LAUSR

Abstract The determination of the carnosine level in fish muscle tissues is helpful for the purposes of general biology and comparative muscle physiology of various fish species; it may be also useful for estimation of the nutritional value of fish products. The mass-spectrometric method of the determination of carnosine in muscle tissues has been improved and tested in this work. The carnosine levels in the muscles of the Russian sturgeon, Siberian sturgeon, sterlet, hybrid of sterlet and kaluga, hybrid of Siberian sturgeon and kaluga have been determined for the first time with this method. The starlet-and-kaluga hybrid, regardless of sex, contains 3.33 times more carnosine than the sterlet ( p < 0.01). The female hybrid of Siberian sturgeon and kaluga contains 1.50 times less carnosine than the female Siberian sturgeon ( p < 0.1). Since carnosine consumption is important for carnosine biosynthesis in human muscles, the hybridization of sterlet with kaluga is more efficient in terms of nutrition value than pure sterlet breeding, and the hybridization of Siberian sturgeon with kaluga is less effective than sturgeon breeding.