University of Tasmania, Australia

UTAS Home | UTAS Staff | UTAS Contacts


UTAS Home > IMAS Home > Image Key > Copepoda > Harpacticoida >  Microsetella norvegica

Microsetella norvegica

Boeck (1865)

Download a fact sheet for Microsetella norvegica (PDF 455KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Harpacticoida
Family Ectinosomatidae
Genus Microsetella
Species norvegica


  • Female: 0.35 - 0.53mm
  • Male: 0.33 - 0.42 mm

Distinguishing characteristics

  • Body slender & laterally compressed
  • Urosome is as wide as metasome
  • Caudal rami setae nearly as long as body and divergent


  • Smaller than female but similar shape
  • A1 is geniculate
  • Caudal rami a little wider than long


  • Short rostrum turned downwards
  • P5 2 inner setae of different length
  • Traverse rows of minute spinules on urosome
  • Caudal rami as long as wide and divergent
  • Longest caudal rami setae nearly as long as body, second is ¾ as long as body

Note - similar to M. rosea:

  • Check size, if over 0.8mm it is likely M. rosea
  • Length of caudal rami setae, if nearly twice as long as body then it is M. rosea, if shorter than it could be either species (setae could be broken)
  • M. rosea has spinules on metasome and urosome, M. norvegica has spinules on urosome
  • M. norvegica caudal rami slightly more divergent than M. rosea
  • M. rosea may be coloured pink


  • Epipelagic-bathypelagic
  • Cosmopolitan, oceanic and coastal
  • Found in tropical and subtropical regions of Australia
  • World distribution: widespread in all oceans


  • Widely distributed marine planktonic copepod
  • Biology is poorly known
  • Can be one of the numerically dominant species in coastal waters
  • In oligotrophic waters this species is known to associate with marine snow aggregates, where attached microbial communities provide a nutrition source
  • In eutrophic waters, where there are abundant food particles in water column, such associations are not observed (e.g. Inland Sea of Japan)
  • Long caudal setae might assist in swimming by slowing sinking rate
  • Will often aggregate in regions with relatively high turbulence, thought to also assist with swimming
  • Stenohaline by nature, preferring a narrow range of salinities
  • Females carry a single egg sac and can breed more than once
  • Time from egg laying to moulting to adulthood is temperature dependent (at 20º C duration was 31.9 days and at 27º C, 14.3 days)
  • Herbivorous


  • Conway DVP, 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, Vol Occasional Publications No. 15. Marine Biological Association of the United Kingdom.
  • Diaz & Evans (1983)
  • Green & Dagg (1997)
  • Ohtsuka et al (1993)
  • Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2009. Diversity and Geographic Distribution of Marine Planktonic Copepods. Available at
  • Uye et al (2002)