Bio-ecological characteristics of swan mussel, Anodonta cygnea, Linnaeus, 1758 in the Lake Çıldır

SUMMARY Bio-Ecological Characteristics of Swan Mussel, Anodonta cygnea Linneaus 1758 in the Lake Çıldır. Swan mussel is an endemic species of Lake Çıldır, located in the east of Turkey Population structure, growth rates, condition index, biochemical composition of somatic tissues and larval (glochidium) development of the species have been studied. 1227 specimens of A. cygnea were sampled from the Lake by the Sucuba divers from May 2001 to October 2001. Relevant enviromental variables, namely temperature, electrical conductivity, pH, oxygen and chlorophyll-a, were also followed. A. cygnea samples consisted of individuals with size range of 45-145 mm and mean shell length of 104.2 ± 0.52 mm, and live weight of 94.8 + 1.42 g. The relationship between shell length and live weight was estimated as W = 0,0001 *L2'88 (r=0.96). Condition index values exhibited clear monthlly variations: reaching maximum value in July C, =16.28±1.56, minumum value in October d=13.92±0.55. The relationship between the dry meat weight and the length DMW=0.000003*L299 (r=0.95) Number of larvae produced by 99.3±0.23 mm mean shell length were 1 14999±955 and the relationship between these parameters was found as N=43.696*L' 68 (r=0.42). Biochemical composition values (dry meat, water, ash, crude protein and crude lipid) of tissue show montly variations. Mean crude protein and lipid contents of A. cygnea were 41.66% and 6.39 % respectivly. Reproductive period was controlled from May 2001 to July 2002. Duration of the gravity continued from the end of the July to nex year June. Key words: Swan mussel, Lake Çıldır, Anodonta cygnea, Glochidium, Population Parameters VII