Survey of some properties of population dynamic of Capoeta trutta in Alvand River in Kermanshah province (IR .Iran

In this study some biological and ecological (i.e. Age, growth and Reproduction) characteristics of Capoeta trutta in Alvand River in Kermanshah provience were studied from August 2008 to June 2009. During the study 225 specimens were caught by using cast net and gillnet from Alvand totally, six totally, six age group in this River identified. sex ratio of alvand population was 1.27♂: 1♀. In this study it was revealed that in Age, length and weight frequencies female was longer and heavier than males. Mean GSI of fish in Alvand River was 1.71 ± 0.14 also,mean condition factor of fishes in Alvand River was 1.13 ± 0.007,There was no significant differences between males and female fishes (p> 0.05). mean egg diameter was 0.8  0.06 mm. Absolute fecundity was 15233 ± 11058 eggs.