Click the links to browse through the WoRMS marine species taxonomy.
Animalia
  Mollusca
  Porifera
  Platyhelminthes
  Nematoda
  Annelida
  Nemertina
  Arthropoda
  Ctenophora
  Cnidaria
    Anthozoa
    Hydrozoa
      Hydroidolina
        Siphonophorae
        Anthoathecata
          Capitata
          Filifera
            Bougainvilliidae
            Clavidae
            Eudendriidae
            Hydractiniidae
              Clava
              Hydractinia
                Hydractinia aculeata
                Hydractinia allmani
                Hydractinia arctica
                Hydractinia calderi
                Hydractinia carica
                Hydractinia echinata
                Hydractinia fucicola
                Hydractinia fuciola
                Hydractinia humilis
                Hydractinia ingolfi
                Hydractinia monocarpa
                Hydractinia ornata
                Hydractinia serrata
                Hydractinia pruvoti
                Hydractinia tenuissima
                Hydractinia carnea
                    Hydractinia carnea var. mediterranea
                Hydractinia lactea
                Hydractinia areolata
                Hydractinia incerta
                Hydractinia borealis
                Hydractinia solitaria
                Hydractinia inermis
                Hydractinia claviformis
                Hydractinia americana
                Hydractinia polyclina
                Hydractinia valens
                Hydractinia angusta
                Hydractinia clavata
                Hydractinia kaffraria
                Hydractinia vallini
                Hydractinia parvispina
                Hydractinia hooperi
                Hydractinia aggregata
                Hydractinia altispina
                Hydractinia apicata
                Hydractinia arge
                Hydractinia armata
                Hydractinia australis
                Hydractinia bayeri
                Hydractinia bella
                Hydractinia betkensis
                Hydractinia brachyurae
                Hydractinia californica
                Hydractinia canalifera
                Hydractinia carcinicola
                Hydractinia carolinae
                Hydractinia conchicola
                Hydractinia cryptoconcha
                Hydractinia cryptogonia
                Hydractinia cytaciformis
                Hydractinia dendritica
                Hydractinia diogenes
                Hydractinia disjuncta
                Hydractinia dubia
                Hydractinia epiconcha
                Hydractinia epispongia
                Hydractinia exigua
                Hydractinia fallax
                Hydractinia granulata
                Hydractinia hancocki
                Hydractinia hayamaensis
                Hydractinia inabai
                Hydractinia laevispina
                Hydractinia longispina
                Hydractinia mar
                Hydractinia marsupialia
                Hydractinia meteoris
                Hydractinia milleri
                Hydractinia minoi
                Hydractinia misakiensis
                Hydractinia monoon
                Hydractinia multigranosi
                Hydractinia multispina
                Hydractinia multitentaculata
                Hydractinia nassa
                Hydractinia novaezelandiae
                Hydractinia ocellata
                Hydractinia otagoensis
                Hydractinia pacifica
                Hydractinia paucispinata
                Hydractinia piscicola
                Hydractinia polycarpa
                Hydractinia proboscidea
                Hydractinia prolifica
                Hydractinia quadrigemina
                Hydractinia rubricata
                Hydractinia rugosa
                Hydractinia sarsii
                Hydractinia selena
                Hydractinia siphonis
                Hydractinia sodalis
                Hydractinia spinipapillaris
                Hydractinia spiralis
                Hydractinia symbiolongicarpus
                Hydractinia symbiopollicaris
                Hydractinia tenuis
                Hydractinia thatcheri
                Hydractinia uchidai
                Hydractinia yerii
                Hydractinia tournieri
                Hydractinia nagaoensis
                Hydractinia sandrae
                Hydractinia cytaeiformis
                Hydractinia vacuolata
                Hydractinia polytentaculata
                Hydractinia dongshanensis
                Hydractinia uniformis
                Hydractinia antonii
                Hydractinia reticulata
                Hydractinia minima
                Hydractinia gorgonoides
                Hydractinia anechinata
                Hydractinia minuta
                Hydractinia denhami
                Hydractinia reticulata
                Hydractinia reticulata
                Hydractinia rosea
                Hydractinia grisea
                Hydractinia michaelseni
                Hydractinia verdi
                Hydractinia uchidai
                Hydractinia spiralis
                Hydractinia recurvatus
                Hydractinia phialiformis
                Hydractinia munita
                Hydractinia epidocleensis
                Hydractinia alderi
                Hydractinia guangxiensis
                Hydractinia moniliformis
              Hydractomma
              Podocoryna
              Stylactaria
              Stylactis
              Clavactinia
              Cnidostoma
              Hydrocorella
              Janaria
              Fiordlandia
              Parahydractinia
              Hydroconophora
              Echinochorium
              Rhizocline
              Cytaeandra
              Hydrodendrium
              Nuttingia
              Euhydractinia
              Hydronema
              Hydrissa
              Podocorella
              Halorhiza
              Calycidion
            Pandeiidae
            Proboscidactylidae
            Pandeidae
            Rathkeidae
            Trichydridae
            Margelina
            Filifera incertae sedis
            Pandeida
            Calycopsidae
            Cytaeididae
            Niobiidae
            Ptilocodiidae
            Stylasteridae
            Laingiidae
            Protiaridae
            Russelliidae
            Bythotiaridae
            Oceaniidae
            Eucodoniidae
            Australomedusidae
            Balellidae
            Jeanbouilloniidae
            Platystomidae
            Tubiclavoididae
            Cordylophoridae
            Magapiidae
            Axoporidae
            Heterotentaculidae
          Anthoathecata incertae sedis
        Leptothecata
        Laingiomedusae
        Anthomedusae
        Leptomedusae
        Gymnoblastea
        Athecata
        Thecata
        Siphonophora
      Trachylinae
      Hydroida
      Leptolinae
    Cnidaria incertae sedis
    Cubozoa
    Scyphozoa
    Staurozoa
  Sipuncula
  Echiura
  Pogonophora
  Entoprocta
  Tardigrada
  Phoronida
  Brachiopoda
  Echinodermata
  Hemichordata
  Chordata
  Gastrotricha
  Chaetognatha
  Ectoprocta
  Mesozoa
  Rotifera
  Gnathostomulida
  Acanthocephala
  Cycliophora
  Cephalorhyncha
  Placozoa
  Bryozoa
  Myxozoa
  Sipunculida
  Pentastomida
  Nemertini
Plantae
Fungi
Protozoa
Bacteria
Chromista
Archaea
Viruses
Monera