Study of age and growth of Crucian carp (Carassius auratus gibelio) in Siyahrood River of Qaemshahr, Mazandaran Province of Iran

Crucian carp is a non-indigenous species in Iranian waters.The fish resistance to lack of oxygen and food, gynogenesis system, rapid reproduction and early maturation are among the factors that affect fish increasing strongly in biological environments. The study samples were collected from the Siyahrood River of Qaemshahr by Electroshocker. A total of 19 crucian carps were divided into 4 age groups 0+, 1+, 2+, 3+ for the female and three groups 0+, 1+, 2+ for a male. The average length of each of the age groups of male 0+, 1+ and 2+ respectively 94.26, 94.62 and 123.09 and age group of 0+, 1+, 2+, 3+ 106.7, 111.26, 136.96, 217.16 respectively. The mean of male weight in the age groups 0+, 1+, 2+ was 12.99, 11.5 and 31.57, and the mean of female weight in age groups 0+, 1+,2+, 3+ were calculated 14.1, 22.19, 41.26 and 182.5 respectively. Due to the growing number of physical factors in female (3.19) and male (3.46) is the positive allometric growth for both sexes. The condition factor for expressing the status or obesity of fish in the age groups of 0+, 1+, and 2+ was 0.17, 0.16 and 0.18, respectively, and for female sexes, in age groups, 0+, 1+, 2+, 3+ were calculated to 0.61, 0.58, 0.62 and 0.45 respectively. The GIS index for both males and females in different age groups was calculated to 1.8, 2.4, 6.72 and 13.91, 12.3, 9.68, and 10 respectively.

Keywords:

Crucian carp , Age , Growth , Condition factors , Siyahrood River