Annelida · segmented worms

Giant tube worm

Riftia pachyptila

Siboglinidae · beard worms & vent wormsIUCN: Not evaluated
Giant tube worm
Photo: Ifremer · CC BY 4.0 · Wikimedia Commons · resized

A red-plumed worm living at hydrothermal vents, with no mouth or gut.

Fun factBacteria inside it make food from hydrogen sulfide.

Waters
Eastern Pacific
Depth zone
Hydrothermal vents
Diet
Symbiotic chemosynthetic bacteria
Size
Up to 3 m

Classification

Annelida › Siboglinidae

  1. Kingdom Animalia animals
    • Many-celled organisms that eat other living things for energy (heterotrophs)
    • Cells have no cell walls
    • Most can move at some stage of life
  2. Clade Bilateria bilateral animals
    • Body has a left and right side that mirror each other (bilateral symmetry)
    • Head end with concentrated nerves; three tissue layers
    • Includes about 99% of all living animal species
  3. Clade Protostomia protostomes
    • In the embryo, the first opening usually becomes the mouth
    • Main nerve cord runs along the belly (ventral)
    • Includes mollusks, worms, and arthropods
  4. Clade Spiralia mollusks, worms & kin
    • Embryos usually divide in a spiral pattern (spiral cleavage)
    • Many have a swimming larva with a band of cilia (trochophore)
    • Includes mollusks and segmented worms
  5. Phylum Annelida segmented worms
    • Segmented worms: body divided into repeated ring-like segments
    • Bristles (chaetae) help many grip and move
    • Includes bristle worms, earthworms, and leeches
  6. Clade Sedentaria tube-dwelling worms
    • Tube-dwelling and burrowing worms
    • Often have a crown of feeding tentacles or reduced side flaps
  7. Family Siboglinidae beard worms & vent worms
    • Beard and vent worms with no mouth or gut as adults
    • Get food from symbiotic bacteria inside their bodies
  8. Genus Riftia
    • Species in the same genus are very close relatives and often look alike.
  9. Species Riftia pachyptila Giant tube worm

Closest relatives in the guide