Noctiluca scintillans
Noctiluca scintillans, commonly known as the Sea Sparkle, and also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...

 that exhibits bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...

. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelle
In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....

s, or “microsources”, located throughout the cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

 of this single-celled protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...

. Nonluminescent populations within the genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Noctiluca lack these microsources.


N. scintillans is a heterotrophic (non-photosynthetic) organism that engulfs its food (phagotrophic) which primarily consists of plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

, including diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...

s and other dinoflagellates, as well as fish eggs and bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

. Diatoms are often found in the vacuole
A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain...

s (internal membrane-bound storage compartments) within these single-celled creatures. These green non-feeding symbioses can grow photoautotrophically for generations. The diatom Thalassiosira sp. has been noted in the literature as a favored food source of these organisms.


N. scintillans can be found widely distributed throughout the world, often along the coast, in estuary, and shallow areas of the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

 that receive plenty of light which promotes the growth of the phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...

 that make up a large portion of N. scintillans’s diet.


The size of the single-celled N. scintillans ranges from 200 to 2,000 µm in diameter, assuming the generally spherical shape. N. scintillans lacks the armor plates possessed by other types of dinoflagellates. And, unlike many other dinoflagellates, the chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

s of the Noctiluca are not clearly visible and condensed throughout its lifecycle.


N. scintillans has a ventral groove within which is located a flagellum, an extension of the cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 wall called a tooth, and a striated tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

 involved in ingestion
Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in the substance through the mouth into the gastrointestinal tract, such as through eating or drinking...

 that projects posteriorly. The flagellum does not move the organism and therefore the non-motile N. scintillans depends upon regulation of its buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 within the water column – perhaps by controlling its cellular concentration of ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

s and ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...


At least one study has shown that a string of mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...

 is produced by N. scintillans extending from the tip of the tentacle which then adheres to plankton as it ascends rapidly through concentrations of its prey in the water column.


High concentrations of their plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

 food source that likely result from environmental conditions such as well-mixed nutrient-rich waters and seasonal circulation
Circulatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

 factors are implicated in population blooms of N. scintillans, known as “red tides”.

Swimmers may report being illuminated by a ghostly glow-in-the-dark plankton - a floating bloom of algae which fires up into a fluorescent sparkle when disturbed. This gives Noctiluca scintillans the popular names "Sea Ghost" or "Fire of Sea".

Runoff from agricultural pollution may contribute to the severity of these blooms. However this is not required to cause explosive growth of Noctiluca scintillans.

Not all blooms associated with N. scintillans are red. The color of N. scintillans is in part derived from the pigments of organisms inside the vacuoles of N. scintillans. For instance, green tides result from N. scintillans populations that contain green-pigmented prasinophytes (green plant algae, Subphylum Chlorophyta) that are living in their vacuoles.

N. scintillans itself does not appear to be toxic, but as they feed voraciously on phytoplankton high levels of ammonia accumulate in these organisms which is then excreted by N. scintillans into the surrounding area which may add to the neurotoxic chemicals being produced by other dinoflagellates, such as Alexandrium spp. or Gonyaulax spp., that do result in the death of other aquatic life in the area.

Other References

  • Eckert R & Reynolds GT. 1967. "The Subcellular Origin of Bioluminescence in Noctiluca miliaris". J Gen Physiol. 50 (5): 1429-58.
  • Elbrächter, M. and Y. Z. Qi. 1998. "Aspects of Noctiluca (Dinophyceae) population dynamics." In: D.M. Anderson et al., Physiological Ecology of Harmful Algal Blooms. NATO ASI Series, Vol. G 41. Berlin: Springer-Verlag, pp. 315-335.
  • Hausmann, Klaus; Hulsmann, Norbert; & Radek, Renate; "Protistology" (3rd Edition) 2003. in E. Scheizerbart’sche Verlagsbuchhandlung.
  • Lenaers, Guy; Christopher Scholin, Yvonne Bhaud, Danielle Saint-Hilaire and Michel Herzog. 1991. "A molecular phylogeny of dinoflagellate protists (Pyrrhophyta) inferred from the sequence of 24S rRNA divergent domains D1 and D8." Journal of Molecular Evolution. Volume 32: 1; pp. 53-63
  • Murray, Shauna; Marten Flø Jørgensen, Simon Y.W. Ho, David J. Patterson, and Lars S. Jermiin. 2005. "Improving the Analysis of Dinoflagellate Phylogeny based on rDNA." Protist. Vol. 156, 269-286
  • Palmer, Jefferey D. 2003. "The Symbiotic Birth and Spread of Plastids: How Many Times and Whodunit?" J. Phycol. 39, 4-11
  • Tada, Kuninao; Santiwat Pithakpol, Rumiko Yano and Shigeru Montani. 2000. "Carbon and nitrogen content of Noctiluca scintillans in the Seto Inland Sea, Japan." Journal of Plankton Research. Vol.22 no.6 pp.1203-1211
  • Thomas Kiørboe and Josefin Titelman. 1998. "Feeding, prey selection and prey encounter mechanisms in the heterotrophic dinoflagellate Noctiluca scintillans." Journal of Plankton Research. V20: 8 pp. 1615-1636
  • Umani, S. Fonda; A. Beran, S. Parlato, D. Virgilio, T. Zollet, A. De Olazabal, B. Lazzarini and M. Cabrini. 2004. "Noctiluca scintillans in the Northern Adriatic Sea: long-term dynamics, relationships with temperature and eutrophication, and role in the food web." Journal of Plankton Research. 26(5):545-561

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.