Table 3.
Monthly semen characteristics for in situ sand tiger sharks Carcharias taurus.
| Month | n | Mean ± SE | Median | Range | Group* |
|---|---|---|---|---|---|
| Sperm concentration (106/ml) | |||||
| April | 17 | 13.15 ± 3.06 | 10.15 | 0.08–39.5 | a |
| June | 7 | 196.29 ± 65.45 | 119 | 28–466 | ab |
| July | 6 | 490.5 ± 214.19 | 350.5 | 117–1540 | b |
| Volume (ml) | |||||
| April | 17 | 218.8 ± 41.6 | 120 | 50–580 | a |
| June | 7 | 103.2 ± 30.8 | 130 | 7.5–200 | ab |
| July | 6 | 12.6 ± 3.0 | 12 | 3.5–25 | b |
| Morphology (%) | |||||
| April | 15 | 96 ± 1 | 98 | 87–100 | a |
| June | 7 | 90 ± 6 | 96 | 58–100 | a |
| July | 6 | 64 ± 10 | 72.5 | 32–95 | b |
| Plasma membrane integrity (%) | |||||
| April | 12 | 67.8 ± 8.0 | 77.5 | 10–95 | a |
| June | 7 | 53.7 ± 10.4 | 45 | 22.8–85 | ab |
| July | 6 | 22.7 ± 5.4 | 21.7 | 5–45 | b |
| Total motility (%) | |||||
| April | 16 | 61.9 ± 7.7 | 70.25 | 10–95 | a |
| June | 7 | 45.2 ± 10.3 | 33.1 | 15–80 | ab |
| July | 6 | 14.6 ± 2.6 | 16.25 | 5–20 | b |
| Progressive motility (%) | |||||
| April | 16 | 19.8 ± 3.9 | 20 | 0–50 | a |
| June | 7 | 14.4 ± 4.8 | 9.3 | 5–35 | a |
| July | 6 | 0.8 ± 0.4 | 0.5 | 0–2.5 | b |
*Letters indicate group membership from Kruskal–Wallis test and Dunn post-hoc pairwise comparisons with Benjamini–Hochberg adjusted P-values. Groups that share a letter are not different using a significance threshold of P < 0.05.