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UTAS Home > IMAS Home > Image Key > Chaetognatha >  Seratosagitta tasmanica

Seratosagitta tasmanica

Thompson (1947)

Download a fact sheet for Serratosagitta tasmanica (PDF 294KB)


Phylum Chaetognatha
Class Sagittoidea
Order Aphragmophora
Family Sagittidae
Genus Serratosagitta
Species tasmanica


  • Maximum body length 30 mm, tail 20-30% of body

Distinguishing characteristics 

  • Serrated hooks 6-9
  • Anterior teeth 6-9
  • Posterior teeth 9-15
  • Body needle-like and firm, opaque
  • Transverse musculature absent
  • Head large
  • Fin bridge absent, but fins close together
  • Anterior fins of medium length, reaching to posterior end of ventral ganglion, partially rayed, rounded
  • Posterior fins long, partially rayed, rounded
  • Collarette absent or very small
  • Gut diverticula absent
  • Small eyes with T-shaped pigment spot
  • Seminal vesicles with elaborate knob with numerous protuberances, between fins, nearly touching both when mature
  • Ovaries long, may reach anterior end of ventral ganglion
  • Ova small
  • Adhesive papillae and adhesive organs absent
  • Apical glands absent





  • Conway, D. V. P., White, R.G., Hugues-Dit-Ciles, J., Gallienne, C.P. and Robins, D.B. (2003). Guide to the coastal and surface zooplankton of the south-western Indian Ocean, Marine Biological Association of the United Kingdom
  • Marine Species Identification Portal,