DETERMINATION OF NUTRIENT VALUES OF THE BIVALVE ANODONTA CYGNEA IN SELKEH AREA OF THE ANZALI LAGOON DURING AUTUMN AND SPRING

Anzali Lagoon is one of the most important aquatic ecosystems of Iran which was registered as a Ramsar Convention site in 1999. This valuable ecosystem is located in the south west shores of the Caspian Sea, in GuilanProvince. We randomly collected 30 and 20 samples of the bivalve Anodonta cygnea in autumn 2004 and spring 2005 respectively. The Selkeh area was chosen for the sampling because of its availability during autumn. The area receives water from the southern part of the lagoon basin. Nutrient content of the soft tissue of the bivalve was measured. Live sampled bivalves were transferred to laboratory and their length, width, height; total body weight and wet weight of the internal soft part were measured. Moisture, ash, protein, T.V.N, lipid and amino acid contents in soft tissue were also determined. Moisture content in spring and autumn samples were 84.84% and 83.6%, respectively. Ash content in autumn samples was higher than spring samples, being 4% and 2.32%, respectively. Assessment showed protein content in the autumn samples to be 12% while in spring samples this was 10.5%. T.V.N content in autumn and spring samples were 0.031 and 0.003% respectively. Measurements showed that autumn bivalves had 4% lipid content whereas this value in spring samples was 3%. We found Sixteen amino acids, including seven essential ones in the samples.