تركيب اسيد هاي آمينه سخت پوستان زئوپلانكتوني تالاب حنا استان اصفهان

The amino acid composition of crustacean zooplanktons in Hanna Wetland, Isfahan Province

Wetlands are among the most productive ecosystems in the world. Zooplanktons are important organisms in wetlands because they are nutritious food for the fish larvae. The nutritional value of zooplankton varies based on species composition, community structure and physicochemical parameters of water in different seasons. This study aimed to measure amino acids composition of freshwater zooplankton in Hanna wetland over four seasons. The sampling was carried out by vertical haul using a plankton net (140 |im, diameter of 25 cm) in the mid-season from summer 1386 till spring 1387. The dominant crustacean zooplanktons in Hanna wetland were Cladocera (3 species of Daphnia genus and each one species from genus Moina, Ceriodaphnia, Bosmina) and Copepoda (including the genus Microcyclops, Acanthocyclops, Allocyclops, Macrocyclops, Metacyciops and Cyclops). Results showed that the average total essential amino acids (EAA) were 28.7 %, 31.0 %, 31.6 % and 34.5 % of total amino acid, while total non-essential amino acids (NEAA) were 71.3%, 69.0 %, 68.4 % and 67.0 % of total amino acid in spring, summer, fall and winter, respectively. Among EAA, arginine 8.9%, 10.7%, 4.1%, and 5.5 %: threonine 6.4%, 4.9%, 6.2%, 7.0 %: thyrosine 4.6%, 4.7%, 4.1%, 3.3 % and methionine 2.4%, 2.2%, 1.6%, 4.1 % of total amino acid respectively in spring, summer, fall and winter were in the highest average levels during study period. Correspondingly, glutamic acid 21.4%, 18.9%, 18.3%, 18.7 %: alanine 16.9%, 15.6%, 14.8%, 12.8 % and aspartic acid 12.3%, 13.0%, 12.1%, 11.3 % were the highest compared to other NEAA in zooplankton samples. The results of this study illustrated that the amino acid composition of the zooplanktons collected from Hanna wetland vary in different seasons. Corresponding author: Keywords: Amino acid, Freshwater zooplankton, Seasonal variability, Hanna wetland, Iran