| Table 6. Ecological characteristics of Group I and Group III type species. | |
| Group I | Group III |
| 1. Opportunistic Species | 1. Equilibrium Species |
| a. Many reproductions per year | a. Few reproductions per year |
| b. High recruitment | b. Low recruitment |
| c. Rapid development | c. Slow development |
| d. Early colonizers | d. Late colonizers |
| e. High death rate | e. Low death rate |
| 2. Small | 2. Large |
| 3. Sedentary | 3. Mobile |
| 4. Deposit Feeders | 4. Deposit and Suspension Feeders |
| (mostly surface feeders) | |
| 5. Brood Protection; | 5. No Brood Protection |
| Lecithotrophic Larvae | Planktotrophic Larvae |
| *Table adapted from McCall (1977). | |