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Thalia democratica

Forskål (1775)

Download a fact sheet for Thalia democratica (PDF 378KB)


Phylum Chordata
Class Thaliacea
Order Salpida
Family Salpidae
Genus Thalia
Species democratica


  • Aggregate form 1.8 - 18.2 mm
  • Solitary form 2.3 - 11.7 mm (without process)

Distinguishing characteristics

Aggregate form


  • Oval
  • Anterior end of body rounded, tapering to a pointed or rounded terminal process
  • Test thick, bluntly pentagonal
  • Atrial opening not central
  • Posterior lateral protuberance on one side only
  • Slight asymmetry
  • Variable number of tubular process from mantle to test


  • 5 continuous body muscles
  • M1-M3 and M4-M5 fused mid dorsally for short distance
  • The two groups of muscle bands are separate dorsally
  • Muscle structure similar to other Thalia aggregates, species differentiated by shape of body and projections


  • More compact than in solitary form
  • Endostyle confined to anterior half of body
  • Nucleus has posterior projection (may not be visible)

Solitary form


  • Smooth test
  • Lateral projections simple and not bifurcated
  • All test projections are echinate


  • 5 body muscles in complete rings
  • M5 may be narrowly interrupted ventrally
  • M1-M3 and M4-M5 fused mid-dorsally over short distance
  • Muscle structure similar to other Thalia solitarys, T. democratica differentiated by non bifurcated lateral projections


  • Stomach partly extends into middle posterior projection
  • Distribution
  • Cosmopolitan, eurythermic species from warmer waters. Globally between 60°N - 40°S



  • Godeaux, J. E. A. (1998). The relationships and systematics of the Thaliacea, with keys for identification.
  • Thompson, H. (1948). Pelagic tunicates of Australia, CSIRO, Melbourne, Australia.
  • Van Couwelaar, M. (2003). Zooplankton and micronekton of the North Sea. Expert Center for Taxonomic Identification, Amsterdam.