Figure 8
SH values in specimens of the two morphotypes plotted against their whorls numbers (logarithmic scale). The samples are from the Tenis Lake. Omsk Region (see Additional file 1: Table S1). The regression equations and regression lines are provided. The slopes of the two lines are significantly different (p = 0.0001). Enlarged photographs of shell spires of fragilis and stagnalis show difference in their coiling rates.