107 research outputs found

    Chemical composition and fatty acid profile of common Kilka , Clupeonella cultriventris caspia

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    The objective of the present study was to determine chemical composition and fatty acid profile of common Kilka ,Clupeonella cultriventris caspia, in the Caspian Sea. The chemical analysis revealed that the protein and lipid content of common Kilka were 15.05 and 6.5% of the fresh weight, and total MUFA, PUFA and SFA were found to be 37.00, 32.89 and 29.03% respectively. Palmitic acid (16:0) among total SFAs, oleic acid (18:1n-9) among MUFAs, Docosahexanoid acid (DHA) (22:6n-3) among n-3 PUFAs and linoleic acid (LA) (18:2n-6) among n-6 PUFAs were the most abundant fatty acids. The obtained results revealed that common Kilka is a better source of ω-3 PUFAs than ω-6. DHA and eicosapentaenoic acid (EPA) were the major components of ω-3 PUFAs. Levels of DHA and EPA were 20.79% and 6.97% respectively. The PUFA/SFA ratio was 1.13 in common Kilka. This ratio was more than the recommended minimum value (0.45).The EPA/DHA ratio was 0.34 in common Kilka. The present study suggests that common Kilka is rich in essential unsaturated fatty acids of the ω-3 family, especially DHA which may be considered nutritionally attractive for human

    Microscopic structure of the intestine of beluga (Huso huso) from hatching until ranching to sea

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    Microscopic structure of intestine of beluga was studied from hatching until releasing to sea. Larvae were fixed in bouin’s solution, dehydrated and embedded in paraffin wax. Sections of 5-7 μm thick were produced and stained according to standard histological techniques: Hematoxylin-Eosin (HαE) and Periodic Acid Schiff (PAS). One day old larvae possessed a primordial intestine, which is lined by a simple columnar ciliated epithelium. At 3 days after hatching, an oblique furrow of the digestive tube wall started to develop on the dorsal- posterior region of the yolk sac and divided the alimentary canal into two differentiated regions: the future stomach and intermediate intestine. At this time spiral valve started to differentiate. Granules of embryonic pigment accumulated in the spiral valve lumen forming the melanin plug. At 7 days after hatching intermediate gut and spiral gut were lined by a columnar ciliated epithelium. The terminal section of the digestive tract was differentiated into a short rectal duct lined with a cuboidal epithelium. The urinary bladder connected with rectum at this time. At 13 days after hatching the number of vacuoles filled with lipid increase in intermediate gut and spiral gut. Between 17-19 days post hatching beluga larvae have a period of mixed nutrition. At 25 days after hatching cells of intermediate gut showed long microvilli. At 36 days after hatching the number of goblet cells increased in spiral gut. At 43 days after hatching several intestine glands were visible in connective tissue of intermediate gut which was lined by a simple columnar ciliated epithelium. Between 57-75 days after hatching the number and size of mucosal folds increased in intestine. This information may be useful to improve rearing efficiency of beluga and the other sturgeons

    Investigation osmoregulation system of the Persian sturgeon released in the Gorgan River

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    In this study, circumstances of osmoregulation system of the Persian sturgeon released in the Gorgan River in order to stock restoration have been investigated. Ten days old larvae sampled during 45 days from hatchery to the estuary. Samples taken form blood serum, gills and kidney tissues were collected from 12 May to 26 June, 2003. In the present study, Sampling sites were Shahid Marjani sturgeon hatchery, earthen pond, river water (2 sub samples ) and estuary. The blood serum osmotic pressure ( mOsm/L) , K^ + , Na^+, Mg^++ ( mEqu/l) and Ca^++ (mg/dl) concentration were measured. In order to investigate the condition of osmoregulatory cells development, histological experiments of the specific tissues have been taken place accordingly.Regarding to figs. (1,2,3,4,5,6,7,8,9,10) , osmotic pressure of blood plasma was higher than the water ( the difference range is 14- 196 mOsmol/l). Statistical results (test of one way t student) show significant differences between the medium osmotic pressures (P=0.99). In cases of ions, the concentration of Na^+ and K^+ were higher than those of the water. There is also significant difference between these ions concentration (P = 0.01).In contrast, the content of Mg^ ++ and Ca^++ were lower than the water. Regarding to these last two ions, there is also significant difference (P= 0.99). Histological experiments confirm the results and show a relative development of the osmoregulatory cells in gills and kidney in accordance with fish ages

    Principal component approach in variance component estimation for international sire evaluation

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    <p>Abstract</p> <p>Background</p> <p>The dairy cattle breeding industry is a highly globalized business, which needs internationally comparable and reliable breeding values of sires. The international Bull Evaluation Service, Interbull, was established in 1983 to respond to this need. Currently, Interbull performs multiple-trait across country evaluations (MACE) for several traits and breeds in dairy cattle and provides international breeding values to its member countries. Estimating parameters for MACE is challenging since the structure of datasets and conventional use of multiple-trait models easily result in over-parameterized genetic covariance matrices. The number of parameters to be estimated can be reduced by taking into account only the leading principal components of the traits considered. For MACE, this is readily implemented in a random regression model.</p> <p>Methods</p> <p>This article compares two principal component approaches to estimate variance components for MACE using real datasets. The methods tested were a REML approach that directly estimates the genetic principal components (direct PC) and the so-called bottom-up REML approach (bottom-up PC), in which traits are sequentially added to the analysis and the statistically significant genetic principal components are retained. Furthermore, this article evaluates the utility of the bottom-up PC approach to determine the appropriate rank of the (co)variance matrix.</p> <p>Results</p> <p>Our study demonstrates the usefulness of both approaches and shows that they can be applied to large multi-country models considering all concerned countries simultaneously. These strategies can thus replace the current practice of estimating the covariance components required through a series of analyses involving selected subsets of traits. Our results support the importance of using the appropriate rank in the genetic (co)variance matrix. Using too low a rank resulted in biased parameter estimates, whereas too high a rank did not result in bias, but increased standard errors of the estimates and notably the computing time.</p> <p>Conclusions</p> <p>In terms of estimation's accuracy, both principal component approaches performed equally well and permitted the use of more parsimonious models through random regression MACE. The advantage of the bottom-up PC approach is that it does not need any previous knowledge on the rank. However, with a predetermined rank, the direct PC approach needs less computing time than the bottom-up PC.</p

    Study on rearing movine carps in the ponds of brackish water and freshwater

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    In this study, mono culture of Cyprinus carpio in fresh water and brackish water with 3500 specimens per hectare with 3 replication each carriedout from midel April to end the October 2010 and mide april to end the October 2011 recptively. Juline fish with 40 gr weight takeup from the sade voshmgir and after prepara tion of rearing ponds were introduced to pond according to appropriate and caluclate stocking density. Juline were fed by concentracted food(GFC). Feeding calculation based on percentage of body weight varied from 5 to 10 % of body weight. In fresh water Average weight and lenghth were in the stage time stocking 40 gr 14.68 cm and at the end of cultuivation period were 704.26 gr and 37.04 cm respectively. Inorder to comparecultivation of Cyprinus carpio in freshwater with breackish water another stocking 350 specimens per hactar with 3 replications also tookplace in this study. Junlin fish with average weight of 40gr and average length of 14.12cm were introduced to the ponds. At the end of rearing period average final weight was 700.26 with average length of 38.86cm.mean daily growth in fresh water treatment was 3.39. in brackish water replication the average daily . average condition factor in fresh water was 2.41. The average value CF in breackishwater was 1.39. in this research was survival rate in the fresh water and breackish water were more 77%

    Ecological study on fisheries important rivers and bays in the south part of the Caspian Sea 2nd phase: Gorgan Bay

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    In this study ichthyoplankton, phytoplankton, zooplankton, benthic and hydrochemistry parameters were studied. 9 out of 11 sampling stations were in the Gorgan Bay area and 2 of them were in the mouth of the Bay. Ichthyoplankton survey were carried out in 6 stations and the other surveys such as phytoplankton, etc were done in 11 stations in 2009. Gorgan Bay map and position of sampling sites are given at the end of material and methods section. Biomass and frequency of phytoplankton at different stations, months and seasons were calculated that are presented in Tables 1 to 3. Hydro-chemical parameters such as water temperature, air temperature, visibility, DO, BOD5, pH, Alkalinity (bicarbonate, carbonate and total), Hardness (calcium, magnesium), CL,EC, Salinity, N (nitrate, nitrite, NH_3), Phosphate were measured and results are shown Table 11. Biomass (mgr/m^3) and numbers (ind./m^3) of 47 genus of different phylum of phytoplanktons such as Cyanophyta, Chlorophyta, Pyrophyta, Chrysophyta and Euglenaphyta as well as different phylum of zooplanktons consist of Protozoa, Arthropoda, Rotifera and Cyliophora were estimated. Frequency of phytoplanktons (ind/m^3) was 131.2, 1.6, 65.3, 18.9 and 23.8 million respectively. Furthermore, their biomass was 308.4, 1.9, 1358.9, 295.1 and 124.7 mg/m^3, respectively. The maximum and minimum numbers were observed in Leptolingbaya belonged to Cyanophyta and Diatoms of Chrysophyta 84.3 and 0.025 million (ind/ m^3) respectively. The maximum and minimum biomass was observed in Gyrosigma (Chrysophyta) and Tetradron (Chloropyta), 12317.3 and 0.014 mg/m3 respectively. The average biomass of zooplankton was measured 531.74, 30.77, 225.07, and 96.26 mg/m^3 respectively and the total was attained 883.83 mg/m3 Table 5. The maximum and minimum biomass of all zooplanktons was estimated in November and July, 3446.23 and 6 mg/m^3 respectively. Furthermore, the maximum and minimum numbers of zooplanktons were found in September and July which were 48.4 and 0.002 millions respectively and the average number was 8.4 ind/m^3 Table 4. Also numbers and biomass (gr/m^2) of 11 families of benthos which inhabit Gorgan Bay such as Annelida, Mollusca and Arthropoda were investigated in separated stations and distinctive months. The maximum and minimum biomass of benthos was observed in January (42.91 gr/m^2) and March (0.6428 gr/m^2). The biomass was considerable in April, February, August and December (Tables: 4, 5 and 6)

    Mapping targets for small nucleolar RNAs in yeast

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    Background: Recent analyses implicate changes in the expression of the box C/D class of small nucleolar RNAs (snoRNAs) in several human diseases. Methods: Here we report the identification of potential novel RNA targets for box C/D snoRNAs in budding yeast, using the approach of UV crosslinking and sequencing of hybrids (CLASH) with the snoRNP proteins Nop1, Nop56 and Nop58. We also developed a bioinformatics approach to filter snoRNA-target interactions for bona fide methylation guide interactions. Results: We recovered 241,420 hybrids, out of which 190,597 were classed as reproducible, high energy hybrids. As expected, the majority of snoRNA interactions were with the ribosomal RNAs (rRNAs). Following filtering, 117,047 reproducible hybrids included 51 of the 55 reported rRNA methylation sites. The majority of interactions at methylation sites were predicted to guide methylation. However, competing, potentially regulatory, binding was also identified. In marked contrast, following CLASH performed with the RNA helicase Mtr4 only 7% of snoRNA-rRNA interactions recovered were predicted to guide methylation. We propose that Mtr4 functions in dissociating inappropriate snoRNA-target interactions. Numerous snoRNA-snoRNA interactions were recovered, indicating potential cross regulation. The snoRNAs snR4 and snR45 were recently implicated in site-directed rRNA acetylation, and hybrids were identified adjacent to the acetylation sites. We also identified 1,368 reproducible snoRNA-mRNA interactions, representing 448 sites of interaction involving 39 snoRNAs and 382 mRNAs. Depletion of the snoRNAs U3, U14 or snR4 each altered the levels of numerous mRNAs. Targets identified by CLASH were over-represented among these species, but causality has yet to be established. Conclusions: Systematic mapping of snoRNA-target binding provides a catalogue of high-confidence binding sites and indicates numerous potential regulatory interactions

    Economical study of the grey mullet (Mugil cephalus) culture in the Golestan province

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    Striped grey mullet (Mugil cephalus) is a marine fish with high commercial value and widespread distribution. The grey mullet and some other mullets can be found in saltwater, brackish and fershwater habitats at tropical, subtropical and also temporal climates.This species is suitable for aquaculture worldwide due to living in wide ranges of water temperatures and salinities, acceptable growth rate, suitable food conversion ratio, marketability, suitable species for polyculture with shrimps, marine fish and even with freshwater carps. The grey mullet is farming in different countries such as Italy, Northern Africa countries ( Egypt), occupied Palestine, India, Pakistan, Japan, Hong Kong, Taiwan, Vietnam, Indonesia, coastal countries of southern pacific ocean and Hawaii. Ten thousands of fries of this species (average weight and length of 280 mg and 28.3 mm respectively) imported in March 2008 from Egypt. The wild fries colleted from surrounding natural waters of Alexandria. After finishing the quarantine steps, they stocked in four earthern ponds (each with 2500 m2) located at the Gomishan shrimp educational centre at late march in 2008. At the first year of culture the densities were 5000 and 10000 individuals per hectar and each treatment with two replicates. At second years densities changed with 2000 and 2500 ind./hec. and each of traetments divided fishes with average primary weights of 80 and 115 grames. The fries and fish feeding begins in April when the water temperature rise above 18 °C and it cut in fall when the temperature goes under 20°C. They fed twice a day at 8 AM and 2 PM and the amount was 5-7 percents of the fish existent biomass in each ponds. They fed with dry formulated feed made of Mahdaneh Karadj Company (Danso dry feed) both the first and second years of farming. The feed prepared for carps feeding and containded 23±2% crude protein, 10±2% crude lipid, about 7% crude fiber, 15 % ash, 40±2% carbohydrates and with energy content of 4000±200 kcal/kg. After seven months culture period the average weight and length of fish in treatment 5000 ind/hec. were 113.7gr and 21.1cm respectively and in treatment 10000 ind./hec. the average weight and length were 86.6 gr and 19.6 cm respectively. At first year the average survival rate in different treatments was 77 percent. The average FCR in treatments 5000 and 10000 ind./hec. were 3.4 and 3.9 respectively. At second years after six months culture the average weights in pond no. 9 (with primary weight 115 gr and density 2000 ind./hec), pond no. 10 (with primary weight 80 gr and density 2000 ind./hec), pond no. 11 (with primary weight 115 gr and density 2500 ind./hec) and pond no. 12 (with primary weight 80 gr and density 2500 ind./hec) calculated as 476.6, 338.1, 366.5 and 440 gr respectively. The average survival rate and FCR were 93 % and 3.1 respectively. Ponds no. 9 and 11 (fish stocked with primary weight 115 gr in densities both 2000 and 2500 ind./hec) selected as the best economic efficient treatments
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