اثر تغييرات فصلي بر تركيب اسيدهاي چرب سخت پوستان زئو پلانكتوني تالاب حنا

چكيده انگليسي :

The effect of seasonal variability on fatty acids composition of crustacean zooplankton in Hanna wetland Sara Kolivand E mail kolivandsara@yahoo com Mar 11 2009 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Language Degree M sc Farsi O Farhadian Assist Prof Supervisor omfarhad@cc iut ac ir E Ebrahimi Assist Prof Supervisor e ebrahimi@cc iut ac ir Abstract Zooplanktons is very important group of living organisms as they are the basis for food web in aquatic ecosystems Among zooplanktons cladocerans and copepods play a key role in the freshwater food chains They transfer energy from microalgae to the higher trophic levels by being eaten as a food through various aquatic organisms These creatures contain a valuable source of protein amino acids lipid fatty acids vitamins and enzymes It has been demonstrated that several environmental factors such as temperature depth salinity geographical location season food availability and starvation could affect the fatty acids profile of zooplankton In addition it should be noted that the nutritional values particularly fatty acids content of mixed zooplankton strongly influences by the proportion of different zooplankton species in collected sample Although there are many report on fatty acid composition of different zooplankton groups from separated geographical location information on fatty acid composition of mixed zooplankton from Iranian aquatic ecosystems are scarce The purpose of this study was to provide basic information on fatty acid composition of mixed freshwater zooplankton from Hanna wetland situated at Eastern part of Isfahan province Iran during different seasons Furthermore we investigated the effects of water quality and zooplankton community structure mainly proportion of the individual constituents on fatty acid composition In order to study the suitability of freshwater zooplankton of Hanna wetland Isfahan Iran for aquaculture purposes determination of fatty acid composition of mixed zooplankton samples collected from the lake was carried out at in the middle of each season for a one year period from May 2007 to February 2008 The samples were collected by vertical haul using plankton net 140 m The total density of cladocerans was the highest in spring 77 19 including three species of Daphnia longispina D dubia and D pulex The identified copepod species were all belong to cyclopoids with the highest density observed in fall 98 46 Fatty acid composition significantly P 0 05 varied in relation to the seasonal changes of zooplankton community The content of saturated fatty acids SFA mono unsaturated fatty acids MUFA and polyunsaturated fatty acids PUFA ranged from 27 79 32 09 39 18 43 03 13 61 25 36 of total fatty acids respectively Results showed that ratios of n 3 n 6 were 0 70 1 2 53 1 1 89 1 and 1 73 1 in spring summer fall and winter respectively More suitable n 3 n 6 ratio was observed in mixed zooplankton of Hanna wetland during summer The docosahexenoic acid DHA 22 6n 3 to eicosapentaenoic acid EPA 20 5n 3 ratios of Hanna zooplankton ranged from 0 18 1 to 0 21 1 indicating that enrichment of these zooplankton is needed if they are to be used in fish larvae culture Keywords Fatty acid Freshwater zooplankton Seasonal variability Hanna wetland Iran pdfMachine A pdf writer that produces quality PDF files with ease Produce quality PDF files in seconds and preserve the integrity of your original documents Compatible across nearly all Windows platforms if you can print from a windows application you can use pdfMachine created with pdfFactory Pro trial versionGet yours now PDF www pdffactory com

كوليوند، سارا

اثر تغييرات فصلي بر تركيب اسيدهاي چرب سخت پوستان زئو پلانكتوني تالاب حنا

اكوسيستم آبي