Table 7. The distances (cm) from spawners and nonspawners to their common center of mass (CCM) and the center of mass of females (FCM) during sea urchin mass spawning.
The data are presented as the median and range (in parentheses). “n” is the number of full tracks of sea urchin movement.
| Interval | Statistical parameter | Strongylocentrotus intermedius | Mesocentrotus nudus | ||||
|---|---|---|---|---|---|---|---|
| From all individuals to CCM | From males to FCM | From nonspawners to FCM | From all individuals to CCM | From males to FCM | From nonspawners to FCM | ||
| n | 131 | 67 | 49 | 165 | 101 | 34 | |
| Control | Median | 17.16 | 20.50 | 23.74 | 19.15 | 25.06 | 30.18 |
| Range | 1.15–36.91 | 4.96–46.89 | 5.92–50.50 | 0.74–58.80 | 3.07–68.16 | 2.58–72.04 | |
| Spawning | Median | 13.53 | 15.75 | 21.62 | 16.02 | 19.35 | 28.43 |
| Range | 0.19–39.16 | 2.93–55.13 | 4.80–54.88 | 0.15–46.71 | 1.82–46.69 | 1.29–101.0 | |
| Control/Spawning comparison | Mann–Whitney U | 12,400,000 | 1,920,000 | 2,222,000 | 21,010,000 | 4,757,000 | 775,386 |
| p | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | =0.0007 | |
| Number of values | 12,746 | 4,962 | 5,220 | 11,106 | 7,699 | 3,058 | |