#class_Hydrozoa__Hydrozoa  coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes
  supertype:  class__clas  (biology) a taxonomic group containing one or more orders
  member of:  phylum_Cnidaria
  member:  hydrozoan__hydroid  colonial coelenterates having the polyp phase dominant
  member:  genus_Hydra  hydras
     member:  hydra  small tubular solitary freshwater hydrozoan polyp
  member:  order_Siphonophora__Siphonophora  marine colonial hydrozoans
     member:  siphonophore  a floating or swimming oceanic colony of polyps often transparent or showily colored
     member:  genus_Nanomia  a genus of Siphonophora
        member:  nanomia  small creatures resembling pieces of fuzzy rope; each with a cluster of swimming bells serving as the head and long elastic tentacles for drawing in prey
     member:  genus_Physalia__Physalia  Portuguese man-of-war
        member:  Portuguese_man-of-war__man-of-war__jellyfish  large siphonophore having a bladderlike float and stinging tentacles
  member:  genus_Sertularia__Sertularia  sessile hydroid that forms feathery colonies
     member:  sertularian  feathery colony of long-branched stems bearing stalkless paired polyps

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