Scute structure reveals sex of juvenile and young sturgeon in caviar aquaculture technology

Sturgeons are valued as specialty black caviar, which is very expensive. Only females are used in the technology of caviar aquaculture. Universal method of sex determination has not yet been developed. Most of known methods are not sufficiently accurate, or used at a relatively late age, or difficult to use. Perfect early determination of sex is considered to be impossible. Because of the dark color of most sturgeon, important morphological differences, which fish of almost all ages have, were overlooked. We first found that the scute structure of Sterlet and Siberian sturgeon depends on the sex, such a pattern is typical for sturgeon of all ages. We found that sex determination is possible at very early stages. Dependencies found with the help of machine learning method open a possibility for creation of sex determination equipment using the artificial intelligence. Our results open a perspective for creation of the sex determination methods for other 23 sturgeon species, which can increase the efficiency of caviar aquaculture and sturgeon restoration in natural waters.