Table 4 Results of t-tests evaluating the effect of rock type on mean byssal tread counts, mean mussel attachment strength, and the mean proportion of four thread failure locations per individual mussel
| Variable | df | t | P |
|---|---|---|---|
| Byssal thread countsa | 28 | 4.28 | < 0.01 |
| Attachment strength | 64 | 0.90 | 0.37 |
| Thread failure (%) | 28 | 0.49 | 0.63 |
| Plaque failure (%)a | 28 | 3.22 | < 0.01 |
| Rock failure (%) | 28 | 2.99 | < 0.01 |
| Loose particle failure (%) | 28 | 1.97 | 0.06 |