Taxonomic Hierarchy 
      
        
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 |   | Kingdom | Animalia 
 – Animal, animaux, animals | 
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|   |    Phylum | Cnidaria Hatschek, 1888
 – cnidarians, coelenterates, cnidaires, coelentérés, água viva, anêmona, caravela, cnidario, coral, hidra | 
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|   |       Subphylum | Medusozoa 
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|   |          Class | Hydrozoa Owen, 1843
 – hydralike animals, hydroids, hydrozoans, hydraires, hydrozoaires, água viva, hidra, hidrozoa, hidrozoário, pólipo | 
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|   |             Subclass | Hydroidolina 
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|   |                Order | Leptothecatae 
 – thecate hydroids, hydromedusae | 
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|   |                   Family | Campanulariidae 
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|   |                      Genus | Obelia Péron and Lesueur, 1810
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|   |                         Species | Obelia dichotoma (Linnaeus, 1758) – sea thread hydroid, sea thread hydroid | 
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