Table 2. Top ten invertebrate taxa based on Index of Relative Dominance (IRD).
IRD = % numerical abundance (number of individuals.m-2) x % frequency of occurrence (freq.). Feed. = feeding groups: 1 = passive suspension feeders, 2 –active suspension feeders, 3 = herbivorous browsers, 4 = carnivores, 5 = omnivores, 6 = deposit feeders.
| Superorder/ Order/Infraorder | Name | Feed. | Num.m-2 (sd) | % num m-2 | % freq. | IRD |
|---|---|---|---|---|---|---|
| Sessilia | Balanus laevis | 2 | 6.07 (7.81) | 12.20 | 77.78 | 949 |
| Echinidea | Loxechinus albus | 3 | 1.33 (1.60) | 2.67 | 94.44 | 252 |
| Lepraliomorpha | Unid encrust. bryozoan | 2 | 1.59 (4.71) | 3.20 | 72.22 | 231 |
| Actiniaria | Bunodactis octoradiata | 1 | 0.95 (1.05) | 1.91 | 83.33 | 159 |
| Aplousobranchia | Didemnum studeri | 2 | 0.74 (1.06) | 1.48 | 88.89 | 132 |
| Aplousobranchia | Sycozoa gaimardi | 2 | 0.59 (1.51) | 1.19 | 83.33 | 100 |
| Aplousobranchia | Polyzoa opuntia | 2 | 0.45 (0.55) | 0.89 | 88.89 | 80 |
| Imparidentia | Gaimardia trapesina | 2 | 1.41 (4.79) | 2.83 | 27.78 | 79 |
| Forcipulatida | Anasterias antarctica | 4 | 0.31 (0.35) | 0.63 | 100.00 | 63 |
| Temnopleuridea | Pseudechinus magellanicus | 3 | 0.35 (0.62) | 0.70 | 88.89 | 62 |