dcsimg

Ecology

provided by NMNH Marine Dinoflagellates
Cells of G. toxicus are frequently found as epiphytes on macroalgae and dead coral. Different strains apparently exhibit a preference for certain algae; e.g. the Hawaiian strain prefers the red alga Spyridia filamentosa (Shimizu et al. 1982). Cells readily attach to substrates via mucoid strands originating from the sulcal area (Steidinger & Tangen 1996).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Etymology

provided by NMNH Marine Dinoflagellates
The genus 'Gambierdiscus' was named after the Gambier Islands from which it was discovered and also the discoid shape of the cell. The species name 'toxicus' is derived from the toxin-producing nature of this species.
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Habitat and Locality

provided by NMNH Marine Dinoflagellates
This species was identified from tropical reefs in the Pacific Ocean (Adachi & Fukuyo 1979; Fukuyo 1981), the Indian Ocean (Quod 1994), and the U.S. Virgin Islands (Carlson & Tindall 1985). Populations have been found in tidal pools and lagoons, as well as in colored sand, in the Caribbean (Faust 1995). In the United States, G. toxicus has been collected in waters around Hawaii (Taylor 1979; Shimizu et al. 1982) and the Florida Keys (Bergmann & Alam 1981; Besada et al. 1982; Loeblich & Indelicato 1986).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Morphology and Structure

provided by NMNH Marine Dinoflagellates
G. toxicus is a photosynthetic species with yellow to golden-brown chloroplasts and a large crescent-shaped nucleus (Fig. 5) (Adachi & Fukuyo 1979).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Nomenclatural Types

provided by NMNH Marine Dinoflagellates
Holotype: Gambierdiscus toxicus Adachi and Fukuyo, 1979: figs. 1-7
Type Locality: South Pacific Ocean: Gambier Islands, French Polynesia
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Reproduction

provided by NMNH Marine Dinoflagellates
G. toxicus reproduces asexually by binary fission.
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Species Comparison

provided by NMNH Marine Dinoflagellates
This species resembles Heteraulacus in tabulation, but differs by its right-handed girdle torsion, large apical closing plate, and a pouch-like sulcal depression (Taylor 1979). Gambierdiscus toxicus shares a number of characteristics with G. belizeanus. They both have the same plate formula, and have similar apical pore, cingulum, sulcus, general cell shape (lenticulate and antero-posteriorly compressed), and golden brown chloroplasts. However, they differ in a number of distinct features. Architecturally, both species have similar epithecal plates, but differ in thecal surface morphology: G. toxicus has a smooth surface with scattered fine pores, whereas G. belizeanus has a deeply areolated surface. G. toxicus is considerably larger than G. belizeanus. And plate 1p is broad in G. toxicus, whereas it is long and narrow in G. belizeanus (Faust 1995).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Species Overview

provided by NMNH Marine Dinoflagellates
Gambierdiscus toxicus is an armoured, marine, benthic dinoflagellate species. It is a toxic species that was discovered attached to the surface of brown macroalgae in the Gambier Islands, French Polynesia.
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Synonyms

provided by NMNH Marine Dinoflagellates
Diplopsalis sp. Yasumoto et al., 1977
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Taxonomic Description

provided by NMNH Marine Dinoflagellates
Species in this genus are anterio-posteriorly compressed and are observed in apical or antapical view. The epitheca and hypotheca are not noticeably different in size. A distinguishing feature is the shape and size of the apical pore complex (APC) (Fig. 1) (Faust 1992).
Cells of Gambierdiscus toxicus are large, round to ellipsoid (Figs. 1, 2, 4, 5), and flattened anterio-posteriorly. The epitheca and hypotheca are nearly equal in height. The cell surface is smooth with numerous deep and dense pores (Figs. 1, 3). Thecal plates are very thick. Cells range in size from 24-60 µm in length, 42-140 µm in transdiameter, and 45-150 µm in dorso-ventral depth (Adachi & Fukuyo 1979).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Thecal Plate Description

provided by NMNH Marine Dinoflagellates
The plate formula of Gambierdiscus toxicus is: Po, 3', 7'', 6c, 8s, 5''', 1p, 2'''' (Faust 1995). The apical pore plate (Po) is oval to ellipsoidal with a characteristic fishhook shaped apical pore (Figs. 1, 3), the opening of which is always oriented ventrally. Apical plate 2' is subrectangular and is the largest of the three apical plates (Figs. 1, 6) (Adachi & Fukuyo 1979). The epitheca is slightly indented ventrally (Figs. 1, 4). The hypotheca is deeply excavated ventrally (Figs. 2, 5, 6) (Adachi & Fukuyo 1979; Fukuyo 1981; Taylor 1979).
In the hypotheca the postcingular plate 1''' is triangular; its right corner extrudes, curves inside, and contacts antapical plate 1'''' (Figs. 2, 6) (Adachi & Fukuyo 1979; Fukuyo 1981). The posterior intercalary plate (1p) is broad and pentagonal (Figs. 2, 6). During cell division the sutures widen, the 1p plate changes its shape to rhomboid (Fukuyo 1981).
The cingulum is circular, narrow and deeply excavated, and ascends slightly (Adachi & Fukuyo 1979; Bagnis et al. 1979; Taylor 1979). The cingular wall consists of six plates and measures nearly 5 µm in width. It is bordered by a low, thick ridge which is made up of the folding of pre- and postcingular plates (Figs. 1, 4) (Adachi & Fukuyo 1979).
The sulcus is short, deeply concave and pouch-like, and is oriented to the right (Figs. 2, 5) (Adachi & Fukuyo 1979; Bagnis et al. 1979; Taylor 1979). Along the sulcal margin, an overhanging ridge continues along the edge of postcingular plate 5''', and antapical plates 1'''' and 2'''' (Fig. 2) (Adachi & Fukuyo 1979).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Toxicity

provided by NMNH Marine Dinoflagellates
G. toxicus is known to produce the following toxins: ciguatoxin (Yasumoto et al. 1987; Murata et al. 1990; Yasumoto et al. 1993); gambieric acid (Yasumoto et al. 1993); and maitotoxin (Yasumoto et al. 1977; 1993; Yokoyama et al. 1988).
license
cc-publicdomain
bibliographic citation
Faust, Maria A. and Rose A. Gulledge. Identifying Harmful Marine Dinoflagellates. Smithsonian Contributions from the United States National Herbarium, volume 42: 1-144 (including 48 plates, 1 figure and 1 table).

Gambierdiscus toxicus

provided by wikipedia EN

Gambierdiscus toxicus is a species of photosynthetic unicellular eukaryote belonging to the Alveolata, part of the SAR supergroup. It is a dinoflagellate which can cause the foodborne illness ciguatera,[1] and is known to produce several natural polyethers including ciguatoxin, maitotoxin, gambieric acid, and gambierol.[2][3] The species was discovered attached to the surface of brown macroalgae.[2]

History

This species was first described by Adachi, R. & Fukuyo, Y in 1979 using samples collected around Gambier Islands.[4] Which was split into five different species (Gambierdiscus caribaeus, Gambierdiscus carolinianus, Gambierdiscus carpenteri, Gambierdiscus ruetzleri and Gambierdiscus toxicus) according to their morphological characteristic of thecal structure, and the sequence of both D1–D3 and D8–D10 regions in large-subunit rDNA.[5]

Distribution

This species can be found in tropical and subtropical regions in Pacific Ocean and Indian Ocean.[6] It is often found at the surface of various macroalgae, dead coral, sand and in water column[7] suggesting that the certain chemical compounds in algal exudates may play an important role in the process of attachment .[7] In the presence of light, the attached cell will detach from the substrate and start swimming in water column. When the disturbance is over the swimming cells will again attach to the matrix.[8]

Secondary metabolites

This algae species is capable of producing a variety of bioactive polyketide natural products such as ciguatoxin with characteristic fused-ring cyclic polyether structure. It is believed that the biosynthesis pathway involves epoxide as an intermediate which then undergoes a cyclization reaction to form the fused-ring cyclic polyether structure.[9]

References

  1. ^ "Cook Islands Biodiversity : Gambierdiscus toxicus - Ciguatera Dinoflagellate". Cookislands.bishopmuseum.org. Retrieved 2012-06-08.
  2. ^ a b Faust, MA and Gulledge (2002). "Identifying Harmful Marine Dynoflagellates". 42: 1–144. {{cite journal}}: Cite journal requires |journal= (help)
  3. ^ Cuypers, E.; Abdel-Mottaleb, Y.; Kopljar, I.; Raes, A. L.; Snyders, D. J.; Tytgat, J (2008). "Gambierol, a toxin produced by the dinoflagellate Gambierdiscus toxicus, is a potent blocker of voltage-gated potassium". Toxicon. 51 (6): 974–983. doi:10.1016/j.toxicon.2008.01.004. PMC 2597072. PMID 18313714.
  4. ^ ADACHI, Rokuro; FUKUYO, Yasuwo (1979). "The Thecal Structure of a Marine Toxic Dinoflagellate Gambierdiscus toxicus gen. et sp. nov. Collected in a Ciguatera-endemic Area". Nippon Suisan Gakkaishi. 45 (1): 67–71. doi:10.2331/suisan.45.67. ISSN 1349-998X.
  5. ^ Litaker, R. Wayne; Vandersea, Mark W.; Faust, Maria A.; Kibler, Steven R.; Chinain, Mireille; Holmes, Michael J.; Holland, William C.; Tester, Patricia A. (September 2009). "Taxonomy of Gambierdiscus including four new species, Gambierdiscus caribaeus, Gambierdiscus carolinianus, Gambierdiscus carpenteri and Gambierdiscus ruetzleri (Gonyaulacales, Dinophyceae)". Phycologia. 48 (5): 344–390. doi:10.2216/07-15.1. ISSN 0031-8884. S2CID 86334317.
  6. ^ Tester, Patricia A.; Litaker, R. Wayne; Berdalet, Elisa (January 2020). "Climate change and harmful benthic microalgae". Harmful Algae. 91: 101655. doi:10.1016/j.hal.2019.101655. ISSN 1568-9883. PMID 32057343.
  7. ^ a b Parsons, Michael L.; Settlemier, Chelsie J.; Ballauer, Josh M. (April 2011). "An examination of the epiphytic nature of Gambierdiscus toxicus, a dinoflagellate involved in ciguatera fish poisoning". Harmful Algae. 10 (6): 598–605. doi:10.1016/j.hal.2011.04.011. ISSN 1568-9883. PMC 3182139. PMID 21966283.
  8. ^ Nakahara, Hiroyuki; Sakami, Tomoko; Chinain, Mireille; Ishida, Yuzaburo (June 1996). "The role of macroalgae in epiphytism of the toxic dinoflagellate Gambierdiscus toxicus (Dinophyceae)". Phycological Research. 44 (2): 113–117. doi:10.1111/j.1440-1835.1996.tb00385.x. ISSN 1322-0829. S2CID 84070794.
  9. ^ Van Wagoner, Ryan M.; Satake, Masayuki; Wright, Jeffrey L. C. (2014-06-16). "Polyketide biosynthesis in dinoflagellates: what makes it different?". Natural Product Reports. 31 (9): 1101–37. doi:10.1039/c4np00016a. ISSN 0265-0568. PMID 24930430.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Gambierdiscus toxicus: Brief Summary

provided by wikipedia EN

Gambierdiscus toxicus is a species of photosynthetic unicellular eukaryote belonging to the Alveolata, part of the SAR supergroup. It is a dinoflagellate which can cause the foodborne illness ciguatera, and is known to produce several natural polyethers including ciguatoxin, maitotoxin, gambieric acid, and gambierol. The species was discovered attached to the surface of brown macroalgae.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN