Microsetella norvegica
Boeck (1865)
Download a fact sheet for Microsetella norvegica (PDF 455KB)
Taxonomy
| Phylum | Arthropoda |
| Subphylum | Crustacea |
| Class | Maxillopoda |
| Subclass | Copepoda |
| Order | Harpacticoida |
| Family | Ectinosomatidae |
| Genus | Microsetella |
| Species | norvegica |
Size
- 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
Male
- Smaller than female but similar shape
- A1 is geniculate
- Caudal rami a little wider than long
Female
- 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
Distribution
- Epipelagic-bathypelagic
- Cosmopolitan, oceanic and coastal
- Found in tropical and subtropical regions of Australia
- World distribution: widespread in all oceans
Ecology
- 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
References
- 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 http://copepodes.obs-banyuls.fr/en@
- Uye et al (2002)