Noctiluca scintillans 2289568 207774582 2008-04-24T03:50:36Z 118.109.73.210 {{Taxobox | color = #FA7B62 | name = ''Noctiluca scintillans'' | domain = [[Eukaryote|Eukaryota]] | regnum = [[Chromalveolata]] | superhylum = [[Alveolata]] | phylum = [[Dinoflagellate|Dinoflagellata]] | classis = [[Noctilucales|Noctiluciphyceae]] | ordo = [[Noctilucales]] | familia = [[Noctilucaceae]] | genus = ''[[Noctiluca]]'' | species = '''''N. scintillans''''' | binomial = ''Noctiluca scintillans'' }} '''''Noctiluca scintillans''''', also published as ''Noctiluca miliaris'', is a free-living non-[[parasitic]] marine-dwelling species of [[dinoflagellate]] that exhibits [[bioluminescence]]. The bioluminescent characteristic of ''N. scintillans'' is produced by a [[luciferin-luciferase system ]] located in thousands of spherically shaped [[organelle]]s, or “microsources”, located throughout the [[cytoplasm]] of this single-celled [[protist]]. Nonluminescent populations within the [[genus]] [[Noctiluca]] lack these microsources. ==Diet== ''N. scintillans'' is a [[heterotrophic]] (non-photosynthetic) organism that engulfs its food (phagotrophic) which primarily consists of [[plankton]], including [[diatom]]s and other dinoflagellates, such as fish eggs and [[bacteria]]. Diatoms are often found in the [[vacuole]]s (internal membrane-bound storage compartments) within these single-celled creatures. The diatom ''Thalassiosira sp.'' has been noted in the literature as a favored food source of these organisms. ==Distribution== ''N. scintillans'' can be found widely distributed throughout the world, often along the coast, in [[estuaries|estuary]], and shallow areas of the [[continental shelf]] that receive plenty of light which promotes the growth of the [[phytoplankton]] that make up a large portion of ''N. scintillans’s'' diet. ==Size== 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]]s of the ''Noctiluca'' are not clearly-visible and condensed throughout its lifecycle. ==Anatomy== ''N. scintillans'' has a [[ventral groove]] within which is located a flagellum, an extension of the [[Cell (biology)|cell]] wall called a tooth, and a [[striated]] [[tentacle]] involved in [[ingestion]] that projects [[posterior]]ly. The flagellum does not move the organism and therefore the non-motile ''N. scintillans'' depends upon regulation of its [[buoyancy]] within the water column – perhaps by controlling its cellular concentration of [[ion]]s and [[ammonia]]. At least one study has shown that a string of [[mucus]] 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. =="Blooms"== High concentrations of their [[plankton]] food source that likely result from environmental conditions such as well-mixed nutrient-rich waters and seasonal [[circulation]] factors are implicated in population blooms of ''N. scintillans'', known as “red tides”. Runoff from agricultural pollution may contribute to the severity of these blooms, but is not required to cause such events of explosive population growth. ''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 ''Alexandrium spp''. or ''Gonyaulax spp''., that do result in the death of other aquatic life in the area. 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 <ref>Pascher, 1914</ref>) that are living in their vacuoles. ==Evolutionary development== At least one study, based on small subunit (SSU) RNA data, found that the dinoflagellates are a monophyletic group and that within this group ''N. scintillans'' was among the earliest to diverge. Please see the phylogenetic tree below. Another study, based on large [[subunit rRNA]], supports the claim that [[heterotrophic]] species of dinoflagellates such as ''N. scintillans'' preceded the emergence of photosynthetic species. Photosynthetic species would have evolved by acquiring photosynthetic capability through secondary and even tertiary [[endosymbiosis]]. ''N. scintillans'' is also placed within a classification scheme that has a class Diniferea, or Dinophyceae, which includes nonparasitic dinoflagellates that lack armor plating.<ref>Hausmann et al. 2003</ref> ==Notes== <references/> ==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 [[Category:Dinoflagellates]] [[Category:Bioluminescent_organisms]] [[fr:Noctiluca miliaris]] [[ja:ヤコウチュウ]] [[ru:Ноктилюка]] [[sv:Mareld]] [[tr:Yakamoz]] [[vls:Zêevounksje]]