Effect of pH and illumination oscillations on growth rate and development of Rana ridibuncla larvae

摘要

The most suitable variable regimes of pH and illumination for the growth and development of Rana ridibunda larvae were found. The frog larva growth increased and variation of its size decreased in pH of water 7.0-8.0 and illumination 600-4200 lx. Under these conditions, the rate of developing the larvae was by 10 percent higher. This year brood developed under optimal regimes was of larger size; their linear and mass characteristics were o less variable. The results obtained show that the changes ofpH and illumination within definite ranges are more favorable for Rana ridibunda tadpoles than the environment with constant characteristics of these parameters.