Hydrozoa

Taxonavigation Kingdom: Animalia Sub Kingdom: Eumetazoa Super Phylum: Radiata Phylum: Cnidaria Class: Hydrozoa Order: Filifera - Milleporina - Siphonophora - Stylasterina

Introduction

Hydroids or hydrozoans are organisms contained with the class Hydrozoa, within the phylum Cnidaria. They actually make up about 2/3rds of the total number of species within the phylum. They can become pests within marine aquarium because of the rapid growth and strong stings of some of the species. Fire corals, which is a hydroid of the Millepora genus, are commonly seen for sale in stores. They will also be found as hitchhikers on liverock or corals purchased.

Classification

• Filifera -
• Milleporina -
• Siphonophora -
• Stylasterina -

Gallery

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  Myrionema sp.
  Brown Hydroid
  Order: Filifera
• 
  Physalia physalis
  Bluebottle
  Order: Siphonophora
• 
  Distichopora sp.
  Purple Lace Coral
  Order: Stylasterina

Miscellaneous Images

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  Hydroid growing across glass, right to left, with polyps visible.
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Resources

• Hydroids by Ronald Shimek - Aquarium.Net
• A creature from outer space or a hydroid for Liberace's piano? by Julian Sprung - Advanced Aquarist's Online Magazine
• wikipedia:Hydroid