates, food conversion ratio and protein efficiency ratio improved. As in a diet with 100 and 70 % fish meal maximum improvement of vital factors were achieved. Survival ratio (100%) was similar in all of the diets. The diet of F100/S0 and F70/S30 had no significant differences, so it is worthto replace 30% of fish meal with soybean meal in kutum diet for maximum growth and optimum economically point of view.

During 13 months of sampling (September 2009 to Sep 2010), 809 Spirlins (Alburnoides bipunctatus) were caught from Mazandaran Talar river from which 412 spirlins belonged to Keselian cluster and 397 spirlins belonged to Tejoon cluster. Fishing was performed by a 250-300 volts electro-shocking machine. The assessments showed 30 morphometric and 10 meristic specifications. The result of t-test indicated a meaningful difference in 13 morphometric & 7 meristic specifications between spirlin fish of The Two clusters (P≤0.05). Four age classes were observed in spirlin population in which the age group of 2⁺ was the most abundant (49%). Also, in general, the total population consisted of female fish (50%), male fish (39%) and immature fish (11%). The maximum length in this research was 96.14 mm and the maximum weight was 9.27 grms. The relationship between length-weight showed a high correlation between Keselian cluster (r2=0.98) and Tejoon (r2=0.97). The conditional factor indicated the obesity of most Keselian species. The growth pattern has shown a negative alometric pattern in spirlin species of the two clusters and Instant growth rate of immature species has been more compared to other age groups. It can be concluded that Spirlins of the two clusters have some differences considering some morphplogical specifications and for a more complete population segregation of this species, modern genetic methods must be used such as PCR, Electrophoresis and micro satellite.

This study was carried out in the south–west Caspian Sea (in coastal of Kiashahr waters) form September 2007 until May 2008 on Vimba vimba species of Cyprinidae. The samplings were monthly and samples were collected by several fishing gears beach seine. 415 specimens of Vimba vimba were caught. The measured parameters were: TL, FL, SL, body weight, age (using scales) and sex. All studied fishes were classified in 3 age groups (1+, 2+, 3+) years. Mean fork length and mean body weight of males were 164±16.17mm and 60.7±21.23gr, respectively, and in females were 183±17.68 mm and 89.4±26.88gr, respectively. Most of the fishes (84.8%) were 2+ years old and the least (0.48 %) were 3+ years old. Sex determination of 412 fishes showed that 42% of them were males and 58 % were females with a ratio of 1 to 1.38. Mean fat rate and condition factor (CF) in males and females were 0.98±0.07 and 1.04±0.08, respectively.

Carotenoids are widely being used in medical applications, foods, additive substances and cosmetic materials as colors, anti-oxidants and anti-cancers. Dunaliella as a natural source of mass concentration of carotenoids is considered. In this study, the effect of various salt concentrations of 5, 10, 15, 20, 25, 30, 35 and 40% on production of Beta Carotene in Dunaliella Salina microalgae was evaluated. Dunaliella Salina was isolated from Shahe Lake located in south of Tehran and was purified. The dense growth was performed in altered Janson medium. The flasks containing medium culture were cultured in suitable conditions. To evaluate beta carotene, the obtained extracts from samples were analyzed by HPLC. The results obtained from analysis of algae samples with different saltiness (0, 5, 10, 15, 20, 25, 30, 35 and 40%) in their culture medium showed a meaningful difference (0.0001) on production amount of beta carotene. The maximum production amount of beta carotene was 0.33 microgram in liter in saltiness of 25%. The observed results from this study showed that by increasing various concentrations in medium culture of this alga until %25 the production of beta carotene increased.

In this study, the population structure and assembly of Benthic in Kslyan have been studied. Kslyan is an important branch of River Talar. The total of eight stations on the river route was selected and large Benthic were sampled monthly during one year by Surber sampler with three replicates. Samples were collected with 4% formalin fixation and isolation and were counted in the laboratory. 31 families in the Great River Benthic were identified from which aquatic insect larvae were the most frequent. Persons from these three orders Diptera and Ephemeroptera and Trichoptera were the most dominant organisms in all stations. The order Diptera's frequency variation shows that many families in the two stations Chironumidae 4 and 8 had a significant increase which was due to urban pollution before entering the two stations to river. Among the orders Ephemeroptera, Baetidae and Ecdyonuridae, two families were present in all stations. The results showed that the orders Trichoptera and Hydropsychidae were the dominant family. The orders above show significant differences (P<0.001) among the stations. Results indicated that the nature has managed to compensate for the natural changes in population composition of Benthic.

Karganrud River which is in south-west Caspian Sea is important for spawning of anadromous fishes, feeding of estuary fishes and special fish population, too. Main purposes of this study were: Identification of fishes and their abundance, diversity, richness and evennes indices and present role of the river in restocking. Studied fishes have been sampled in 7 stations from fall 2001 until summer 2002 using with Electric gear, cast net and beach seine. Results showed 18 fish species belong to 8 families exist in the river so that Cyprinidae with 10 species and 90.05 % of total populations was dominant. Alburnoides eichwaldi, Capoeta capoeta and Alburnus hohenackeri with 29.58%, 29.15% and 19.87% were dominant, respectively. There were 10 species of freshwater resident species, 4 species of migratory or anadromous fishes and 4 species of marine or estuary fishes in Karganrud River and in the river were identified 5 alein species, too. Shannon species diversity was determined minimum in autumn, (1.050) and maximum in summer (1.679), Margalef species richness was minimum in autumn (0.635) and maximum in summer (2.228) and Peilo species index was minimum in summer (0.593) and maximum in autumn (6.520) and these indices had changes in related to station changes. This study showed Karganrud River is potentially a suitable river for anadromous fishes restoring in south Caspian Sea.

In this research, the effect of probiotic Vanagen as growth and safety stimulator on growth factors and survival of rainbow trout fingerling is investigated in two months. Treatments included four levels of Vanagen (0.62, 1.25, 2.5, 5 gr per kg feed) and a control. The experiment was conducted in fifteen circular concrete lavers (3 meter in diameter and 1.5 meter depth) located in Arak Mutation and Growth Workshop of Sardabi Ghezel Parvar Fish. 100 rainbow trout fingerlings (average weight 22±1 gr) were stocked in each laver. The fish were fed about /.3 of their body weight, four times per days. Biometry factors were observers every ten days. The survey of growth factor indicates the most body weight growth in 5-gr Vanagen treatment (=49 grams increase). But there was no significant difference in 2.5-gr Vanagen treatment P>0.05 level. The results showed that the most survival rate was observed in 2.5-gr Vanagen treatment (92.3) which showed a significant difference in 0.62-gr Vanagen treatment P<0.05. The addition of Vanagen led to improvement in: body weight¸ survival¸ percent body weight, specific growth rate, protein efficiency ratio, feed conversion ratio, daily growth index.

Anesthesia drugs are used in many cases for farmed aquatic animals especially in fishes. In this study, anesthesia effect of clove powder was evaluated in 0.5, 0.7 and 0.8 gr/lit concentrations on 30 farmed Huso huso 4 years old in order to use in surgery. Results showed that the mean time for anesthesia and recovery in 0.5 gr/lit of clove was 10 and 3.5 minutes, respectively. The mean time for anesthesia and recovery in 0.7 gr/lit of clove was 7.5 and 4 minutes, respectively. The mean time for anesthesia and recovery in 0.8 gr/lit was 6 and 5 minutes, respectively. The One–way ANOVA statistical analysis and Tukey test showed that there was a significant difference between concentrations 0.5 gr/lit with 0.7 and 0.8 gr/lit (P<0.05). But there was not a significant difference between 0.7 and 0.8 gr/lit concentrations. Also, there was a significant difference between 0.5 and 0.8 gr/lit about recovery time and there was not any significant different between 0.7 gr/lit with others (P>0.05). Considering these results, concentration 0.7 gr/lit of Clove is better than other concentrations for anesthesia in farmed 4-year-old Huso huso.

Many organisms such as parasites cause damage to fish. Lack of legislature and perception for aquatic disease led to the expansion of many dangerous diseases. In some cases, his has led to the collapse of aquaculture in some countries. One of vectors the parasite infection are nonindigenous fishes. This study had carried out to survey on gastric infection of amorcheh (Pseudorasbora parva) by plerocercoid of Ligula intestinalis in Zabol Chahnimeh Reservoirs. This survey was carried out on 108 fish samples during three months, i.e. March, April and May in 2008. Based on the results breakout rates, frequency and mean infection density were 18.44%, 13.88% and 1.4% respectively. Maximum number of parasites in a sample was 4 and the largest parasites observed were 5.84 centimeters. Also it was observed that between sampling months the maximum rate of breakout was in March.

This research was carried out over a period of 90 days in the summer and autumn of 2009 in the Mazandaran Acecr Fingerlings of Cichlasoma nigrofasciatum. 4-6 gr were transferred to 32- liter Aquarium each stock with 75 fish. The treated with 4 treatments and 3 replicates including, fresh water, 8ppt, 10 ppt and 12ppt salinity by completely randomized design. We found that different salinity did not affect the mortality rate of the fish. Comparison of food conversion ratio (FCR), special growth rate (SGR) between control and other treatments showed a significant difference (P≤0.05). We also found that control treatment differed meaningfully with 8ppt, 10ppt and 12ppt treatments in terms of FCR and SGR and the same was true between 8ppt, 10ppt and 12ppt treatment for the FCR and SGr. The results showed that the maximum and minimum weight gain were related to 8ppt treatment (mean 7.74) and 12ppt (mean 5.8) respectively. The minimum special growth rate (0.002) was reffered to the control and 10ppt treatment and the maximum (0.003) was seen in 8 and 12ppt salinity. According to the results, it is suggested that the optimal salinity for fingerlings with mean weigth 4-6 gr is 8ppt.