Figure 3. Temporal dynamics of the locomotion activity of males and females of the sea urchins before and during mass spawning.

(A and B) Strongylocentrotus intermedius. (C and D) Mesocentrotus nudus. The data on the length of sea urchins’ steps and the numbers of spawners were combined into corresponding pools and aligned on the X-axis at the time point coinciding with the beginning of spawning of each individual. Vertical dashed lines denote the boundaries of the control, prespawning and spawning intervals. The black solid line denotes the median step length of sea urchins. Vertical lines indicate the interquartile range (IQR). Blue and red lines indicate the numbers of spawning males and females, respectively (n).