The influence of hydrogen ion concentration on growth and development of Xenopus laevis larvae

Optimal pH values and variable H+ concentrations in water for the development and growth of larvae in Xenopus laevis Daudin were revealed. Slightly alkaline reaction is the most favorable for developing the larvae. Fluctuations of pH within a range of 1 accelerate the development and rate of the linear and weight growth of test individuals by 15 % and 40 %, respectively. Under unstable pH, mortality of larvae is reduced, variation of sizes in the year's brood becomes higher, and the duration of metamorphosis decreases. Periodical pH deviations from its constant optimum within a range of tolerance favor the development of larvae to a greater extent than any constant pH values.