Size and structure of populations of the march frog Pelophylax ridibundus Pal. (Amphibia, Anura) in waters, contaminated by karbamide insecticides

In populations of Marsh Frog in waters polluted by carbamide insecticides (2MPC) in comparison with those from clear waters are recorded: lower number of individuals (from 1.2 to 1.8 times in different seasons); higher number of striata morph (from 1.5 to 3.3 time in different seasons); higher number of females (from 1.6 to 2.1 in different seasons) and a spring dominance of immature individuals (two times of mature individuals).