Key: Step 1. Start
Step 2. Short introduction
Step 3. Chaetognatha
Step 14. Cnidaria
Step 141. Crustacea
Step 392. Ctenophora
Step 394. Mollusca
Step 452. Polychaeta
Step 454. Tunicata
Step 477
Step 479. Larval stages
Step 489. Taxon unknown
Decision path