ИСТИНА

The survival and developmental rate in early ontogenesis at two populations of a common toad (Bufo bufo) area were compared in experimental condition. These populations were taken from various reservoirs of the Moscow region. The first population is localization in area of Zvenigorodskoj of a biological research station of MSU in 12 km from g. Zvenigorod on right bank of Moscow river. The spawning is carried out in a small Sterlyaziy pond (XXX square m.) of an artificial origin. The second population is localization in area of lake Glubokoe in 20 km from g. Zvenigorod. The lake Glubokoe, in which the spawning is carried out, a glacial origin, its area nearby 0,5 square km with pure, transparent water. In the course of long-term investigations in first population of common toad, it was shown, that in the in early ontogenesis of common toad the too strategies of survival on reaction to density exist (Dmitrieva 2003, 2007). In some spawns the relationship between survival rate and egg density evaluated at the hatchling stage has a shape of monotone curve. In other spawns, the relationship between survival rate and egg density has a shape of a curve with two maximums (non-monotone). It is possible to observe the second maximum of embryonic survival rate existing at the high values of density. At spawns from the second population such picture is not observed. The correlation between mortality of hatchling and egg density in the first population above (r =-0,35), than in the second (r =-0,28). The developmental rate in two these populations do not differ. The received results it is possible to explain that in the second populations (lake) the condition of embryos development more favorable, than in the first populations (pond). In the lake water is more purer, there are more suitable places for spawning and more space for development of eggs. In the pond of a condition of development closer for development of embryos, therefore the additional mechanism of a survival here was generated at the raised density.