Tian Shan Scale-Scaled Osman - Diptychus gymnogaster
This species is the most interesting of the six species of the Osman genus from the carp family found in the water bodies of Kyrgyzstan.
The local population refers to it as mountain or river trout. This is incorrect because trout and osman belong not only to different genera but also to different families.
The Tian Shan Scale-Scaled Osman differs from other osmans in that its body is covered with scales that cover the entire back and sides; it is relatively large, measuring 50 centimeters or more and weighing over one kilogram.
The original coloration of this fish allows it to be easily distinguished from other species of this genus: the back and sides are dark, olive-green, the belly is light yellow with an orange border. Clear dark spots are scattered on the head, back, and sides. Similar but smaller spots adorn all fins and the lower part of the throat.
Like all osmans, the Tian Shan osman is a long-lived species, with individuals found to be 13 years old or more.
It was most numerous in Lake Issyk-Kul, where it served as a target for fishing. Currently, efforts by the government and international projects are aimed at restoring the osman population in Lake Issyk-Kul.
As with marinka, usach, and khramuli, the roe and internal organs of the osman are toxic.
Fish