Early development of olfactory and taste organs in Caspian Kutum, Rutilus kutum, Kamensky, 1901

This study was conducted to assess the ontogeny of the olfactory and taste organs in Caspian Kutum, Rutilus kutum</em>, from hatching up to 23 days post hatching (DPH). So that, the larvae were randomly sampled daily from 1 to 23 DPH. After fixation in buffered formalin and glutaraldehyde, the histological sections were prepared, then the olfactory and taste organs were examined using light and electron microscopies. The results exhibited complete nasal formation and the increasing number and size of the taste buds in the oral cavity, lips, as well as around the mouth on 5 DPH. In addition, on 12 DPH, further development of the olfactory cells and taste buds were observed. This increasing trend was continued until 16 DPH. According to the results, the olfactory organ was completed earlier than the taste one, and the number of taste buds was higher on the upper lip. The maturation of the taste buds was observed at 20 DPH. The results revealed that the development of chemical sense organs is closely related to the development of Caspian Kutum’s gastrointestinal system.