The survival of amphibian embryos after continuous ultrasonic treatment

The effect of continuous ultrasonic treatment on the development of early embryos of common frog Rana temporaria was studied. Intact embryos at the blastula stage were exposed to ultrasound of various frequencies (0.88 and 2.64 MHz) and intensities (0.05 to 1.0 W/cm²) for various periods (1 to 15 min). The increase in ultrasound intensity to 0.7–1.0 W/cm² and exposure time to 5–15 min resulted in nearly complete mortality. Development of the embryos exposed to ultrasound of medium intensity (0.2–0.7 W/cm²) for 1–5 min was virtually similar to the control. Treatment at a frequency of 2.64 MHz and intensity of 0.05–0.7 W/cm² for 1–5 min had no effect on the development of amphibian embryos and their survival rate. The increase in intensity of the ultrasound of this frequency to 1 W/cm² and the exposure time to 5 min decreased the number of normally developing embryos by 35%.