Noctilucales

Noctilucales
File:Noctiluca scintillans unica.jpg
Scientific classification
Domain:	Eukaryota
(unranked):	Sar
Superphylum:	Alveolata
Phylum:	Dinoflagellata
Class:	Noctiluciphyceae Fensome et al., 1993
Order:	Noctilucales Haeckel, 1894
Families
Kofodiniaceae Leptodiscaceae Noctilucaceae

The Noctilucales are a peculiar order of marine dinoflagellates.

Characteristics

They differ from most others in that the mature cell is diploid and its nucleus does not show a dinokaryotic organization; also they show gametic meiosis. These cells are very large, from 1 to 2 millimetres in diameter, and are filled with large buoyant vacuoles. Some may contain symbiotic green algae, but there are no chloroplasts. Instead, they feed on other plankton, and there is usually a special tentacle involved in ingestion.

Noctilucales reproduce mainly by fission, but sexual reproduction also occurs. Each cell produces numerous gametes, which resemble more typical athecate dinoflagellates and have the dinokaryotic nuclei. Evidence suggests that they diverged from most other dinoflagellates early on, and they are generally placed in their own class.

Examples

The most common species is Noctiluca scintillans, also called N. miliaris. It can be bioluminescent when disturbed, as are various other dinoflagellates, and large blooms can sometimes be seen as flickering lights on the ocean, known as the milky seas effect.

Another example is Spatulodinium pseudonoctiluca.

External links

• Noctiluca scintillans — Guide to the Marine Zooplankton of south eastern Australia, Tasmanian Aquaculture & Fisheries Institute