M.R Mohaghegh - Jihad Keshavarzi Department, Iran
T Valinasab - Jihad Keshavarzi Department, Iran

The Kutum fish (Rutilus frisii kutum), a member of Cyprinid family, mainly found inthe coastal area from Azerbaijan to Turkmenistan and considered to be a valuablecommercial fish of the Caspian Sea. The aim of this study was to determine theOtolith shape of the Caspian white fish and the possibility of determining the age ofthe fish using the ear stone cutting and different length and weight relationships ofear stones. In this study, two groups of the wild (Caspian Sea) were collected forfurther ageing using otolith (sagitta). The samples were transferred to the laboratory,the meristic and morphometric factors were measured to the nearest 1 mm and alsowere weighed to the nearest 0.1 g. The sagita were removed by cutting the head andthen prepared to determine the age. The results showed that the fishes had a range of1 to 4 years old. The review sections obtained from the biggest ear stone called Sagita,fish age 1+ to 4+ , respectively. There are a pair of relatively large and clear otolith inKutum. A longitudinal section along with the interior and exterior surfaces are almostoval and in most cases has sharp front end and the rear end are bulged. Rostrum islocated on the long axis of the otolith tip and anti-rostrum on the short axis. Arelationship between length and weight of fish length, weight and age of the marineenvironment were obtained. The highest correlation between fish length and otolithis r2 = 0.892 and the relationship between total length and body weight wasW = 0.000005 TL 3.

Kutum Fish, Otolith, Caspian Sea