| dc.description.abstract | Research on the influence of hydro-biological properties of reservoirs on the development of tadpoles of Rana
temporaria L. was carried out in five natural, low-lying reservoirs in a small area near Kraków. Each reservoir
represented different hydro-biological properties. The following physico-chemical properties of the water in each
reservoir were during the development of tadpoles: temperature, pH value, alkalinity, the amount of oxygen
dissolved O[2] mg/l, the percentage of saturation with oxygen.
During the period of development of larvae in April, May, June, July, 1967 altogether 1587 tadpoles of Rana
temporaria L. were caught in the reservoirs. Their stage of development was defined and the complete body length
measured. The average length of the tadpoles at the stage of maximum development ranged from 29-41 mm, the maximum
length being 32-44 mm. The average length of newly transformed specimens was within 10-13 mm.
In each of the reservoirs the course of the development of tadpoles including the time of metamorphosis and the
average size of tadpoles at the stage of maximum development and the newly transformed ones were different. Factors
such as the ranging and level of the water temperature during the life of the tadpoles as well as the oxygen
conditions in a given reservoir remain essentially connected with the length of the development and the size of the
tadpoles. pH value of the water within pH 6,1-6,4 has no adverse effect on the course of the development end the
size of the tadpoles.
The occurrence of tadpoles of Rana temporaria L. in all of the reservoirs, including those with extremely
unfavourable hydro-biological conditions and in which exclusively the tadpoles of this frog were present, shows
them to be eurytopic organisms. | en_EN |
